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PHYSIOLOGICAL CHEMISTRY.
496 rather than to that of Spallanzani (Phy siology, p. 16). Mr. Crosse’s important experiments (Trans. Lond. Elect. Society) should also not be forgotten in reference to this REMARKS point, though put forward by him in a true ON SOME ANNOUNCEMENTS CONTAINED IN philosophic spirit, biassed by no theory ; and some have not been able to repeat LIEBIG’S ORGANIC CHEMISTRY, although them, Mr. Crosse writes me word that a CHIEFLY DIRECTED AGAINST THE druggist at Bridgewater has lately succeeded. On the whole, seeing the illustrious names THEORIES AND OPINIONS by which the theory of equivocal generation is expressly supported, and seeing it to be a OF LIEBIG ON THE PROCESSES OF general fact that animalcular life accompaFERMENTATION, PUTREFACTION, nies putrefaction of the most opposite characAND CONTAGION: ter (viz., alcohol, &c., into vinegar, equally as well as fresh vegetable infusions into putrid), WITH I think we may fairly conclude, that whenNEW VIEWS OF COMPOUND ever we attempt to account for the reproducSUBSTANCES. tive power of putrefaction, we should never forget this simultaneous production (howAuthor HORATIO By " PRATER, Esq., London, of Experimental Inquiries in Chemical ever brought about) of animalcular life. Just in the same way is it with the reproPhysiology." ductive power of fermentation. Asalreadyobserved, De la Tour says that vegetable germs (Concluded from p. 461.) make their appearance in the same way as LET us now commence the subject of pu- animal germs make their appearance, in the trefaction. In Liebig’s section on the relation case just mentioned, of putrefaction. Heat between fermentation and putrefaction, it is and carbonic acid gas, too, are evolved in stated that " all bodies in fermentation fall both cases, as in vital action. And, further, into putrefaction, when there is a free access as in vital action, neither can go on, excepting of air; and all matters capable of putrefac- in a very limited i-angeof temperature. " Il tion enter into fermentation, in the same way faut que la liqueur soit a un certain dègré de as fermenting matters do."-(Liebig, p. 274.) chaleur," says Berzelius (Trait, tome vi.), From the phenomena of putrefaction may be speaking on this fact of fermentation ; and deduced the following general law : that a the same holds in putrefaction. I insist parbody can always be generated by the air, ticularly on the fact just mentioned, in confrom a solution of organic matter ; which firmation of the theory of vital action. body will have a power of reproducing itself, Liebig, in opposition to this view of the when put into a fresh organic solution. Thus, subject, says (p. 362), that the word life imas Liebig says, a piece of putrefying sub- plies something more than a reproduction of stance put into an organic solution excites matter, viz., also a reproduction of peculiar the same action throughout the solution; and forms; and justly does he say so, for even and blood have a form as we know that a substance cannot be made to putrefy, if the access of air be carefully excluded ; therefore the air would appear in tion and putrefaction there is also a reproIt appears to me some way to give origin to, or assist in render- duction of peculiar forms. ing obvious, the reproductive power in ques- that his comparison (Opus. cit., p. 360,) of It is also to be remarked, that in the reproduction of oxalic acid,—when a tion. connection with such reproductive power is weak solution of it is poured on oxamid,-to the appearance of infusoria : hence the pecu- the reproductions in fermentation and putreliarity that separates putrefaction from com- faction, is not only defective as regards there mon chemical actions, and makes it come being no reproduction of forms, but also as under the class of a vitalising or organic regards the simultaneous production of action. And so surely is this the case, that ammonia ; for that is reproduced at the same " infusory animals (worms) form at the same time (according to his account), and combines time, even with vinegar, and so large, Berze- with the oxalic acid, forming oxalate of amlius continues, (Trait, tome vi., p. 555, monia. Now as such is the state of the case, Vinaigre,) that they may often be perceived may it not be possible that oxalic acid merely without the microscope." I know that many, acts by contact (like different substances on along with Spallanzani, deny an actual for- peroxyd of hydrogen, &c. &c.), and, by that mation of animalcules by putrefaction ; but means only, turns the oxamid into oxalate of This view of the subject (be it we must not forget that Lamarck, Burdach, ammonia ? and Treviranus, are of entirely the opposite right or wrong) seems supported by the fact, opinion, and likewise that Müller, after care- that the quantity of free oxalic acid in solufully reviewing Bremser’s experiments and tion alwayss remains the same, however much observations on entozoa, seems to incline to oxamid is decomposed. But in addition to the theory of the physiologists just named, the fact in question being, perhaps, equally
PHYSIOLOGICAL CHEMISTRY.
being globular.Rut in the cases of fermenta-
497
explicable, without supposing any reproduction (in the strict sense of the word) at all, we are not to forget that there is no absorption of oxygen, or evolution of carbonic acid So that the analogy is or heat, in this case. very far from being complete; and yet it is the only one which a most distinguished organic chemist could bring forward in support of his theory. Even had he succeeded better in his attempt-even had there been more analogy, still, one such example would not, I think, have been sufficient to justify us in referring fermentation and putrefaction to mere common chemical actions ; for oxamid and oxalic acid are both com posed of organic elements, and, hence, we should conceive, might possibly have had, in some slight degree, the reproductive powers * in question. * It in this
might also
have been
mentioned, that supposed reproduction of matter (oxalic acid), the action is not begun by ’the same peculiar property that it is in fermentation, viz., by matter, in a state of case
of
a
decomposition (as Liebig says), communicating a like state to the matter in contact. But, surely, to have made the analogy perfect in theae cases, Liebig should have adduced an example, where this peculiar property of communicating its state of action was combined with another peculiar property, viz., a power of reproducing itself. But as in the case of platinum and silver in nitric acid, there is no reproduction of matter,—and even the apparent spreading of action being imaginary, as already observed in the note on fusion,-so in oxalic acid and oxamid the action is not commenced by matter in action communicating a like state to the matter in contact.
Again, when oxamid is boiled with many other acids, and even alkalies, it would appear that oxalate of ammonia is reproduced. - (Graham’s Elements, p. 407.) As it is probable, therefore, that the same line of argument used by Liebig for oxalic acid is equally applicable to other acids (and even alkalies), these may just as well be said to reproduce oxalic acid, as oxalic acid itself may be said to reproduce itself in the case in question. Now ferment cannot be reproduced by such opposite modes of action (that of acids and alkalies) ; but the agents that reproduce it have, according to Liebig’s own account, one property in common, viz., they are all in a state of incipient decomposition. Ferment, in fact, is reproduced but by ferment, or by the action of the air acting in some cases as a ferment. The fact is, oxamid is made from oxalate of ammonia, and differs from it only in having two atoms of water less ; and, consequently, any cause enabling it to get these two atoms of water turns it into oxalate of ammonia. But though ferment may be made from gluten by oxidation, no known means will change the ferment
Liebig has classed contagion among the same phenomena as fermentation and putrefaction, and this appears to me with reason. The defect seems to be, his attempt to refer all these (as well as combustion) to ordinary chemical action,
to action common to inor-
organic compounds. Like fermentation and putrefaction, contagion is action confined to organic matter, the blood being the truly living fluid on which ganic
as
well
as
an
such action is manifested. Yeast," says Liebig, " is produced from gluten, as the poison of cow-pox and smallpox is produced from the blood" (p. 378). In contagion, too, there is a reproduction of matter, and contagion is matter in a state of decomposition produced by a disease ; while miasm, which is the cause of contagion, is the same matter in a state of decomposition or putrefaction, in virtue of ordinary chemical affinity (pp. 380-81). By these remarks Liebig, in all probability, has in view to reduce contagion to exactly the same class of actions as putrefaction ; in fact, to show that it is the same action, only under different conditions: and we think his observations satisfactory in this respect, if, indeed, determinate forms (organic germs) are produced at the same time that the reproduction of matter takes place. Let us now pass to the action of combustion. With respect (as a general principle t) to the emission of carbonic acid gas, the spreading of action, and the generation of heat (only of a more intense character), combustion resembles fermentation and putrefaction. The spreading of action in combustion, makes combustion more nearly, at first sight, to resemble fermentation, where no gluten is present, but where the sole action is on sugar, a crystalisable, and therefore not an organic globular, form of matter. And as the spreading of action in this case is to a heterogeneous form of matter, in contact, so it may be likewise in the case of combustion. Thus, if in paper be set on fire, wood, fat, tar, &c., contact, may transmit the action, becoming successively inflamed. But in all these cases, the heterogeneity of substance is perhaps rather apparent than real, for they all resemble one another in containing carbon. But as phosphorus, sulphur, hydrogen, &c. &c., may likewise become inflamed by contact, under like circumstances, it is clear that in combustion an action begun in one form of
But notwithstanding that of oxamid is not satisfactory, I incline to the belief, as will be seen further on, that there is some very feeble reproductive power in inorganic matter. t There is no emission of carbonic acid gas in some cases, as in those of oxidation ; but in the present place we only regard combustion in reference to organic matters, in which there is the like emission of carbonic acid gas as in fermentation and putrefaction. into
gluten again. Liebig’s example
498 matter may be communicated to another, and alone (i. e., unaided by oxygen) cannot rea distinct form, of it ; in other words, that the produce itself, as we may observe, by heataction of combustion is communicable to ing metal wire. The heat runs all through heterogeneous matter in contact : and perhaps the wire, but at the expense of the heat first One end becomes cooler in proporeven in a more marked degree than in fer- given. mentation and putrefaction, for in these the tion as the other end becomes warmer. But heterogeneous matters in contact must be heat, in the circumstances in which it can composed principally of carbon, and be of produce combustion, has the power of genecomplex elements. Therefore, the commu- rating itself, just as much as generation is nication of action is more limited in these observed in fermentation, putrefaction, or latter cases, and indeed they may scarcely be life. And as none of these actions can take said to be heterogeneous matter; for, like the place without the presence of air or oxygen, matter exciting the action, the matter in con- so neither can combustion, in the sense geneThe circumtact must be composed principally of carbon, rally attached to that term. and be of complex elements. But in com- stances, then, in which heat can reproduce bustion, as just observed, it may be simple, itself, are precisely the same as those iu as sulphur, phosphorus, and truly heteroge- which life can reproduce itself; t in other neous in nature. words, in which matter is reproduced in ferNow all these observations tend to bring mentation or putrefaction-in our opinion, the action of combustion more nearly to the modified vital actions. The generation of phenomena of ordinary inorganic chemistry ; heat observed in flame is, doubtless, derived for it is the nature of a vital action to be con- from the action of the air : nor can it be fined to carbonaceous matter of complex ele- doubted that there is a real and constant ments, and in this predicament are fermenta- generation of heat in combustion ;;$other wise tion and putrefaction. But although the above observations establish some distinctions subject will induce us to consider the power between combustion, fermentation, and pu- causing the spreading of action to be the same, trefaction, I think that profounder reflection or nearly the same, as the power causing the will induce us to class all these phenomena reproduction of matter, or action. On this under the same head, the differences appear- view of the subject, the analogy between ing to arise rather from the want of propor- combustion and fermentation will be very tion in the intensity of action (for in combus- great. In heat, by itself, the action merely tion it is always more intense), and on the spreads;when the heated body can combine matter in this latter case being operated on with oxygen, heat itself is generated; and if in the dry state. Hence, in combustion, as flame be considered to be of a determinate we have seen, the action may be communi- form, a determinate form is likewise produced. cated to matter of a more heterogeneous t Nutrition seems a species of generation; nature than it can in putrefaction and fer- the different organs of the body appearing to mentation, the intensity of energy overcoming have the power of changing the blood that the resistance. Again, although combustion flows through them into themselves. In this is more strictly analogous to fermentation, way, muscle, brain, &c. &c., increase in size. where no gluten is present, still, on con- Each part, when a certain kind of matter is sideration, we shall find that the reproduction presented to it-undercertain conditions, as in of flame may well be likened to the reproduc- combustion-having the power of forming its tion of the determinate forms in fermentation like. Each part has a real generative power, or putrefaction, for the reproduction of flame and, as a necessary consequence, the whole, is in combustion the reproduction of self. under certain conditions, will have all these The matter in fermentation, to reproduce powers of generation combined. Accorditself, has need of a peculiar kind of matter ingly, we find that all living matter, even (gluten) to act upon ;so it is with nutri- that which appears produced in some cases tion-so it is with combustion. For heat by equivocal generation, as it has a power of nutrition, has likewise a power of generating * This view of the question, which has its like, as an essential property of its existsuggested itself after more careful reflec- ence. The law seems to be that like protion, will induce us to modify somewhat duces like, whether the parts be taken indivisome of the previous statements in this article : dually or collectively. at least, I think we may consider it to be a * This generation of heat depends, no doubt, general principle, whenever matter in action on the burning body being able, in consequence has the power of communicating that action of its heat, to absorb oxygen ; and thus the to heterogeneous matter in contact, that if further generation of heat depends on this absome other peculiar matter were also pre- sorption of oxygen, and, excepting in the consent, the matter that began the action would version of phosphorus into phosphoric acid, be able to reproduce itself out of this latterseems always in exact proportion to such matter. Just as we see yeast reproduce it-absorption.—(Despretz.) The probable cause self, when gluten is present ; but if gluten beof the exception in phosphorus arises from not present, no reproduction takes place, bult the combination with oxygen being more rapid only a spreading of action. This view of thtthan in other cases.
499
flame could never exist, and communicate that electricity must be admitted to be able itself in the way it does, but would, like to generate itself, just in the same sense that
metal wire heated only to a determinate ex- heat is admitted to do so. In fact, this power tent, heat only in proportion as it was itself of reproduction probably extends through all first heated. And if it be said that there is matter, in some slight degree, but can only be no determinate form in flame, as there is in manifested among complex elements (for vital products, that is only on account of a among simple saline compounds no action difference of intensity, &c., already men- like that between oxalic acid and oxarnid tioned. The form first given, is itself propa- could take place), whether of purely organic gated with the like intense nature;and this formation or not, probably will make no difis all that seems requisite to make the analogy ference. Iteproduction or generation, so far I will not say absolutely as mere ponderable matter is concerned, is almost perfect. perfect, because the form of flame cannot, in less mysterious than is commonly conceived, consequence of the conditions under which it when we remember that it is, in fact, only a is produced, be so definite as that of organic separation of the atoms (rather globules) of forms; but if we set aside the vegetable matter, and a different reunion of the same. germs produced in fermentation, and merely The mystery is in the reproduction of a new regard the generation of yeast, and the form like the old, rather than in the reprospreading of action, we shall find the analogy duction of the matter, which always must be rendered still more complete. produced out of something as material and But it may be asked, if the reproductive ponderable as it is itself. " Ex nihilo nihil action in life, fermentation, putrefaction, and fit" (humanly speaking)-is true, even where combustion,* only takes place in consequence it appears, at first sight, not to be true, viz., of the presence of oxygen, must we not admit in the generative power of living beings. Our electricity to generate itself after the same opinions, then, on this subject are similar to mode, the quantity of electricity being in those of Liebig; but until he has adduced the electrical machine in proportion to the more examples than that of oxamid and amount and rapidity of friction, and in the oxalic acid, and examples where spreading voltaic battery in proportion (or nearly so) of action of a quick character is combined to the amount of chemical action (oxidation) with reproductive power, we cannot regard I think we must admit the point as established, and must be conas in combustion? this to be the fact, only there is not so much tent only to look on it as the most probable appearance of generation in these cases, be- opinion. But though inclined to agree with Liebig cause the action does not seem to go on so i spontaneously, the machine necessarily re- that there is a generative power in ponderquiring the aid of another power to produce able matter, not only from his example of the friction, and the action in the voltaic bat- oxamid, but also because in ponderable tery going on imperceptibly, and without so matter there is something like a spreading of much visible change as in combustion. But, action, i. e., according to our views, a power more deeply considered, these seem mere that is capable of generating matter like illusions. If heat could generate itself with- itself, when placed in circumstances (as out the assistance of a further supply of oxy- already observed in a note lately made) that gen, we should then say the generation in admit it ;still, there is a difference in the such a case was different from what it is in power in question with regard to the velocity electricity ; but as it cannot, we conceive of movement, when fermentation, putrefac*
That is, in ordinary circumstances, so far as combustion is concerned ; in which sense I have all along spoken in reference to heat: for heat can reproduce itself by other modes, as well as by the action of oxygen. Thus, sometimes by iodine, but still more readily by chlorine, as the combustion that takes place when some metals are introduced into this, shows. The generation of heat in such cases must be immense. If heat be matter, what an immense quantity of it must be contained in such forms of it as ignite thus spontaneously by juxta-position! But heat cannot generate itself when carbon (wood or charcoal), even in a state of ignition, is put into chlorine : neither could the reproductive actions of fermentation, putrefaction, or life, go on in such circumstances ; so that the analogy between these actions and combustion, as generally understood, still holds.
tion, combustion, or electricity are concerned, that separates these cases of spreading of
action, in some degree, from those of decomIn all positions in saline solutions, &c. these latter cases, if the fluid to cause the decomposition be much lighter than the other, it will remain a long while without producing any precipitate; and even in cases where the fluids are of the same density, if one fluid be poured in very gradually, and no agitation or stirring be employed, the chemical action will be almost entirely confined to the parts of the solution where the fluids were put in contact; that is to say, the action will only extend downwards, in consequence of the force of gravity acting in that direction, and not laterally, which it ought to do if fluids had much power to spread the action. But in fermentation and putrefaction, though the ferment or putrid substance be put below, the action will soon run upwards
500 to the force of gra- the idea of latent heat from matter, you, of still more pointedly is this course, change the character of the matter, the case with combustion. The natural ten- and reduce it to the freezing state, in which dency of flame is upwards, perhaps in con- state spreading of action (from whatever sequence of the " gaseous matter heated to cause arising) must necessarily cease to whiteness," of which flame consists, being exist. So it seems better to say there is a rendered lighter, from its expansion by feeble degree of this power in matter in its heat, than the surrounding air. But how- ordinary state (to whatever cause it may be ever this may be, motion in some way or attributed), but a far greater degree of such another seems essential to the existence of power in light, heat, electricity ,t matter in flame : it extends rapidly in any direction* fermentation or putrefaction. where it can find nutriment (as it were), i. e., We are now prepared to sum up our concombustible matter. clusions on the subject of this essay. First. We do not think that Liebig has Again, as regards electricity and the chemical or mechanical effects produced by it. brought forward a single satisfactory examPlaced in conditions in which its equilibrium ple, in inorganic chemistry, of his principle, of is disturbed, it will move in any direction, matter in action being able to communicate and oppose almost any resisting power. that action, since the case of alloys cannot be Hence, then, in the cases just mentioned, the regarded in this light. In consequence, his spreading of action is decidedly active; but theory of fermentation and putrefaction, conin ordinary chemical decompositions it is sidered as a principle of action pervading in. rather of a passive character, and in reality organic matter, is untenable. can hardly be called a spreading of action. Nor is this conclusion weakened by our In my experiments with reference to in- agreeing with Liebig, that the spreading of herent activity, I found, when evaporation action in combustion is similar to that in ferwas prevented as much as possible, that mentation and putrefaction; for, in instancommon salt, placed at the bottom of a tube, cing combustion, he is instancing an action, remained without dissolving in water up to sui generis,—at least, one of a totally different character from that of alloys, &c. &c. the surface, for many days. I conclude, from all the above consideraSecondly. Although in the cases of fertions, that the feeble power of spreading of mentation and putrefaction Liebig has action, observable in inorganic solutions, is shown that the ferment must be in a state of probably derived from the latent heat, or decomposition itself, still it seems not imposelectricity, inherent in matter generally ; sible, even in that case, that action may be since both these agents, in a disengaged communicated, from other reasons than such state, possess the power in question to a so decomposing state of the ferment; such, for much greater degree. But if you separate instance, as the evolution of heat, the escape of carbonic acid, or some other changes, which * Since flame spreads so much more ra- this decomposing state of the ferment is necespidly even than putrefaction and fermenta- sary to produce. This point seems worthy tion, and since in these latter cases there is a of further investigation. slight elevation of temperature, may not this, That Berzelius’s principle of contact goes at least, materially assist, if not cause, the for something in these phenomena, is renprobable by the fact stated in Graham’s spreading of action in these cases ? This dered heat itself must be a cause of motion in de- " Organic Chemistry," just published, viz., composing organic solutions, to say no more. that " the elements of sugar assume totally Plutarch (certainly one of the most profound different arrangements -when the substances thinkers of his age), had singular ideas about that excite their transposition are in a differthe nature of flame. He says, in his " Ro- ent state of decomposition from the yeast: man Questions," in reply to the query, thus, when sugar is acted on by putrifying " Why the Romans did not extinguish a vegetable juices, t it is not converted into lamp or candle, but leave it to burn out of its own accord? Was it not because we are t Gases probably have this power more not to kill any animated nature that is harm- than any other form of inorganic matter, in less, fire being, as it were, such, for it both consequence of the great degree of latent needs nourishment and moves itself, and heat they possess. t I make this quotation, because I bebeing extinguished makes a noise as if slain." Had he confined himself to the two lieve this to be the true state of the case, the former points of analogy with living matter, assertion being the same in Berzelius’s even modern philosophy would have deemed Traite. Nevertheless, it seems at variance, the conjecture worthy consideration, at least in with Liebig’s statement (Op. so far as whether flame may not have life of cit., p. 258), " that gluten andligumine proa modified character; but when lie attempts voke fermentation in a solution of sugar, to press the analogy closer-to the higher when they are themselves putrid." To be order of animal life-and talks about the sure they provoke fermentation; but the noise of being slain, he raises a smile without above passage would lead us to believe that it is the vinous fermentation, instead of the intending to do so.
and laterally in
opposition
vity. Perhaps
-
some degree,
501
alcohol and carbonic
acid, but into lactic acid, mannite, and gum. Now, Liebig (Op. cit., p. 259,) obviously considers that yeast acts by being itself in a state of " putrid fermentation." If, then, a vegetable juice in that state excites a differ-
due to such latent vitality of the organic
matters (supposing I have shown such matters to retain vitality), so it seems most probable that even the reproduction of matter
upon merely as such, and distinct from a reproduction of ent sort of fermentation, the nature of the fer- form (animalcules or germs), is equally dement, or the peculiarity of action attached pendent on such latent vitality. At all to contact with it, must have some effects, as events this opinion will be tenable, until well as its being in a state of decomposition ; many more examples of reproduction of infor that this has also an effect we admit organic matter by itself have been brought that Liebig has shown. forward than that of oxamid and oxalic Thirdly. Although I do not think that acid. I would also insist particularly on the fact, Liebig, in adducing only the example of oxamid, has by any means done enough to that yeast cannot reproduce itself when only establish it as a principle that common in- gluten is present in solution (without sugw’), organic matter can, under particular eircuin- in favour of the opinion that the formation of stances, reproduce itself, I am still inclined yeast is not to be regarded as a mere case of to believe this to be the case, to a limited common oxidation. Else, why does not the extent, and consequently inclined to admit gluten change into yeast by absorbing oxygen with Liebig that the reproduction of yeast by from the air ? Why is the presence of sugar its own action on sugar and gluten, may be necessary? This question also strengthens merely a phenomenon of ordinary inorganic us in another of our conclusions (lately menchemistry. But it is worthy of remark, that tioned), viz., that the state of decomposition Liebig, in admitting that the production of of the ferment is not everything in exciting peculiar forms would assimilate fermentation fermentation. Why will not such decompoand putrefaction to vital actions, has omitted sition spread itself (to use Liebig’s term) to to notice the assertion of De la Tour with the gluten, when that alone is in solution regard to fermentation, and numerous other with the yeast? No; unless sugar be preauthors in regard to putrefaction, that in both sent, to which the action can first extend, those cases the 7’eproductire action is accom- gluten remains unaltered, and yeast cannot parzied with a production of peculiar forms, reproduce itself. The state of decomposition analogous to vegetable life in the former of the Sllgw’ will in this view rather be the case, and to animal in the latter. In conse- cause of the yeast reproducing itself-of the quence, even admitting that a mere repro- spreading of action necessary for that effect duction of like matter is hardly sufficient to -than the state of decomposition of the constitute fermentation and putrefaction vital yeast itself; and though, doubtless, such actions of the lowest degree, I cannot admit state of the yeast itself may be necessary, yet this, if it be true that animalcules of different we think Liebig has not sufiiciently insisted characters are produced simultaneously with on that mystery in the process of reproducthose processes ; and I think Liebig notjus- tion in the case of fermentation, viz., why a tified in overlooking this point. On the decomposing state of the sugar should be whole, therefore, as I think I have rendered necessary. it probable that alt organic matters may be 9, Stanhope-place, Hyde Park, said to retain a greater or less portion of December, 1841. vitality; and, as the phenomena of fermentation and putrefaction are never observed but in these, it seems almost demonstrated that EDUCATION or DRUGGISTS.—A medical the latent powers of vitality are concerned in gentleman of Baltimore, ordered for a convasuch processes : and as it is clear that ani- lescent patient half an ounce of phosphate of malcularlife, whenever it appears, must be soda; the prescription was taken to a druggist, who sent in its stead half an ounce of acetous, as seems most probable. Is there white oxide of mercury. The nurse in atnot a distinction in this respect between tendance, when about to mix the dose, sus-
(ferment), looked considered
as
_____________________________
————————————————————————————
putrid-animal and putrid-vegetable matters ? pecting it was not, sent it back to know if it Probably, as in vegetable decomposition, was right; the druggist declared it to be the acid is generally produced in the solution, medicine ordered. With this assurance, the which seems itself often a cause of the nurse gave to the patient the whole half acetous fermentation. (Berzelius, Fermenta- ounce, which proved fatal in thirty-six hours. tion.) I may here remark, that there seems A short time after the dose had been given some inconsistency in Graham’s chapter on the prescriber was sent for, and went to the fermentation, just quoted, and his chapter on druggist to see the bottle, which was marked decomposition by contact. (Elements, p. 195.) phosphate of soda, but contained white oxide But as that on fermentation was last written, of mercury. The druggist still persisting to he may be considered to acquiesce, though, the contrary, sufficient evidence was afforded perhaps, only to a certain extent, in Liebig’s that the mistake was not the result of acciviews.
dent,
but of
ignorance.—Dr. Bucklej’,
PHYSIOLOGICAL CHEMISTRY.
being globular.Rut in the cases of fermenta-
497
explicable, without supposing any reproduction (in the strict sense of the word) at all, we are not to forget that there is no absorption of oxygen, or evolution of carbonic acid So that the analogy is or heat, in this case. very far from being complete; and yet it is the only one which a most distinguished organic chemist could bring forward in support of his theory. Even had he succeeded better in his attempt-even had there been more analogy, still, one such example would not, I think, have been sufficient to justify us in referring fermentation and putrefaction to mere common chemical actions ; for oxamid and oxalic acid are both com posed of organic elements, and, hence, we should conceive, might possibly have had, in some slight degree, the reproductive powers * in question. * It in this
might also
have been
mentioned, that supposed reproduction of matter (oxalic acid), the action is not begun by ’the same peculiar property that it is in fermentation, viz., by matter, in a state of case
of
a
decomposition (as Liebig says), communicating a like state to the matter in contact. But, surely, to have made the analogy perfect in theae cases, Liebig should have adduced an example, where this peculiar property of communicating its state of action was combined with another peculiar property, viz., a power of reproducing itself. But as in the case of platinum and silver in nitric acid, there is no reproduction of matter,—and even the apparent spreading of action being imaginary, as already observed in the note on fusion,-so in oxalic acid and oxamid the action is not commenced by matter in action communicating a like state to the matter in contact.
Again, when oxamid is boiled with many other acids, and even alkalies, it would appear that oxalate of ammonia is reproduced. - (Graham’s Elements, p. 407.) As it is probable, therefore, that the same line of argument used by Liebig for oxalic acid is equally applicable to other acids (and even alkalies), these may just as well be said to reproduce oxalic acid, as oxalic acid itself may be said to reproduce itself in the case in question. Now ferment cannot be reproduced by such opposite modes of action (that of acids and alkalies) ; but the agents that reproduce it have, according to Liebig’s own account, one property in common, viz., they are all in a state of incipient decomposition. Ferment, in fact, is reproduced but by ferment, or by the action of the air acting in some cases as a ferment. The fact is, oxamid is made from oxalate of ammonia, and differs from it only in having two atoms of water less ; and, consequently, any cause enabling it to get these two atoms of water turns it into oxalate of ammonia. But though ferment may be made from gluten by oxidation, no known means will change the ferment
Liebig has classed contagion among the same phenomena as fermentation and putrefaction, and this appears to me with reason. The defect seems to be, his attempt to refer all these (as well as combustion) to ordinary chemical action,
to action common to inor-
organic compounds. Like fermentation and putrefaction, contagion is action confined to organic matter, the blood being the truly living fluid on which ganic
as
well
as
an
such action is manifested. Yeast," says Liebig, " is produced from gluten, as the poison of cow-pox and smallpox is produced from the blood" (p. 378). In contagion, too, there is a reproduction of matter, and contagion is matter in a state of decomposition produced by a disease ; while miasm, which is the cause of contagion, is the same matter in a state of decomposition or putrefaction, in virtue of ordinary chemical affinity (pp. 380-81). By these remarks Liebig, in all probability, has in view to reduce contagion to exactly the same class of actions as putrefaction ; in fact, to show that it is the same action, only under different conditions: and we think his observations satisfactory in this respect, if, indeed, determinate forms (organic germs) are produced at the same time that the reproduction of matter takes place. Let us now pass to the action of combustion. With respect (as a general principle t) to the emission of carbonic acid gas, the spreading of action, and the generation of heat (only of a more intense character), combustion resembles fermentation and putrefaction. The spreading of action in combustion, makes combustion more nearly, at first sight, to resemble fermentation, where no gluten is present, but where the sole action is on sugar, a crystalisable, and therefore not an organic globular, form of matter. And as the spreading of action in this case is to a heterogeneous form of matter, in contact, so it may be likewise in the case of combustion. Thus, if in paper be set on fire, wood, fat, tar, &c., contact, may transmit the action, becoming successively inflamed. But in all these cases, the heterogeneity of substance is perhaps rather apparent than real, for they all resemble one another in containing carbon. But as phosphorus, sulphur, hydrogen, &c. &c., may likewise become inflamed by contact, under like circumstances, it is clear that in combustion an action begun in one form of
But notwithstanding that of oxamid is not satisfactory, I incline to the belief, as will be seen further on, that there is some very feeble reproductive power in inorganic matter. t There is no emission of carbonic acid gas in some cases, as in those of oxidation ; but in the present place we only regard combustion in reference to organic matters, in which there is the like emission of carbonic acid gas as in fermentation and putrefaction. into
gluten again. Liebig’s example
498 matter may be communicated to another, and alone (i. e., unaided by oxygen) cannot rea distinct form, of it ; in other words, that the produce itself, as we may observe, by heataction of combustion is communicable to ing metal wire. The heat runs all through heterogeneous matter in contact : and perhaps the wire, but at the expense of the heat first One end becomes cooler in proporeven in a more marked degree than in fer- given. mentation and putrefaction, for in these the tion as the other end becomes warmer. But heterogeneous matters in contact must be heat, in the circumstances in which it can composed principally of carbon, and be of produce combustion, has the power of genecomplex elements. Therefore, the commu- rating itself, just as much as generation is nication of action is more limited in these observed in fermentation, putrefaction, or latter cases, and indeed they may scarcely be life. And as none of these actions can take said to be heterogeneous matter; for, like the place without the presence of air or oxygen, matter exciting the action, the matter in con- so neither can combustion, in the sense geneThe circumtact must be composed principally of carbon, rally attached to that term. and be of complex elements. But in com- stances, then, in which heat can reproduce bustion, as just observed, it may be simple, itself, are precisely the same as those iu as sulphur, phosphorus, and truly heteroge- which life can reproduce itself; t in other neous in nature. words, in which matter is reproduced in ferNow all these observations tend to bring mentation or putrefaction-in our opinion, the action of combustion more nearly to the modified vital actions. The generation of phenomena of ordinary inorganic chemistry ; heat observed in flame is, doubtless, derived for it is the nature of a vital action to be con- from the action of the air : nor can it be fined to carbonaceous matter of complex ele- doubted that there is a real and constant ments, and in this predicament are fermenta- generation of heat in combustion ;;$other wise tion and putrefaction. But although the above observations establish some distinctions subject will induce us to consider the power between combustion, fermentation, and pu- causing the spreading of action to be the same, trefaction, I think that profounder reflection or nearly the same, as the power causing the will induce us to class all these phenomena reproduction of matter, or action. On this under the same head, the differences appear- view of the subject, the analogy between ing to arise rather from the want of propor- combustion and fermentation will be very tion in the intensity of action (for in combus- great. In heat, by itself, the action merely tion it is always more intense), and on the spreads;when the heated body can combine matter in this latter case being operated on with oxygen, heat itself is generated; and if in the dry state. Hence, in combustion, as flame be considered to be of a determinate we have seen, the action may be communi- form, a determinate form is likewise produced. cated to matter of a more heterogeneous t Nutrition seems a species of generation; nature than it can in putrefaction and fer- the different organs of the body appearing to mentation, the intensity of energy overcoming have the power of changing the blood that the resistance. Again, although combustion flows through them into themselves. In this is more strictly analogous to fermentation, way, muscle, brain, &c. &c., increase in size. where no gluten is present, still, on con- Each part, when a certain kind of matter is sideration, we shall find that the reproduction presented to it-undercertain conditions, as in of flame may well be likened to the reproduc- combustion-having the power of forming its tion of the determinate forms in fermentation like. Each part has a real generative power, or putrefaction, for the reproduction of flame and, as a necessary consequence, the whole, is in combustion the reproduction of self. under certain conditions, will have all these The matter in fermentation, to reproduce powers of generation combined. Accorditself, has need of a peculiar kind of matter ingly, we find that all living matter, even (gluten) to act upon ;so it is with nutri- that which appears produced in some cases tion-so it is with combustion. For heat by equivocal generation, as it has a power of nutrition, has likewise a power of generating * This view of the question, which has its like, as an essential property of its existsuggested itself after more careful reflec- ence. The law seems to be that like protion, will induce us to modify somewhat duces like, whether the parts be taken indivisome of the previous statements in this article : dually or collectively. at least, I think we may consider it to be a * This generation of heat depends, no doubt, general principle, whenever matter in action on the burning body being able, in consequence has the power of communicating that action of its heat, to absorb oxygen ; and thus the to heterogeneous matter in contact, that if further generation of heat depends on this absome other peculiar matter were also pre- sorption of oxygen, and, excepting in the consent, the matter that began the action would version of phosphorus into phosphoric acid, be able to reproduce itself out of this latterseems always in exact proportion to such matter. Just as we see yeast reproduce it-absorption.—(Despretz.) The probable cause self, when gluten is present ; but if gluten beof the exception in phosphorus arises from not present, no reproduction takes place, bult the combination with oxygen being more rapid only a spreading of action. This view of thtthan in other cases.
499
flame could never exist, and communicate that electricity must be admitted to be able itself in the way it does, but would, like to generate itself, just in the same sense that
metal wire heated only to a determinate ex- heat is admitted to do so. In fact, this power tent, heat only in proportion as it was itself of reproduction probably extends through all first heated. And if it be said that there is matter, in some slight degree, but can only be no determinate form in flame, as there is in manifested among complex elements (for vital products, that is only on account of a among simple saline compounds no action difference of intensity, &c., already men- like that between oxalic acid and oxarnid tioned. The form first given, is itself propa- could take place), whether of purely organic gated with the like intense nature;and this formation or not, probably will make no difis all that seems requisite to make the analogy ference. Iteproduction or generation, so far I will not say absolutely as mere ponderable matter is concerned, is almost perfect. perfect, because the form of flame cannot, in less mysterious than is commonly conceived, consequence of the conditions under which it when we remember that it is, in fact, only a is produced, be so definite as that of organic separation of the atoms (rather globules) of forms; but if we set aside the vegetable matter, and a different reunion of the same. germs produced in fermentation, and merely The mystery is in the reproduction of a new regard the generation of yeast, and the form like the old, rather than in the reprospreading of action, we shall find the analogy duction of the matter, which always must be rendered still more complete. produced out of something as material and But it may be asked, if the reproductive ponderable as it is itself. " Ex nihilo nihil action in life, fermentation, putrefaction, and fit" (humanly speaking)-is true, even where combustion,* only takes place in consequence it appears, at first sight, not to be true, viz., of the presence of oxygen, must we not admit in the generative power of living beings. Our electricity to generate itself after the same opinions, then, on this subject are similar to mode, the quantity of electricity being in those of Liebig; but until he has adduced the electrical machine in proportion to the more examples than that of oxamid and amount and rapidity of friction, and in the oxalic acid, and examples where spreading voltaic battery in proportion (or nearly so) of action of a quick character is combined to the amount of chemical action (oxidation) with reproductive power, we cannot regard I think we must admit the point as established, and must be conas in combustion? this to be the fact, only there is not so much tent only to look on it as the most probable appearance of generation in these cases, be- opinion. But though inclined to agree with Liebig cause the action does not seem to go on so i spontaneously, the machine necessarily re- that there is a generative power in ponderquiring the aid of another power to produce able matter, not only from his example of the friction, and the action in the voltaic bat- oxamid, but also because in ponderable tery going on imperceptibly, and without so matter there is something like a spreading of much visible change as in combustion. But, action, i. e., according to our views, a power more deeply considered, these seem mere that is capable of generating matter like illusions. If heat could generate itself with- itself, when placed in circumstances (as out the assistance of a further supply of oxy- already observed in a note lately made) that gen, we should then say the generation in admit it ;still, there is a difference in the such a case was different from what it is in power in question with regard to the velocity electricity ; but as it cannot, we conceive of movement, when fermentation, putrefac*
That is, in ordinary circumstances, so far as combustion is concerned ; in which sense I have all along spoken in reference to heat: for heat can reproduce itself by other modes, as well as by the action of oxygen. Thus, sometimes by iodine, but still more readily by chlorine, as the combustion that takes place when some metals are introduced into this, shows. The generation of heat in such cases must be immense. If heat be matter, what an immense quantity of it must be contained in such forms of it as ignite thus spontaneously by juxta-position! But heat cannot generate itself when carbon (wood or charcoal), even in a state of ignition, is put into chlorine : neither could the reproductive actions of fermentation, putrefaction, or life, go on in such circumstances ; so that the analogy between these actions and combustion, as generally understood, still holds.
tion, combustion, or electricity are concerned, that separates these cases of spreading of
action, in some degree, from those of decomIn all positions in saline solutions, &c. these latter cases, if the fluid to cause the decomposition be much lighter than the other, it will remain a long while without producing any precipitate; and even in cases where the fluids are of the same density, if one fluid be poured in very gradually, and no agitation or stirring be employed, the chemical action will be almost entirely confined to the parts of the solution where the fluids were put in contact; that is to say, the action will only extend downwards, in consequence of the force of gravity acting in that direction, and not laterally, which it ought to do if fluids had much power to spread the action. But in fermentation and putrefaction, though the ferment or putrid substance be put below, the action will soon run upwards
500 to the force of gra- the idea of latent heat from matter, you, of still more pointedly is this course, change the character of the matter, the case with combustion. The natural ten- and reduce it to the freezing state, in which dency of flame is upwards, perhaps in con- state spreading of action (from whatever sequence of the " gaseous matter heated to cause arising) must necessarily cease to whiteness," of which flame consists, being exist. So it seems better to say there is a rendered lighter, from its expansion by feeble degree of this power in matter in its heat, than the surrounding air. But how- ordinary state (to whatever cause it may be ever this may be, motion in some way or attributed), but a far greater degree of such another seems essential to the existence of power in light, heat, electricity ,t matter in flame : it extends rapidly in any direction* fermentation or putrefaction. where it can find nutriment (as it were), i. e., We are now prepared to sum up our concombustible matter. clusions on the subject of this essay. First. We do not think that Liebig has Again, as regards electricity and the chemical or mechanical effects produced by it. brought forward a single satisfactory examPlaced in conditions in which its equilibrium ple, in inorganic chemistry, of his principle, of is disturbed, it will move in any direction, matter in action being able to communicate and oppose almost any resisting power. that action, since the case of alloys cannot be Hence, then, in the cases just mentioned, the regarded in this light. In consequence, his spreading of action is decidedly active; but theory of fermentation and putrefaction, conin ordinary chemical decompositions it is sidered as a principle of action pervading in. rather of a passive character, and in reality organic matter, is untenable. can hardly be called a spreading of action. Nor is this conclusion weakened by our In my experiments with reference to in- agreeing with Liebig, that the spreading of herent activity, I found, when evaporation action in combustion is similar to that in ferwas prevented as much as possible, that mentation and putrefaction; for, in instancommon salt, placed at the bottom of a tube, cing combustion, he is instancing an action, remained without dissolving in water up to sui generis,—at least, one of a totally different character from that of alloys, &c. &c. the surface, for many days. I conclude, from all the above consideraSecondly. Although in the cases of fertions, that the feeble power of spreading of mentation and putrefaction Liebig has action, observable in inorganic solutions, is shown that the ferment must be in a state of probably derived from the latent heat, or decomposition itself, still it seems not imposelectricity, inherent in matter generally ; sible, even in that case, that action may be since both these agents, in a disengaged communicated, from other reasons than such state, possess the power in question to a so decomposing state of the ferment; such, for much greater degree. But if you separate instance, as the evolution of heat, the escape of carbonic acid, or some other changes, which * Since flame spreads so much more ra- this decomposing state of the ferment is necespidly even than putrefaction and fermenta- sary to produce. This point seems worthy tion, and since in these latter cases there is a of further investigation. slight elevation of temperature, may not this, That Berzelius’s principle of contact goes at least, materially assist, if not cause, the for something in these phenomena, is renprobable by the fact stated in Graham’s spreading of action in these cases ? This dered heat itself must be a cause of motion in de- " Organic Chemistry," just published, viz., composing organic solutions, to say no more. that " the elements of sugar assume totally Plutarch (certainly one of the most profound different arrangements -when the substances thinkers of his age), had singular ideas about that excite their transposition are in a differthe nature of flame. He says, in his " Ro- ent state of decomposition from the yeast: man Questions," in reply to the query, thus, when sugar is acted on by putrifying " Why the Romans did not extinguish a vegetable juices, t it is not converted into lamp or candle, but leave it to burn out of its own accord? Was it not because we are t Gases probably have this power more not to kill any animated nature that is harm- than any other form of inorganic matter, in less, fire being, as it were, such, for it both consequence of the great degree of latent needs nourishment and moves itself, and heat they possess. t I make this quotation, because I bebeing extinguished makes a noise as if slain." Had he confined himself to the two lieve this to be the true state of the case, the former points of analogy with living matter, assertion being the same in Berzelius’s even modern philosophy would have deemed Traite. Nevertheless, it seems at variance, the conjecture worthy consideration, at least in with Liebig’s statement (Op. so far as whether flame may not have life of cit., p. 258), " that gluten andligumine proa modified character; but when lie attempts voke fermentation in a solution of sugar, to press the analogy closer-to the higher when they are themselves putrid." To be order of animal life-and talks about the sure they provoke fermentation; but the noise of being slain, he raises a smile without above passage would lead us to believe that it is the vinous fermentation, instead of the intending to do so.
and laterally in
opposition
vity. Perhaps
-
some degree,
501
alcohol and carbonic
acid, but into lactic acid, mannite, and gum. Now, Liebig (Op. cit., p. 259,) obviously considers that yeast acts by being itself in a state of " putrid fermentation." If, then, a vegetable juice in that state excites a differ-
due to such latent vitality of the organic
matters (supposing I have shown such matters to retain vitality), so it seems most probable that even the reproduction of matter
upon merely as such, and distinct from a reproduction of ent sort of fermentation, the nature of the fer- form (animalcules or germs), is equally dement, or the peculiarity of action attached pendent on such latent vitality. At all to contact with it, must have some effects, as events this opinion will be tenable, until well as its being in a state of decomposition ; many more examples of reproduction of infor that this has also an effect we admit organic matter by itself have been brought that Liebig has shown. forward than that of oxamid and oxalic Thirdly. Although I do not think that acid. I would also insist particularly on the fact, Liebig, in adducing only the example of oxamid, has by any means done enough to that yeast cannot reproduce itself when only establish it as a principle that common in- gluten is present in solution (without sugw’), organic matter can, under particular eircuin- in favour of the opinion that the formation of stances, reproduce itself, I am still inclined yeast is not to be regarded as a mere case of to believe this to be the case, to a limited common oxidation. Else, why does not the extent, and consequently inclined to admit gluten change into yeast by absorbing oxygen with Liebig that the reproduction of yeast by from the air ? Why is the presence of sugar its own action on sugar and gluten, may be necessary? This question also strengthens merely a phenomenon of ordinary inorganic us in another of our conclusions (lately menchemistry. But it is worthy of remark, that tioned), viz., that the state of decomposition Liebig, in admitting that the production of of the ferment is not everything in exciting peculiar forms would assimilate fermentation fermentation. Why will not such decompoand putrefaction to vital actions, has omitted sition spread itself (to use Liebig’s term) to to notice the assertion of De la Tour with the gluten, when that alone is in solution regard to fermentation, and numerous other with the yeast? No; unless sugar be preauthors in regard to putrefaction, that in both sent, to which the action can first extend, those cases the 7’eproductire action is accom- gluten remains unaltered, and yeast cannot parzied with a production of peculiar forms, reproduce itself. The state of decomposition analogous to vegetable life in the former of the Sllgw’ will in this view rather be the case, and to animal in the latter. In conse- cause of the yeast reproducing itself-of the quence, even admitting that a mere repro- spreading of action necessary for that effect duction of like matter is hardly sufficient to -than the state of decomposition of the constitute fermentation and putrefaction vital yeast itself; and though, doubtless, such actions of the lowest degree, I cannot admit state of the yeast itself may be necessary, yet this, if it be true that animalcules of different we think Liebig has not sufiiciently insisted characters are produced simultaneously with on that mystery in the process of reproducthose processes ; and I think Liebig notjus- tion in the case of fermentation, viz., why a tified in overlooking this point. On the decomposing state of the sugar should be whole, therefore, as I think I have rendered necessary. it probable that alt organic matters may be 9, Stanhope-place, Hyde Park, said to retain a greater or less portion of December, 1841. vitality; and, as the phenomena of fermentation and putrefaction are never observed but in these, it seems almost demonstrated that EDUCATION or DRUGGISTS.—A medical the latent powers of vitality are concerned in gentleman of Baltimore, ordered for a convasuch processes : and as it is clear that ani- lescent patient half an ounce of phosphate of malcularlife, whenever it appears, must be soda; the prescription was taken to a druggist, who sent in its stead half an ounce of acetous, as seems most probable. Is there white oxide of mercury. The nurse in atnot a distinction in this respect between tendance, when about to mix the dose, sus-
(ferment), looked considered
as
_____________________________
————————————————————————————
putrid-animal and putrid-vegetable matters ? pecting it was not, sent it back to know if it Probably, as in vegetable decomposition, was right; the druggist declared it to be the acid is generally produced in the solution, medicine ordered. With this assurance, the which seems itself often a cause of the nurse gave to the patient the whole half acetous fermentation. (Berzelius, Fermenta- ounce, which proved fatal in thirty-six hours. tion.) I may here remark, that there seems A short time after the dose had been given some inconsistency in Graham’s chapter on the prescriber was sent for, and went to the fermentation, just quoted, and his chapter on druggist to see the bottle, which was marked decomposition by contact. (Elements, p. 195.) phosphate of soda, but contained white oxide But as that on fermentation was last written, of mercury. The druggist still persisting to he may be considered to acquiesce, though, the contrary, sufficient evidence was afforded perhaps, only to a certain extent, in Liebig’s that the mistake was not the result of acciviews.
dent,
but of
ignorance.—Dr. Bucklej’,