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Description of an improved gothic window-blind
On an Improved Gothic ~Zindow.Bli~d.
272
a brown flocculent substance is thrown down, which is incapable of exciting fermentation in a solution of sugar, while the liquid gives off a fla b offensive smell. If the infusion experimented on be stronger, then the change is different ; tile liquid becomes turbid from the separation of a yellowish adhesive substance, a good deal of gas is very slowly emitted, alcohol is formed, and tile deposit at the bottom oi" the vessel proves a pretty -active ferment to sugar. The acidity of' the liquid is but trifling, and its smell is somewhat disagreeable. These differences in the behavior of boiled wort may also depend upon the quantity of hops added, and the length of time during which, the ebullitioll had been continued. The effect produced in a spontaneousLy fermentable liquid by vegetable acids, or acid salts, such as cream of tartar, is a curious subject of'inquiry. From an experiment made upon some wort, it appeared not improbable that the result of such addition showed an iL~terference in the formation of lactic acid. W e know that when the juice of grapes, or currants and gooseberries, is exposed to the air, the vinous fermentation is set up apparently at once ; whereas in an unboiled infusion of malt, which is destitute of these substances, lactic acid seems to be first formed~ although ultimately the two fermentations go on together. I stated, when speaking e l the spontaneous decomposition of wheaten dough, that an acid state preceded that in which it became an alcoholic ferment; and if in this condition it be mixed with a dilute solution of common sugar, and the whole kept warm for several days, it furnishes a sour liquid which is rich in lactic acid, and from which white crystalized lactate of zinc is easily prepared. There is a tendency in the liquid~o run into the alcoholic fermentation, and to produce vinegar by a subsequent change, but still the quantity ot lactic acid so formed is very considerable. Common wheat-gluten then in its mode of decomposition strikingly resembles diastase ; like that substance it runs in succession through two different dynamic conditions ; it is successively a lactic acid, and an alcohol ferment ;. is it too much to expect that it might, by proper means, be detected in a third condition, namely, as a "sugar ferment," like diastase itself in the state in which it exists in malt ? Is it not possible that diastase, as a definite proximate principle, has no more existence than yeast ; that its powers are purely dynamic, and that it is, in short, nothing more than the gluten of the seed in one of its earliest stages of decomposition ? This is an interesting inquiry, but its prosecution will be somewhat difficult, from the rapidity with which these changes succeed each other; it must be remembered that no one has yet succeeded in getting diastase ia a state fit for analysis. "Mere. Lond. Chem. Soc,
Description of an Improved Gothic Window-Blind. .By Mrs. J~.MI~A GOODE. The ordinary method of fixing blinds for the upper parts of Gothic windows~ is to attach the material of which the blind is composed~ to VoL VII, 3an Sxutss.
No. 4,~APR1L, 1844.
24.
278
Mechanics, Physics, and Chemislry.
a frame of wood of the required form, which frame is fixed to that part of the window by screws, or otherwise. The principal inconvenience of this plan is that, when not required to shade the sun, the blind cannot be drawn up, but remains fixed, and thus darkens the apartment ia which it is used.
D
H
J
In order to obviate this defect, Mrs. Goode proposes to fix the roller A B, to which the holland, or other material, C C, is attached, across that part of the window where the contraction of the frame begins, the holland, or other material, being cut into the required shape, and the broad part being fixed to the roller A A. By attaching a line D, to the pointed end of the blind, and passing it over the pulleys G I-I I, fixed in the upper, or curved, portion of the frame, and thence round the pulley J, towards the bottom of the frame, and returning it to the roller to which it is secured, the blind is readily pulled up, or down. To keep the blind in shape, wire stretchers may be sewn in across the holland, or other material, used for the purpose. The blind described above is the simplest of the two patterns sent. Trans. Soc. Arts &c.
Description of an Improved Life-Bi~oy. By Com. BEADO~, R. 2/. Fig. 1, shows the buoy as it would appear when afloat. Fig. 2, a longitudinal section of part of the main float ; and fig. 3, .the mode of suspending the buoy at the stern of the vessel, and of letting it go when required. The buoy is a cylindrical tube A A, made either of copper, or
272
a brown flocculent substance is thrown down, which is incapable of exciting fermentation in a solution of sugar, while the liquid gives off a fla b offensive smell. If the infusion experimented on be stronger, then the change is different ; tile liquid becomes turbid from the separation of a yellowish adhesive substance, a good deal of gas is very slowly emitted, alcohol is formed, and tile deposit at the bottom oi" the vessel proves a pretty -active ferment to sugar. The acidity of' the liquid is but trifling, and its smell is somewhat disagreeable. These differences in the behavior of boiled wort may also depend upon the quantity of hops added, and the length of time during which, the ebullitioll had been continued. The effect produced in a spontaneousLy fermentable liquid by vegetable acids, or acid salts, such as cream of tartar, is a curious subject of'inquiry. From an experiment made upon some wort, it appeared not improbable that the result of such addition showed an iL~terference in the formation of lactic acid. W e know that when the juice of grapes, or currants and gooseberries, is exposed to the air, the vinous fermentation is set up apparently at once ; whereas in an unboiled infusion of malt, which is destitute of these substances, lactic acid seems to be first formed~ although ultimately the two fermentations go on together. I stated, when speaking e l the spontaneous decomposition of wheaten dough, that an acid state preceded that in which it became an alcoholic ferment; and if in this condition it be mixed with a dilute solution of common sugar, and the whole kept warm for several days, it furnishes a sour liquid which is rich in lactic acid, and from which white crystalized lactate of zinc is easily prepared. There is a tendency in the liquid~o run into the alcoholic fermentation, and to produce vinegar by a subsequent change, but still the quantity ot lactic acid so formed is very considerable. Common wheat-gluten then in its mode of decomposition strikingly resembles diastase ; like that substance it runs in succession through two different dynamic conditions ; it is successively a lactic acid, and an alcohol ferment ;. is it too much to expect that it might, by proper means, be detected in a third condition, namely, as a "sugar ferment," like diastase itself in the state in which it exists in malt ? Is it not possible that diastase, as a definite proximate principle, has no more existence than yeast ; that its powers are purely dynamic, and that it is, in short, nothing more than the gluten of the seed in one of its earliest stages of decomposition ? This is an interesting inquiry, but its prosecution will be somewhat difficult, from the rapidity with which these changes succeed each other; it must be remembered that no one has yet succeeded in getting diastase ia a state fit for analysis. "Mere. Lond. Chem. Soc,
Description of an Improved Gothic Window-Blind. .By Mrs. J~.MI~A GOODE. The ordinary method of fixing blinds for the upper parts of Gothic windows~ is to attach the material of which the blind is composed~ to VoL VII, 3an Sxutss.
No. 4,~APR1L, 1844.
24.
278
Mechanics, Physics, and Chemislry.
a frame of wood of the required form, which frame is fixed to that part of the window by screws, or otherwise. The principal inconvenience of this plan is that, when not required to shade the sun, the blind cannot be drawn up, but remains fixed, and thus darkens the apartment ia which it is used.
D
H
J
In order to obviate this defect, Mrs. Goode proposes to fix the roller A B, to which the holland, or other material, C C, is attached, across that part of the window where the contraction of the frame begins, the holland, or other material, being cut into the required shape, and the broad part being fixed to the roller A A. By attaching a line D, to the pointed end of the blind, and passing it over the pulleys G I-I I, fixed in the upper, or curved, portion of the frame, and thence round the pulley J, towards the bottom of the frame, and returning it to the roller to which it is secured, the blind is readily pulled up, or down. To keep the blind in shape, wire stretchers may be sewn in across the holland, or other material, used for the purpose. The blind described above is the simplest of the two patterns sent. Trans. Soc. Arts &c.
Description of an Improved Life-Bi~oy. By Com. BEADO~, R. 2/. Fig. 1, shows the buoy as it would appear when afloat. Fig. 2, a longitudinal section of part of the main float ; and fig. 3, .the mode of suspending the buoy at the stern of the vessel, and of letting it go when required. The buoy is a cylindrical tube A A, made either of copper, or