Contributions towards the history of caproic and œnanthylic acids / by J.S. Brazier and G. Grossleth.

  • Brazier, James S. (James Smith)
Date:
[1851?]
Catalogue details

Licence: Public Domain Mark

Credit: Contributions towards the history of caproic and œnanthylic acids / by J.S. Brazier and G. Grossleth. Source: Wellcome Collection.

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    an oily acid, which by analysis was proved to be caproic acid. When it was separated by distillation, dissolved in ammonia and converted into a silver-salt 0-2814 grms. of silver-salt gave: 0*1408 „ silver = 48*65 per cent, of silver. The formula, ^12 -^n O4, requires 48'43 per cent. Caproate of amyl has a very disagreeable smell and pungent taste, is perfectly insoluble in water, of a lower specific gravity, but soluble in every proportion of alcohol and ether. The formation of caproate of amyl under the adduced circum¬ stances, appeared at the first glance rather enigmatical. We soon found, however, that fusel-oil is soluble to a certain extent in a solu¬ tion of caproate of potassa. The separation of caproic acid by sul¬ phuric acid in the presence of amyl-alcohol could not fail to produce a certain quantity of the compound ether in question. ACTION OF HEAT UPON CAPROATE OF BARYTA. The members of the series Cn Hn 04, when subjected to the action of heat, split, as is well known, into water, carbonic acid, and a new class of bodies known under the name of acetones or ketones, accord¬ ing to the following equation :— Cn Ha 04 = HO + C02 + C(Q_1) H(n_]) 0. This metamorphosis is generally effected by the distillation of the lime- or baryta-salts, in which case the carbon becomes fixed in the form of carbonate. In preparing the ketone of caproic acid, we availed ourselves of the baryta-salt. This salt is easily prepared by means of carbonate of baryta and caproic acid ; it is very soluble in water. The solution, when left to evaporate in vacuo over sulphuric acid, deposits crystalline plates. By ebullition, the odour of caproic acid becomes perceptible, and a white mass separates, which can be dried without decomposition at a temperature a little above 100° C. The dry mass evidently a somewhat basic salt, is brittle and may be easily powdered; for the distillation of the salt we employed small quantities at a time. At a gentle heat, the salt fuses without charring in the least, nearly white carbonate of baryta remaining behind ; nevertheless, only a com¬ paratively small quantity of liquid product is obtained as distillate. Experiment showed at once that the action by no means consists exclusively in a separation of carbonic acid; for during the whole process a permanent inflammable gas was evolved, the quantity of