1819.] with Bases and indifferent Substances. 45 



This decomposition, indicated by the evolution of the black 

 colour, commences by a gentle evaporation in the upper part of 

 the vessel, as soon as some salt has made its appearance in that 

 place. If, in the first part of the process, an addition of chalk 

 be not employed, a complete decomposition takes place, and the 

 liquid, which did not at first indicate the presence of a trace of 

 oinothionic acid, now contains a great excess of it. This protoi- 

 nothionic acid, which is easily separated from its combination 

 with lime or barytes by means of sulphuric acid, contains within 

 itself the whole mystery of the formation of ether ; for it gives 

 out sulphuric ether. Many chemists maintain that sulphuric 

 acid by its action on alcohol loses nothing of its capacity of 

 saturation. They draw their conclusions probably from the 

 acidity of the mixture before and after the distillation ; but the 

 result tvould turn out otherwise if the acid were examined before 

 it has united with the alcohol. 



Almost all organic bodies and the strong acids exhibit the 

 very same phenomena as we have just described. Accordingly as 

 we employ subhydrated or hydrated acids, we obtain either 

 perfect or imperfect acids. Whether the alcoholic acids be in 

 this predicament, I do not know. From the oinothionic acids, I 

 presume the contrary. 



The great extent of the set of bodies on which my observa- 

 tions have been made has hitherto prevented me from entering 

 into minute details, and has confined me to trials upon consider- 

 able masses of matter. Some interesting observations might have 

 been made on this subject. It would have been curious to know 

 how dry sulphuric acid would act when mixed with absolute 

 alcohol, and whether, as is highly probable, together with 

 protoinothionic acid, there be formed at the same time a quantity 

 of common hydrous sulphuric acid. I suppose that the water 

 separated from one portion of the acid by the alcohol unites 

 itself to another portion of the acid, and forms the common 

 hydrate of sulphuric acid. This becomes still more probable 

 when we consider that a mixture of very concentrated sulphuric 

 acid and absolute alcohol in which there was a great excess of 

 the latter still acted as sulphuric acid. 



Deutoinothionic Acid. 



The residue, after the distillation of ether, which has been 

 several times treated with alcohol and completely freed from 

 ether, but still fresh, and not black or decomposed, is to be satu- 

 rated with chalk, and treated as before directed. The deutoino- 

 thionate of lime thus obtained has a very sweet taste, and 

 possesses the peculiar property, when exposed to the air, of 

 absorbing oxygen and being decomposed into a great deal of 

 concentrated sulphuric acid and tntoinothionic acid. Henc« 

 we see the reason why the residua from the preparation of ether, 



