272 ANNUAL OF SCIENTIFIC DISCOVERY. 



potato fusel oil, distilling at fii-st, still contains some alcohol, and the re- 

 ceiver is therefore changed as soon as the temperature in the retort has 

 risen to 208, when it remains stationary. This part of the distillate is the 

 pure amylic alcohol. 



It may also be obtained sufficiently pure for all purposes, if the crude oil 

 is at once distilled over a slow fire, and the receiver changed when the tem- 

 perature has attained 298; a rectification of this product is necessary, and 

 the first portion of all the distillates may be preserved for future use, when 

 it may be added to other portions of crude fusel oil. 



Fusel oil, thus purified, is a thin, oily liquid, crystallizing at 3 F. It has 

 a penetrating, disagreeable odor, and a hot, acrid taste. The inhalation of 

 its vapor and its internal administration are poisonous, producing coughing, 

 nausea, vomiting, vertigo, fainting, prostration of the lower extremities, 

 convulsions, asphyxia, and death. Ammonia has been recommended to 

 counteract these deleterious effects. 



It is not used in medicine, but has attained considerable importance in 

 the arts, chiefly for the artificial production of perfume and fruit essences, 

 and by oxidizing agents for the preparation of valerianic acid. 



Jargonelle Pear Oil is an alcoholic solution of acetate of oxide of amyle, 

 which may be obtained by digesting fusel oil with strong acetic acid for 

 several days, but more satisfactorily by the following process : one part of 

 fusel oil, two parts of acetate of potassa, and one part of sulphuric acid, 

 are mixed and distilled. The distillate is washed with a weak solution of 

 potassa, then dried by chloride of calcium, and rectified over oxide of lead 

 to abstract the last quantities of free acetic acid. This ether is a light, vol- 

 atile liquid, boiling at about 270. Its constitution is expressed by CioAnO, 



C4HSQ3. 



Bergamol Pear Oil is similar to the former: five parts of acetate of oxide 

 of amyle mixed with one and one-half parts of acetic ether, are dissolved in 

 from one hundred to one hundred and twenty parts of alcohol. 



Apple Oil. In the preparation of valerianic acid from fusel oil, the dis- 

 tillate sepai-ates into two layers, the upper stratum of which is an oily 

 liquid, consisting principally of valerianate of oxide of amyle. It is Avashed 

 with a weak solution of carbonate of soda, then with water, afterwards 

 dried with chloride of calcium, and distilled, preserving that portion which 

 comes over at 270 to 274; it consists of CioHnO, CioHgOs. One part of 

 this ether dissolved in six or eight parts of alcohol, furnishes apple oil. 



Oil of Pineapples. For the preparation of this essence, the making of 

 butyric acid is necessary. As obtained by the saponification of butter, 

 some difficulties are presented in freeing it of caprylic, caprinic, and vac- 

 cinic acids ; it is therefore best to prepare it artificially by butyric fermenta- 

 tion, for which purpose, one hundred parts of starch sugar, or cane or milk 

 sugar, are dissolved in water, and set aside' in a warm place, with ten parts 

 of old cheese; or a mixture of one hundred parts of sugar, one hundred 

 and fifty parts milk, and fifty parts of powdered chalk, are allowed to 

 ferment in a warm place; if diluted with water, fermentation takes place 

 quicker. After the cessation of the evolution of gas, the liquid, on evapo- 

 ration, furnishes butyrate of lime, ten parts of which are to be dissolved in 

 forty parts of water, and distilled with three or four parts of muriatic acid; 

 from the distillate the acid is separated by saturating it with chloride of 

 calcium, the oily liquid is rectified, and that portion coming over at 327 is 

 preserved as pure concentrated butyric acid. 



