AN ESSAY ON THE ATOMIC THEORY.

AN ESSAY ON THE ATOMIC THEORY.

492 sees them for the first time,! but she had been guilty of imprudences i under any but they are not dangerous; after a capable of producing abortio...

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492 sees them for the first time,! but she had been guilty of imprudences i under any but they are not dangerous; after a capable of producing abortion I may add that Madame hours they become calm, and are by an antispasmodic julep. The absence Carpenticr, who permits me to name her, of sudden suppression of the bleeding often has carried two children to the full _pe determines pain in the pelvis; in this case riod. Amongst the great number of I remove the clots contained in the vagina, women operated upon, I know only one and throw up warm emollient injections. in whom the cicatrix has completely ob. If the blood begins again to flow, the pains literated the orifice of the uterus. She usually disappear; if not, I cover the lower menstruated regularly, and in the ordipart of the abdomen with a poultice nary quantity; but each period was presprinkled with laudanum, and practise a ceded and accompanied by severe nervous revulsive bleeding of the arm. accidents, and some symptoms of metritis, when well-marked is which were soon dissipated. Besides, she to be treated according to the established never exhibited any signs of sanguineous accumulation in the uterus; the menstrual rules. A small revulsive bleeding from the arm discharge came from the surface of the vaThis woman died. On examining is also the best means of combating the we found some lymphatic ganglia en. consecutive discharges of blood which I may exist either with or without uterine gorged in the pelvis ; a chronic abscess unof the psoas muscles; no metritis pain. The rules of diet are too simple to de- or peritonitis; but it was evident that the serve any particular notice. lower orifice of the uterus was obliterated. introduction of a probe from time to As soon as all danger of hemorrhage time would prevent this accident. In removed, it will be advantageous to into the vagina a. small quantity of mallow- cases where it did take place, couldee w ater nearly cold, in order to remove any remedy it by the trocar or bistoury ? Ex. sanguineous clots which may remain, and perience must decide that question. which putrify with great rapidity. In drawingthis lecture to a close, I have The wound, however, made in the uterus, merely to remark, that of ninety-nine fee is not favourably circumstanced for a quick males in whom I have removed the neck of the uterus, fifteen are dead, and eightycicatrization, for, 1st. It is constantly bathed by liquids four are cured, and in the former the dismore or less irritating. ease was very considerably advanced. 2nd. The depression of the uterus ex- Wetherefore may hope, that as the new poses it to be rubbed against and injured. ideas on uterine disease become more 3rd. The organization of the uterus does extended, surgeons wiil be induced to openot permit its edges to come in close con- rate sooner, and thus the chances of failure tact; hence arises a pellicle of cicatriza- will be considerably diminished. Since this lecture was written, I have tion which covers a large surface, and requires a long- time to be perfectly formed. performed the amputation of the neck of The injection of emollient and then of the uterus three times. One patient is stimulant fluids, absolute rest, and the dead, the two others are under treatment. cauterization of the wound with the liquid —French Gazette, published June 20, 1834. proto-nitrate acid of mercury, should be employed according to the indications. Six or eight weeks are necessary to -obAN ESSAY ON tain the complete cicatrization of the wound. I cannot enter into the importTHE ATOMIC THEORY. ant question of the relapse of this disease, on which modern surgery, taking medi- By JOHN S. HILEY, Esq. Surgeon, Elland. cine as its basis, has thrown great light; and I must also pass over certain inconPART 11. veniences which many women experience IT was in 1808, an era the most eventful after their cure, but which are tlissipated The in the annals of chemistry, that this great soon by a very simple treatment. following, however, is an extremely im- man first published to the world his" New portant point of physiology. Amputation System of Chemical Philosophy," in which of the neck of the uterus proves that this was contained a brief view of his notions part of the organ is not indispensable to respecting atoms and definite proportions. pregnancy, which may take place and ter- It appears, however, from some observaminate fortunately without it. In general, tions made by Dr. Thomson in the hislabour is more easy. In ten patients who torical introduction to his " First Prinhad become pregnant after the operation, ciples of Chemistry," that he entertained one only was delivered at four months; these ideas much earlier, for in that work

surgeon who

few removedicircumstances.

Metro-peritonitis

Igina. her, I one der

L isThe

.

inject

.

-

493 I materials, and that in every place they as. Glaswegian Professor observes, first visited him (Mr. Dalton) at Man- sumed the same outward character. The chester, on the 26th of August, 1804, and atmospheric air which occupies the reon that day he explained to me his notions gions over the deserts of Africa, or blows respecting the composition of bodies." with such a freshness on the Andes, does Thus, this was four years earlier than the not vary more in its composition from "

the

period

when he made his invention ge- that which

we

breathe in the sunny climes

nerally known, and, consequently, from of England, than does the water of one 1804 the chemists of a future season will well differ from that of another. The probably date its origin. In the last law of similarity of composition seems to chapter of the first volume of the work be the same everywhere, and the unalluded to, he has given us a brief account changeableness preserved by elementary of his theory, and recorded its tenets in ’ substances is as apparent in this age as such simple colours, as to have greatly the inhabitants of the antediluvian surprised philosophers that the idea was world. However I might try to alter the not hit upon earlier. Previous to this !nature of matter, my attempts were as

with

pub-eternally

Dr. Thomson had thwarted as those of the allished in the third edition of his " System of old, for, I observed that it was of Chemistry a sketch of Mr. Dalton’s easier to turn the sun from his course than change the nature of the minutest theory; and in the same year, 1807, Wollaston showed that the proportionsof the acids in the three oxalates of potash, Hence I was led to conclude, that if naviz., the oxalate,-the binoxalate,—and ture preserved so strict a resemblance in the quadroxalate, were as the numbers the aggregate of her productions, the like 1,-2,-4. These with a variety of other law must extend to all her ultimate molefacts drew the attention of men of genius cules. I naturally imagined that if this to the subject, and amongst the rest, the were not the case, the properties and the of her various products must deserviugly celebrated Sir Humphrey Davy, and to crown all, in the succeeding be continually changing ; that if the atoms year, the opinions and views which were of which they were composed were not held by the discoverer himself, were re- indivisible and immutable, but admitted ceived from his own nen. of infinite division, the surfaces of those From the simplicity of the principles on atoms, a if such they might be termed, would 1 which the corpuscular theory is abraded, disfigured, and worn by become i it has always been a matter of so that instead of the aggregates of surprise to me that it was not invented tt maintaining their usual similarityof earlier. And this surprise has been much i they would after a season particiheightened by the fact, that ever since I pate in the common injury. knew how to think, indeed long before Nothing will better illustrate this fact I could possibly have any idea of than the following passage : A. number of system in question, I imagined that all atoms in the shape of minute cubes to matter must be united in definite propor make a larger cnbe, if abraded and worn tions. This idea was confirmed by a by use as they naturally would be, proknowledge that the natural productions of viding we admit the infinite divisibility of the present day are exactly similar in matter, would not then form an exact appearance and properties to the products : cube, every trial would find it more and of former ages ; that the trees of the’ more out of square ; it would become deforest have every similarity in their trunks, ficient first in one part, and then in branches, leaves, flowers, and seeds, to another, till at last it no more resembled those which existed amongst the earliesti a perfect cube than a circle resembles of our ancestors; and that the seeds of a square. Would not this be the case Would not the various’ herbage never produce any with natural productions ? other vegetable than a specimen of that the particles entcring into their composiparticular family to -which they belong. tion be constantly suffering abrasion ? so I examined the daisy of one season, and that scarcely two things would be formed found subsequently that it did not vary alike. Where would be the harmony that a shade from that of the next; and now exists? The nodding oak, whose every succeeding year confirmed the ! symmetry of form has attracted the attruth of the observation. I found that all of men in all ages, would no more chemical salts, whether formed by nature resemble itself, than the gnat resembles or by art, in the sea, in the bowels of the the elephant. Abrasion of its particles earth, or in the laboratory of the chemist, might cause it to become stunted, shriwere exactly similar in their appearance velled, and puny, so that instead of our and properties. 1 found that they were woodlands being adorned with specimens made up of precisely the same portion of of vegetable growth, such as existed when

period, however, "

I chemists

Dr.. to

particle.

,

appearance

3 founded, infiniteuse,

them

form,

the

II

their

I

i

tention

491

the particles which formed them came when Sir H. Davy discovered the nature from the hands of their Maker, the inhabit- of chlorine, or determined the bases of ants of modern times

would behold

a race

the alkalies and earths.

Dalton’s suppo-

of

disfigured, worthless, puny shrubs. sitions, however, were not grounded so Neither would this change be confined to much on the truth of the old atomic hypothe vegetable world. Both the animal thesis, as on the fact, that bodies united in and mineral kingdoms would suffer as definite proportions. He did not lahour well, and what was fine and well-propor- to support the important law that atoms tioned in this age might be shrivelled and were indivisible, further than was neces-

deformed in the next. To admit the infi- sary for the true exhibition of his own nite divisibility of matter, we are also theory, but, like many besides him, he was compelled to acknowledge the impossibi- a firm believer in that law. He argued, lity of all natural productions remaining that when combination takes place hethe same in a succeeding as in a previous twixt two bodies, the particles of these age, for consequent upon this lay! is the bodies unite in the proportion of 1 to 1, fact that matter infinitely divisible must 1 to 2, 1 to 3, &c., and from this fact he constantly be enduring a greater or lesser thought that the relative weight of the atoms of each substance might be deducetl. change in itself. Anyhow, supposing the atomic theory The Daltonian system has been called by should be hereafter proved to be not only different names, as the " doctrine of defi. untenable but unphilosophical, we are no nite proportions," " chemical eq,,iivalents," losers in supporting its tenets. For if, "proportional numbers," &c. ; but owing to mathematically speaking, a particle pos- the ingenious hypothesis which its ùiscosessed of surface cannot otherwise than verer introduced into his paper, on the posadmit of being divided into parts, might sibility of bodies uniting in indivisible we not argue that an atom, supposed like atoms or particles, this happy invention any other body to be composed of parti- has been generally termed the ’-atomic cles, is rendered indivisible by the supe- theory." rior affinity exerted betwixt the particles But as this portion of the doctrine has of that atom ? This would at once relieve not been so universally received, it would us from the necessity of supposing, in op- probably be advisable to style it the "law position to all mathematical demonstra- of definite proportions," as not only being tion, an atom possessed of length, breadth, more applicable to the strict truth, but and thickness, incapable of being subdi- better suiting the genius of every variety vided in case we had the means, or that of readers. From this doctrine of definite the attraction present therein was di3- proportions then, according to Dalton, pelled. So satisfied am I of the truth and spring three laws, the truths of which are sublimity of this law, that I now consider not founded on any speculation, but estait to rank in point of importance with the blished and determined from the results laws of specific gravity, and the attraction of a vast number of experiments, which it of gravitation. would be almost folly in any one to oppose. It will now be necessary to state the The first of these propositions is, that nature of Dalton’s views of the atomic whenever two bodies combine, the union theory, and likewise to notice the im- is generally in fixed and invariable proprovements and modulations which this portions. The second, that the proporsystem has undergone from the other tion in which one substance unites with chemists who assisted in promulgating a second, is always the same in its union with a third. Thus 1 part of hydrogen by and extending it. This invention was first published to the weight unites with 8 of oxygen and 6 of world in 1808, in the first volume of Dal- carbon; and 6 of carbon combines with ton’s " New System of Chemical Philoso- 8 of oxygen, from which it will be learnt, phy." The year previous it had attracted. that the numbers 1, 6, and 8, are the considerable attention, in consequence of’ combining proportions of hydrogen, carthe papers of Wollaston and Thomson ;, bon, and oxygen. The third and last probut on the publication and explanation ofposition is, that when combination takes its laws by the inventor himself, the eyes place in more than one proportion, the of almost every philosopher in Europequantity of one substance is generally were drawn towards it. There was a ge- double, triple, or some multiple of, its neral movement in the ranks of chemistry, combining number. Thus the equiand a much stronger sensation created valent number of sulphur being 16, and amongst its followers than was the case! that of oxygen 8,

.! lowest

495

sulphur admits of the same change; and there are are two combinations of acids is double sulphuric .phurous .triple its proportion in the first and low- sulphur and hydrogen, est combination. The combining Here the quantity of oxygen in the suland

In

this,

as

II of

numberthus

in the former

instance, the of acid,

or

any other intermediate quan-

quantity of sulphur, in its second combi- tity from less than a drop, with every pronation with hydrogen, is precisely double portion of water. The knowledge, too, of that of its proportion in the first. These three propositions, however, deThe first, that serve further illustration. whenever two bodies combine, the union is generally in fixed and invariable proportions, admits of some slight modifications, as has been noticed in a former part of this essay, viz., in the instances of the union of the stronger acids with water, Here-the union water with alcohol, &c. is not definite, for a drop of water will iningle with a gallon of acid, or a gallon

bodies

unitingin

more

than

one

propor-

tion, might be adduced in proof of the nonuniversality of this law; but then, when consider that these quantities are alinvariably either double, triple, or some other multiple of the lowest equivalentnumber, and not an intermediate quantity, this objection immediately dipsappears. Instances of this nature have been already given, to which others might be added, thus : -

we

most

in the whole range of chemis-i tuents of - atmospheric air were to be more striking than the’ changed, what would be the results ? Inalmost universal presence of this canonstant suffocation, or a short feverish existIt ence. It was a change of the former kind throughout all chemical prevails so generally, that it would be pre- which caused so destructive a mortality in posterous and absurd in any one to attri-the celebrated Black Hole at Calcutta, and bute its existence to chance alone, and of instances are on record of cersuch importance is its nature, that we may tain death ensuing from the inspiration of probably impute the constant harmony oxygen in an undiluted state. The purity and similarity in all natural as well as aratmospheric air is as necessary to vegetificial productions, purely to its fixed and table, as to animal life, for where its dehas been affected or otherunchangeable character. Indeed, nothing can be more necessary to the beauty and rendered impure, vegetation has in’harmony of nature, for were it altered byvariably suffered. In a pure state it supa decree -of Providence, have we not every combustion, in an impure one it reason to believe that the aspect and na- ! extinguishes flame. Indeed, so necesture of the globe would be sary is its purity to the support of the changed ? And is it likely that this vegetable and animal economy, and comthat were it otherwise, respiracould be for the better, for where so much tion and combustion would cease. Inasbeauty already prevails, no one, I sume, can imagine that it could be much much as the existence of definite proporimproved. Were different proportions of tions is requisite in these instances, so the the two gases which form our water to be of unnumbered philosophers suhstituted for those by which it is now demonstrated, that this law is equally produced, where or how might the raging indispensable to the existence of all natuthirsts of summer be quenched? In no and artificial productions, for were it other proportions will oxygen and hydrothe properties and appearance of gen form this useful beverage, and in case the variety of matter now in being must of an alteration in its constituents, the change also, and, in all likelihood, as consequences must be manifest to every Shakspeare sublimely observes, one. The ground would be parched, vegetation would wither, every living thing I The cloud-capp’d towers, the gorgeous palaces, would die, and our springs and rivers The Botemti temples, the great globe itself, Yea, all that it inlierits, would diskolve. would be dried up. Again, if the consti-

Nothing,

try,

is

perhaps

compounds.

innumerable i of

Icomposition

wise

’ ports

materially

change

bustion,

pre-

experiments have ral

changed,

,

496 From substances uniting in definite pro- Thomson, Wollaston, and Berzelius, se. portions, we are enabled to form compound lected oxygen, because of its almost unibodies synthetically, and, in case of ana- versal presence in all important combinalysis, can correct any errors arising from tions. The opinions of these celebrated deficiency in manipulatory skill, which chemists disagree also in the relative otherwise would have escaped our notice. value which each has attributed to his difWere we about to decompose a carbonate ferent standard. Thus, according to of lime, we know how much carbonic acid Thomson, the atomic weight of oxygen

ought to be evolved ; thus, if from 50 grs. is 1,-according to Wollaston 10,—whilst of the carbonate of this earth, wedid not Berzelius rates it as high as 100. obtain 22 grs. of carbonic acid, we might This difference has, at one time and then conclude that either the experiment another, created considerable confusion, was faulty, or that our conclusions were though now, when the system is so well erroneous. On the other hand, did we understood, it is of little or no importance, wish to form muriatic acid, our object since in the one case, we have the advanwould be to mix a volume of hydrogen tage of whole numbers, whilst in the other equal 1, with a volume of chlorine equal we are merely compelled to have recourse 36. This is obvious, from the fact of 1 to fractions. But, as fractional parts, and 36 being the combining proportions of however small, are always attended with ’these gases necessary to the formation of difficulties from which integrals are muriatic acid. As in the instances before exempt, the disadvantages attending Thomalluded to, an atom or volume of chlorine son and Wollaston’s numbers will be imgas is 36 times heavier than an atom or mediately observed, .whilst those of Bervolume of hydrogen. Under this head it zelius, besides being exposed to this evil, will be necessary to give the definite or are far too high for ordinary talents to combining proportions of a few elementary comprehend, and what is worse, the intesubstances, and to point out the manner grals themselves being high, of course the in which they were first deduced. 1 have fractions are complicated in a correspondalready alluded to the chemical equiva- ing degree. Some chemists are disposed lents of a few bodies, but it will be neces- to think with Dr. Thomson that when the sary again to recount them. At the same scale of numbers is low, the fractions will time, for the better explanation of the not be more difficult to retain than high subject, such have been pitched upon as integral parts. Thus they argue that it is are most familiar to us. easier to recollect 4.5, the weight of an atom of chlorine according to Thomson, than it is to remember the integral 36 of Dalton’s scale. Now I doubt this, for in my opinion it is easier to bear in mind any whole number, however high, than to think of the lowestfraction. Nor is there, to my thinking, a greater effort cf the memory requisite to recollect 200 than 25, the former being the weight of an atom of gold, ac. cording to Dalton, and the latter the It may be noticed here, that any num- weight according to Thomson. Add to a worse evil attends the method of ber may be taken as the standard of com- this, the If be fixed the Glaswegian professor. Where there hydrogen upon, parison. above will be the weights or definite pro- are fractional parts joined to so many difportions of the rest; whereas, if oxygen ferent quantities, a repetition of the same be chosen as unity, of course the relative fraction could hardly be avoided, thus the value of the others will be diminished 8 number 5, 25, 75, occur repeatedly, and I times. Thusimagine no one will be disposed to deny that when this is the case, the ditficulty is by any means decreased. .

Now Dalton’s numbers are altogether free from these objections. He pitched upon hydrogen as unity, from its lightness, and from its combining in the smallest quantity, and, what is surprising, all the Different chemists have chosen different atomic weights of the other elements are standards, and have likewise altered their multiples of it by a whole number. This value. Dalton, Henry, and Davy, pitched is a great advantage, as we are enabled at upon hydrogen, on account of its being once to dispense with all fractions, and all

the

lightest

of all known bodies, whilst other substances being

compared with

a

497

body lighter than themselves, we have if 2,lli’ grains of hydrogen can combine only an ascending, instead of a descendingwith no more than 16. 944 grains of oxyand an ascending scale. Add to this thatgen ; or 4.234 grains of hydrogen unite the experiments of other chemists, and with 33.888 grains of oxygen, then the more particularly those of Dr. Prout, haverelation in which the latter stands to the rendered it probable that hydrogen is notformer will be as 8 to 1 ; for as 33. 888 : only the lightest element known, but the 4. 234 lightest body in nature, therefore, if fu- clude,

:: 8 :

1. From this we must conthat if the oxygen and hydrogen in water unite atom to atom, the atom of oxygen must be 8 times heavier than the atom of hydrogen, since 33.888 and 4. 234, when reduced to their lowest terms, are as 8 and 1 ; and the former is the weight of 100 cubic inches of oxygen, and the latter the weight of 200 cubic inches of hydrogen, these being the proportions in which they combine to form water. There are other rules for deducing the equivalent numbers of the simple elements, besides the one just recounted. Thus the atomic weights of oxygen and hydrogen may be derived from the specific gravities of those gases. Now the specific

researches should prove the truth of all chemists must, with Dalton, necessarily adopt it as the great standard of comparison, so that instead of variety of opinion prevailing on this subject, one grand and unalterable law will ultimately exist throughout every country where chemistry is cultivated. . it was noticed the atomic theory that if a standard could be pitched upon, it would he no difficult matter to determine the chemical equivalents of all other elements. Accordingly Dalton fixed upon hydrogen, and called it unity, and compared the combiningw eights of all other substances with this gas. The weight of gravity of hydrogen being 0. 0694, and hydrogen was deduced from its union that of oxygen being 1.111, by dividwith oxygen to form water. It was found ing the latter sum by the former, we obthat 2.117 grains was the weight of 100 tain the atomic weight ofoxygen. This cubic inches of hydrogen, and that 33.888 law, however, may be better demonstrated grains was the weight of 100 cubic inches by the following process :-Let us take x of oxygen. On passing the electric spark to represent the weight of the atoms in a through a mixture of these gases in simi- measure of hydrogen, then as 0. 0694 : lar proportions, it was discovered that 1. 111 :: 2x :16x. By reversing this prowhilst the whole of the hydrogen was cess we have the atomic’weight of hydrocondensed, but 50 cubic inches, or 16.944 gen. Thus, as 1. 111 : 0.0694:: 16x:2x. grains, of the oxygen disappeared. Com- Now 16x is the relative weight of the paring the volume of these-gases we find, atoms in a volume of oxygen, and 2x rethat, instead of oxygen being only eight; present the weight of an enual number times heavier than hydrogen, it is sixteen of the atoms of howtimes the weight. But the atomic weight ever 16x and 2x are reduced to their of oxygen, instead of being 1(i is only 8. lowest terms, they are as 1 to 8, for as The reason is this. I have shown that 2x: 16x :: 1 : 8. Hence we conclude, that 100 cubic inches of hydrogen weighing an atom of oxygen is 8 times heavier than 2.117 grains, can condense no more than an atom of hydrogen. 50 cubic inches of oxygen weighing 16.944 There is another method of determining grains, and as the atomic weights of all the relative weights of the atoms from the elements are determined from the pro- specific gravities of their gases-viz. by portions in which they enter into combi- comparing the sp. gr. of each gas, with nation with other bodies, the same law the weight and sp. gr. of atmospheric air. must necessarily extend to oxygen. Hence Atmosptieric air is considered unity, thus.

ture

this,

Now

in

hydrogen. When,

Now 1.000 represents the sp. gr. of air, - 1.111 that of oxygen,—30* 5 the weight of 100 cubic inches of air,-and 33. 8. 88 the weight of 100 cubic inches of oxyThis important law, besides extending to gen. The exact weight of 100 cubic inches of the gases being made out by the two last elements, is observed to be this rule, we have only to compare the present in other principles when in a products with the weight of the same gaseous state. It will, however, be seen measure of hydrogen, which, on account oxygen, strictly speaking, forms an of its lightness, was assumed by Dalton a: exception, being 16 in place of 8. This the standard thus, as as has been before alluded

thatdiscrepancy,

-

498 to, arises from oxygen

combining with from its union with oxygen, was placed at in the proportion of 50 cubic 16 ; but the experiments of Mr. J. M. Corinches of the former to 100 of the latter, bett, inserted in the b15th number of the instead of equal measures of each ele- Mechanic’s Magazine, seem to prove that ment. Hence, in this instance, the law it ought not to rank amongst elementary must undergo some slight alteration. This substances any longer, for, according to may be done by doubling the volume of the statements of that gentleman, he has hydrogen, or by halving that of oxygen. effected its decomposition by means of Thus we may either take the weight of lightning. I will transcribe the passage: 200 cubic inches of hydrogen-- that is, " I (Mr. Corbett) enclosed some sulphur 4. 234, or the weight of 50 cubic inches of in a glass tube of two feet long by one oxygen—viz. 16.944. If the former, it inch in diameter. I passed a very fine will be as follows:-spiral wire through the sulphur, and then fixed the whole in a metallic lightning 4.234 : 33.888 :: 1 : 8. conductor, which was insulated above the If the latter, it will be thus, as sulphur apparatus. The glass was so contrived, that any air coming from it would 2. lli :16. 944 :: 1 : 8 pass into a receiver placed for its recepIn either case the chemical equivalent tion. I now waited for the lightning to of oxygen is 8. The latter method is per’ pass down the rod, and on visiting the haps preferable, since, instead of two mea- spot, I found the spiral wire fused, and the sures of hydrogen, we have only one. lower part of the sulphur changed into a The atomic weights of the two gases, powder as white as snow, and my receiver hydrogen and oxygen, being determined full of hydrogen. I have named this new one or other of the three preceding substance thiogen ;* its sp. gr. is 1. 707. laws, chemists have it now in their power It has a great affinity for hydrogen, and to discover the definite proportions of converts muriatic acid into chlorine. It other elements. Thus the equivalent num- converts oil and fat into carbon in quite a ber in which sulphur united with oxy- new state, the carbon being white, soft, gen, being twice as heavy as the latter and nearly transparent, after having lost element, its atomic weight was fixed at its hydrogen. Thiogen decomposes phos16, in reference to hydrogen; for oxygen phorus by depriving it of hydrogen; the being 8 times heavier than hydrogen, sul- remainingpart is a new and very inflamphur, if as heavy again as oxygen, must mable gas, of the colour of chlorine." of necessity be 16 times heavier than hyIn all likelihood this decomposition of drogen. Hydrogen is the standard of sulphur will affect chemistry considerably. comparison for determining the propor- The atomic weight, the theories, and the tionals of all simple substances. In this nomenclature, will severally require corway we have the relative weights of the recting, and probably the discovery itself atoms of phosphorus, azote, iron, potas- will lead ultimately to the sium; and the other elements havebeen as- of other bodies hitherto considered simcertained. Having arrived at this point, it ple. By means of thiogen the metalsmay was not difficult to determine the definite possibly be decomposed, more proportions of the compound bodies. On arsenic, since the latter, besides being the discovery of a new substance, the ex- isomorphous with phosphorus, resembles perimentalist had only to find out in what it very closely in its other properties. Nothing was more gratifying to me than quantity it united with another, the equivalent of which had been previously ascer- the disclosure of this important fact, for it . tained, and then it was easy enough tohas often occurred to my mind, that could calculate in what proportion it would com- we anticipate the discoveries and rehine with all the rest. TheGlaswegiansearches of future chemists, we might beprofessor, Dr. Thomson, was muchin- hold the 55 substances, at this period condebted to the immutability of this law,sidered elementary, reduced perhaps to when he engaged himself so assiduously fewer than half a dozen. I have imaginin improving and extending the atomiced, from the almost invariable diffusion theory..His statements are supposed toof the three elements,hydrogen, oxygen, he very accurate, and it may not be super-and carbon, in all species of matter, that fluous to remind the student, that thewe must view in them the three great professor determined the weights of anagents by which the countless varieties of atom of the several elementary substancesmineril, vegetable, and animal substances, from their union with oxygen, or with hy-are formed. Sir Humphrey Davy, if he did not extend his views so far, certainly drogen, or with both. Till very lately, sulphur was considered thought that considerable changes would by all chemists as a simple element, and, as such, its equivalent number, deduced* From hydrogen

I

by

decomposition

especially

O

499

may

be truly held up as a pattern to all be effected by future chemists, and that the number of now-supposed simple bo- future experimentalists. Nor must the name of Wollaston be dies would be greatly diminished. Who would be surprised if nitrogen should be passed over without a eulogium. In his scale of chemical equivalents, he decomposed, or chlorine, iodine, and bromine, found to be nothing more than pe- has presented chemists with a most vaculiar modifications of the two great ele- luable instrument. Whilst it is a kind of to the young experimentalist, it ments, hydrogen and oxygen ? The like fate probably awaits several of iserves to correct and obviate the errors of the metals. Every year will supply us the manipulations of the philosopher. It with more powerful agents, and more per- presents to the eye a mass of information fect instruments of research, through of which those can form no conception whose assistance many facts may be who have not had an opportunity of exbrought to light " which are not dreamt amining it. It points out the element of in our philosophy." At one period which will decompose any other compound fire was considered the most powerful body, the proportion requisite to effect the agent which chemists were known to decomposition, and the quantity of salt possess, and until electricity came to be &c. resulting therefrom. The principles understood, it maintained its rank as such on which Wollaston’s scale was invented, in the opinions of the scientific world. are the following. It was noticed long Electricity then arrived at perfection, ago, that when two neutral salts decombut the discovery of Galvani predicted pose each other, the products themselves its early decline. At length the im-are neutral. This is invariably the case, provements which galvanism underwentfor under all circumstances and situations under Davy, the various purposes to91 parts of carbonate of soda require for which it was applied, and the power ittheir decomposition 94 parts of muriate was discovered to possess, claimed for it,, of lime, after which the resulting salts are in its turn, a pre-eminent place in the in-- neutral. The cause of this important vestigations of men of science. Hitherto) phenomenon may be traced partly to the it has been looked upon as the most ex-- same compound body always being of a traordinary power in existence, and off similar composition, and to the fact that course, like fire and electricity, will al-the carbonic acid possesses exactly the ways be used by the experimentalist, butt same power of combination and saturation in all likelihood the researches cf Mr.as the muriatic acid. Corbett have row directed the attention This is rendered more evident by the of chemists into a new and more wonder- circumstance that the 48 parts of lime ful channel, where they will find a stronger contained in the neutral muriate of lime, and more useful agent even than galva- equally neutralize the 38 parts of carbonic nism. In this way we are gradually ad- acid contained in the carbonate of soda, vancing towards perfection, and as such and that the53 parts of soda present in there is no telling what revolutions in all the latter salt, exactly saturate the 46 chemical theories a very few years may parts of muriatic acid present in the produce. Probably, could the sages of former. Similar laws extend to the acids ancient Greece look down upon the pre- and bases of all other neutral compounds. sent improved state of natural and expe- Thus 40 parts of sulphuric and 54 of nitric rimental philosophy, when compared with acid, will both neutralize 32 parts of soda its progress in their own days, they would and 78parts of baryta ; consequently, if not be more surprised than would the 72 grains of sulphate of soda in solution shades of Lavoisier, Priestley, Berthollet, be mixed with a solution containing 132 and Davy, might they be permitted to grains of nitrate of baryta; two neutral visit the laboratories of chemists a cen- salts are the result, the one soluble and the other insoluble. The soluble one, nitury hence. I am now deviating. After Dalton, the trate of soda, is equivalent to 86 grains, most deserving labourers in the atomic and the insoluble one, sulphate of baphilosophy are,Thomson,Wollaston, Prout, ryta, is equivalent to 118 grains. Now Davy, Berzelius, and Gay Lussac. To these numbers 40,—54,—32,—78, &c., the first our gratitude can never be suffi- are termed equivalents, and being always ciently expressed, as, through his exertions in the same proportions to form or to in the " Annals of Philosophy," &c., the effect decompositions of the neutral salts, scientific world was made acquainted with it is easy to see how they might be armany interesting facts relating to the ranged on the logometric scale of Gunter. invented He appears to In explanation of this scale it will be nehave been a most laborious workman, and cessary to remark, that on examining it, the patience, talent, and tact displayed in and pitching upon a certain number, we the course of his chemical investigations, shall find that there is precisely the same

synoptic guide

newly

system.

-

500 distance from half that number that there lustrated in a passage from Dr. Wollaston’s is between it and double its amount. Thusown writings. " If, for instance, the salt on measuring with a pair of compasses under examination be the common blue we perceive that the distance from 10 to vitriol, or crystallized sulphate of copper, 20 is equal to that from 20 to 40, and thatthe first obvious questions are,—1. How the space from 40 to 80 is the same asmuch sulphuric acid does it contain ? : 2. How much oxide of copper? 3. How from 80 to 160. This is the case with the other numbers marked on the scale,much water? He (the analytic chemist) for on whichsoever we may fix it will bemay not be satisfied with these first steps seen, that that number has the same re- in the analysis, but may desire to know lation to another at any distance above it,further the quantity, 4 of sulphur,-5 of that the number at the same distance’copper,—6 of oxygen,—7 of hydrogen. below has to the first. For instance, let As means of gaining this information, he us fix upon the number 24, and after- naturally considers the quantity of various wards take a second number above it, as re-agents that may be employed for dips. covering the quantity of sulphuric acid.16; it will then appear that a third at the same distance below 24 will have 8. How much barytes,-9 carbonate ofbathe same relation to 24 that 24 has to 16. rytes,-or 10 nitrate of barytes, would be i requisite for this purpose. 11. How much This will be 36, for as lead is to be used in the form of 12 nitrate 36 : 24 :: 24 : 16. of lead; and when the precipitate of, 13, It is not difficult to see how a scale on this sulphate of barytes, or, 14, sulphate of lead, obtained, it will be necessary that he principle might be applied to the chemical isshould know the proportion which equivalents of both elementary and com- either ofalso them contains of dry sulphuric and Wollaston accordingly pound bodies, He may also endeavour to asceradapted it to this purpose. A slider, with acid. numbers upon it, from 10 to 320, distanced tain the same point by means of 15, the in the manner above explained, was first quantity of pure potash, or 16, of carbofor the precipitaformed, and on each side of them were nate of potash, requisite He tion of the might also use copper. the names of substances, both placed zinc, or 18, iron, for the same purpose, simple and compound, in juxtaposition17, with the numbers representing their equi-and he may wish to know the quantities of sulphate of zinc, or 20, sulphate of valents. Thus, when the slider is in its .

all

number

19,

that will then remain in solution." proper position, 10 (which Dr. Wollaston With the exception of the sixth and lixed upon as the atomic weight of oxygen) will be opposite that element,-20 oppo-i seventh, all these questions may be satis. answered by bringing thenumber site sulphur,-and 40 opposite copper. Now sliding the scale to any other part, indicating the quantity u:ider examination the sulphur and copper will stand op-i opposite crystallized sulphate of copper, water. Occasionally, however, the posite a number bearing the same relation ;; with 5,will not answer other questions, as, to oxygen in point of quantity, as is the,, scale Thus by bringing oxy-! for instance, proportions below 10, in coilcase in the above. gen opposite 20 on the scale, or any other sequence of the series commencing at that number, 40 will be opposite sulphur, and number, but by doubling or using any convenient multiplier, as 10 or 100, the quan80 opposite oxygen, for as of substance (as for example, those 10 : 20:: 20: 40,-or as 10 : 40 :: 20 : 80.tity formed the union of either

I( iron,

factorily

of this scale is, that ascertain how much of a

Another great

carbon

by

with

hydrogen or

other element), and if we wish to halving or dividing the gross amount neutral salt will decompose another, by 10 or 100, according to the multiplier have only to adjust the scale which has been used, the problem is saThus, if we had 90 grains of sulphate oftisfactorily solved. Another imperfection i soda, and wished to know what weight ofwhich accompanies Wollaston’s scale, and nitrate of baryta would exactly lead to more or less confusion, I it, we have only to bring the number 90 ought to be guarded against. It is this. opposite sulphate of soda, when on lookconsequence of most chemists having ing for the nitrate of baryta we shall find now pitched upon hydrogen as unity, and the quantity requisite, viz. 160 grains. the atomic weight of oxygen as 8, the Would we know how much baryta is con- proportional numbers of Wollaston will tained hi l00tb. of the sulphate of that require a little adjusting. That chemist substance, our object would be to bring fixed upon oxygen as his standard of the number 100 opposite the sulphate, comparison, and called it 10; it will, who after which, on looking for harytes, the therefore, he seen, instantly, by information required is obtained. adopted hydrogen, that by a little The power of such a scale is further il- ; arithmetical skill the relations of the use

some

then we accordingly.

decomposemight

In

have

those

501



different numbers may be easily asce1’-’ ’ tained. The value of this instrument not only to the scientific, but also to the manufacturin- chemist, is exceedingly great. It was a most happy invention, as it answers a hundred questions which might occupy much time in arithmetical calculations to determine. Indeed so numerous are the advantages resulting from its use, that that student does himself great injustice who neglects to include it amongst his other apparatus. Since theformation of Wollaston’s, other scales have been introduced to the notice of men of science. Those of Brande and Reid are, perhaps, the best, inasmuch as those chemists have adopted the Daltonian equivalents, both of them fixing upon hydrogen as unity. For the use of medical students and junior chemists, they are desince it cidedly preferable to is not unlikely that hydrogen may be hereafter found to be the lightest of all bodies, in which case nothing can prevent the chemical world from adopting the opinions first promulgated by Dalton. I shall next notice the second propo-

directly

ncuf; la retraction permanente des doigts est une affection dont la cause svait ete jusqu’alors inconnue, et la nabout

ture au-dessus des ressources de l’art:

fetude de l’anatomie pathologique a révelé a M. Dupuytren un traitement efficace. On a ehcrchc dernièrement a ravir cette dccouverte a notre professeur, en l’attribuantà Sir A. Cooper," &c. The following extract from my notes of the anatomical lectures, delivered by Astley Cooper and Henry Cline at St. Thonans’ Hospital, will show that the merit of having first demonstrated the true knowledge of this affection, is not at celec least to be attributed to the ju&tly brated French surgeon. The notes were made from a lecture by that ingenious and excellent surgeon, the late Henry Cline, jnn., on the 8th of November, 1803, many years, as far as I can gather from the Baron’s lecture (p.?, No. 24), before he became informed of its true nature. "The aponCLU’osis palmaris isfound just under the 3Lin and fat of the hand, and, like the aponenrasic pedis, it defends from pressure ; it is attached at its upper part to the ligamentum annulare carpi; it its origin, then spreads itself is narrow sition. out amongst the cellular membrane of the and dips amongst the muscles ; it PERMANENT CONTRACTION OF has several cross bands, tying, as it were, processes together. Slitting into tenTHE FINGERS. dinous columns, it is inserted into the of the fingers, and bases of the To the Editor Of THE LANCET. Ir the following observations should be’! phaln.nges. " One or more of these tendinous coconsidered sufficiently important, I shall of the aponeurosis palmaria somefeel obliged by their insertion in an early lumns times becomes contracted and thickened ; o. of THE LANCET, as a translation of most generally one only is affected, but Baron Dupuytren’s clinical lectures on sometimes more, and proportionably so has been in that joursurgery published many fingers are bent into the palm of nal. 1 remam, very respectfully, &c., the hand. The treatment is easy and erlJOHN WINDSOR, JOHN WINDSOR. One uf the Surgeons to the Manchester cacious ; it consists in cutting through the aponeurosis with a common knife. in E e Institution, &c. Manchester, 5th month, 1834. performing the operation, carefully dissect through, fibre by fibre, the apcneurosis The history of surgical operations palmaris, in order to avoid the bloodand nerves underneath; the nnger inventions, by which human afflictions may be cured or alleviated, is a subjector fingers may be kept extended afternot only highly interesting in itself, as wards by a splint, for the flexor muscle tending to show the gradual improve- has in some degree become shortened, ments in our art, but also satisfactory and without this the disease might be rein ascribing to different persons their re- produced. spective merits in co-operating towards; " It may be distinguished from a constate of the flexor muscles, by all its perfection. I am induced to make these observa- the fingers being then generally drawn tions, by having read over the first of into the hand, or if one only, there is not same starting into the palm of the Baron Dunuytren’s clinical lectures on surgery, on permanent retraction of the hand when thefinger is stretched, as fingers, and, again, the recapitulating re- there is in a contracted state of the marks at the completion of the course. tendinous processes of the aponeuroIn the latter occur the following words: sis palmaris ; the latter feels like a very " Bous avons debute par une circonstance hard cord raising the skin, but the flexors too low to start thus, and are also heureuse, par un memoire sur un sujet

Wollaston’s,

palm,

at

the

thecæ

-

I

and

II vessels

tracted ! the

are

.