414 Dr. Muspratt on the Salts of Sidphurovs Acid. 



Urea, creatin, glycocoll, leucin, cystin, &c. are organic 

 bases, and only products of the animal body or its elements, 

 and organic bases are partly poisonous, partly beneficial in 

 their action. I have caused the new experiments of Mulder 

 on his protein to be repeated. The substance prepai'ed by 

 Fleitmann in this laboratory, according to his new method, 

 and supposed to be free from sulphur, still contains 1*5 per 

 cent., as does likewise a similar preparation by Laskowski. 



I beg of you to communicate this short notice to the Che- 

 mical Society, of which I have the honour to be a member. 



LXIII. On the Salts of Sulphurous Acid. 

 By J. Sheridan Muspratt, Esq., Ph.D.* 



T HAVE been induced to return to this subject by a paper 

 lately published by Dr. Rammelsberg in PoggendorfPs 

 Annalen t. In his treatise he differs slightly from me in the 

 quantities of water contained in some of the sulphites, but as 

 he invariably took his water as loss and as mine was generally 

 determined by combustion with chromate of lead, I did not 

 think it worth while going over all the analyses that 1 had 

 performed in Giessen, being so thoroughly convinced of the 

 accuracy of those results. The only point where we materially 

 disagree is regarding the constitution of the red sulphite of 

 copper, and which will be subsequently discussed under that 

 head. When I first undertook, in Baron Liebig's laboratory, 

 the investigation of the salts of sulphurous acid, very little 

 was known of their constitution ; but since that time they 

 have occupied the attention of numerous chemists, and are 

 now invested with as much interest as the compounds of any 

 other acid. They are very readily decomposed either by 

 moisture or heat, and on this account may have led different 

 chemists to the assumption of various formulae for the same 

 salt. For example, there is scarcely any salt of this acid 

 which does not contain traces of sulphate, which are always 

 overlooked in the analysis ; and moreover, unless great care 

 is exercised in oxidizing the sulphurous acid when its quantity 

 is to be determined, serious errors may arise. I shall now 

 proceed to the description of the sulphites under their re- 

 spective heads. 



Sulphite of Soda. — This salt is obtained by transmitting 

 sulphurous acid through a solution of carbonate of soda until 

 the liquid becomes acid, and then allowing the solution to 



* Communicated by the Chemical Society; having been read Dec. 21, 

 1846. 



t Ixvii. pp. 245, .'J91 ; or No. 89 of the Chemical Gazette, July I, 1846, 

 p. 254. 



