txperiences in acilng upon Akoliol. 365 



The purest siilphovinate of barytes subjected to the action of 

 heat is very easily decomposed, even by a slight evaporation, to 

 dryness. Its products are an inflammable gas which burns like 

 defiant gas, sulphurous acid, very little carbonic acid, water, 

 and an ethereal oil, the odour of which mixed with that of sul- ' 

 phurous acid, has much resemblance to that of acetic ether. It 

 is not improbable that this ether might be formed ; but we made 

 our experiments on too minute quantities to obtain the certainty 

 of it. There remained in the apparatus sulphate of barytes, 

 blackened by a very small quantity of charcoal, which a short 

 exposure in the air to a red heat sufficed to purify completely. 



The analysis of sulphovinate of barytes not having been yet 

 made, and M. Vogel having contented himself with remarking 

 the analogy which exists between sulphovinous acid and hypo- 

 sulphuric acid, it appeared to us interesting to inquire v/hether 

 the composition of the first of these acids, abstracting the vege- 

 table matter, was the same as that of the second, and in what the 

 manner vegetable matter influences its capacity of saturation. 



One hundred parts of snlphovinate of barytes dried in the air 

 lost 45'07, and furnished 5'J-9.3 sulphate of barytes very white 

 and very pure. One hundred other parts of the same salt, cal- 

 cined with a mixture of chlorate and carbonate of potash, and 

 afterwards precipitated by chlornret of barium, produced 111*47 

 of sulphate of barytes, being nearly double 54'93. 



By thus abstracting the vegetable matter the sulphovinous 

 acid appears composed in the same manner as hypo-sulphuric 

 acid, and its capacity of saturation is not changed by the pre- 

 sence of this vegetable matter, which seems to play there the same 

 part as water of crystallization. 



Nevertheless the vegetable matter gives to the sulphovinates 

 particular characters. That of barytes has a crystallization dif- 

 ferent from that of the hypo-sulphate, and it loses 45 07 by the 

 calcination, while the latter loses only 29'9. The other salts 

 formed by sulphovinous acid and hypo-sulphuric acid appear 

 equally different, and merit particular attention. M. Dabit thinks 

 that the vegetable matter was accidental in the sulphovinates; 

 but as it is on the contrary essential to them, the proofs which 

 he has offered to demonstrate the existence of an acid more oxy- 

 genated than sulphurous acid, and less so than sulphuric acid, 

 cannot now be regarded ; for the decomposition of nitric acid by 

 the sul|)hovinate of barytes which he had observed, and even the 

 direct absorption of oxygen gas by this salt, which besides has 

 not been confirmed, may be attributed to the vegetable matter 

 itself. 



Agreeably to the observations which have been made, and by 

 ourselves in i)articular, wc admit that the greater part of the ve- 



{^ctable 



