390 Formathn' of Ethtr. 



fulphuric acid, there is formed, at tKc expence' of fliC n;in, water, vep;etable acid, and am- 

 moniac, while carbonc ia precipitated, and a complete lieilruc^ion of the burned parts is tht 

 refult of thefe fimultaiicous effetls, as appears by the brown or black fear which afterwards 

 falls off, and is feparatod as a foreign body. Hence may be deduced how great tlie diforganiz- 

 ing power of this concentrated acid niuft be on the coats of the (lomach or the ocfophagus, 

 «nd the utility of prefenting to it, at the moment it is fwallowed, a mucous liquid fub- 

 {lancc, on which its aclion may be dirciSily and fpeedily exercifcd. 



From the whole of what is here ftateJ concerning the reciprocal aflion of concentrated 

 fulphuric acid, and the ternary or quaternary compounds which belong to the vegetable and 

 animal kingdoms, wc may perceive that its tendency to dellroy thefe complicated compo- 

 fitions, and convert them into others more fimple, mud open a new path in the vegetable 

 analyfis. We may perceive that, fince itsefleils are confined to thofe here defcribed, while 

 the fubftances and the fulphuric acid are permitted to a£V fpontaneoufly and without foreign 

 aflfiilance, the energy of the acid will proceed much further in this decompofition when it is 

 increafed by the addition of new quantities of this fluid, or the application of accumulated 

 heat. But the new refults thus produced would carry us from the fubjedl here treated, 

 and to which we at prefent mean to confine ourfclves. 



In this accurate defcription of the fpontaneous a£lion of fulphuric acid upon vegetable 

 and animal matters, our intention was to (hew more particularly that this knowledge may 

 have a dire£l influence upon pharmaceutic operations. Our aflbciate Vauquelin has fliewn 

 in another memoir, which forms the continuation and ufcful rtfult of the prefent, that the 

 principles here explained are alone capible of developing the theory of the formation of 

 ether, hitherto fo vague and uncertain ; and at the fame time to perfeft the operations 

 proper to aflbrd tliefe important produ£ls. This firft work, which we offer jointly to the 

 fchool of pharmacy, will be a confirmation of the truth configned in the difcourfe on the 

 indilToluble union of chemiftry and pharmacy, namely, that the former cannot make the 

 flighted advance, without the latter receiving immediately a proportional degree of perfeAion. 



Concermn" the Aclhn of the Sulphuric Acid upon Alcohol, and the Formation of Ether. 



THE preparation of ether is a complicated pharmaceutic operation, the refults of which 

 are no lefs known than the theory is obfcure. This is proved by the different explanations 

 civen by the chemifts who have treated of this operation before the eftablifliment of the 

 pneumatic do6lrine. 



The greater number of modern philofophers are in general of opinion, that the whole me- 

 chanifm of the formation of ether confifts in the decompofition of the fulphuric acid, and 

 the tranfition of part of its oxygcne to the elements of the alcohol. According to this 

 hypothefis, water, carbonic acid, and fulphureous acid are formed. This opinion contains 

 the fame error as was pointed out in the foregoing memoir. In order to explain the opera- 

 tion with perfpicuity and effctl, we fliall defcribe its cirtumftances from the beginning to 

 the end. And while we thus treat on a fubje<!l familiar to every chemift, wc hope to prove 

 that this operation, fo common, and fo often repeated, docs ncverthclefs offer, in the feries 

 of its phenomena, certain fa£ls which have not yet been properly defcribed, and of which 

 the accurate knowledge alone can afford a folid theory of etherification. 



Enperimeni 



