433 Of the Action of Vegetalle Acids on Alcohol. 



the three preceding mineral acids, an ether which is easily 

 decomposed by potash, and which contains acetic acid. 



2d. That the benzoic acid and alcohol produce with the 

 muriatic acid a kind of oil heavier than water, which may, 

 like the acetic ether, be decomposed by potash, and which 

 has the benzoic acid for one of its principal ingredients. 



3d. Lastly, that he obtained no particular product by 

 treating the tartaric, citric, or succinic acid, dissolved in 

 alcohol, with either the sulphuric, nitric, or muriatic acid. 

 Thus it was known to Scheele that the acetic ether con- 

 tains acetic acid, and that the oil of benzoin contains ben- 

 zoic acid ; but he was not acquainted with the other prin- 

 ciples of which they are compu:;ed, nor did he understand 

 the action of alcohol and the mineral acids in the for- 

 mation of these compound species. From that alone we 

 may conceive that, had he drawn some conclusions from 

 his experiments relative to the formation of these com- 

 pounds, he would have admitted in the acetic ether and oil 

 of benzoin, a vegetable acid, as well as the mineral acid 

 and alcoliol employed, or have considered them only as 

 new bodies derived from the alcohol decomposed by the 

 mineral acid ; or as new bodies and the mineral acid itself. 

 This triple hypothesis is sufficient proof that the experi- 

 ments which gave birth to it arc incomplete ; it was ne- 

 cessary therefore to repeat them, which I have done with 

 so much the less trouble, as they are immediately connected 

 with those experiments I have been engaged in upon ethers, 

 which not only presented me with very singular results, 

 but also promise to be of great importance. 



In the division of my researches I have followed the ex- 

 ample of Scheele, examining in succession the action of 

 the pure vegetable acids on good rectified alcohol, and of 

 the same acids mixed with the mineral ones. 



Almost all the vegetable acids dissolve in alcohol, and 

 separate again fiom it by distillation, without affording any' 

 parlicnla.r"rc.-;ull.-, hovtevcr often tiie same -portion of al- 

 cohol is distilled from the same portion of acid: this I 

 know to be the case with the tartaric, citric, malic, ben- 

 zoic, oxalic, and gallic acids ; and I have not the least 

 doubt, ahlioi.gh I have nut made the experiments, but that 

 the suberic, succinic, nmcic, pyro-tartaric, moric, and 

 honi'^stic acicl, are in this respect similar. But it is very, 

 different with the acetic acid. Its action upon alcohol is 

 such, that by means of many distillations both bodies dis- 

 appear and form a true ether : hence I conclude, that this 

 probably is the only one, of all the vegetable acids hitherto 



known. 



