280 Royal Society : — 



Disulphometholic acid Cj H_j 4 SO3. 



Disulphetholic acid ^4 ^6 ^SOg. 



Disulphopropiolic acid C^ Hg4S0.j. 



Disulphobenzolic acid 0,2 Hg 4SO3. 



Au acid of analogous composition exists in the naphthaline-series, 

 disulphonaphthohc acid, Cj^ 11,^4803, which was discovered by Bcr- 

 zelius, and subsequently studied by Laurent. Many of these sub- 

 stances may be actually obtained directly from the hydrocarbons by 

 the action of sulphuric acid. 



On the other hand, chemists are well acquainted with the deport- 

 ment of olefiant gas under the influence of anhydrous sulphuric acid. 

 The crystalline compound discovered by Magnus, and described by 

 him under the name of sulphate of carbyle, whatever its constitution 

 may be, can be considered as a direct combination of olefiant gas, 

 with four equivalents of anhydrous sulphuric acid, — 



Sulphate of carbyle C^ H^ 4SO3. 



It can scarcely be doubted that all the other hydrocarbons, 

 C«2 H„2j propylene, butylene, amylene, &c., will furnish homologous 

 substances. 



Sulphate of carbyle, when submitted to the action of water, assimi- 

 lates two equivalents, and is converted into a bibasic acid (ethionic), 

 C4H4 4S03-1-2HO = C4Hr02 4S03, which accordingly may be 

 viewed as an association of alcohol with four equivalents of anhy- 

 drous sulphuric acid. Terms analogous to ethionic acid are sure to 

 be found when the study of the homologues of sulphate of carbyle 

 shall be taken up by chemists. 



The production of disulpho-compounds of perfectly similar com- 

 position, from substances belonging to such different groups of bodies, 

 as the hydrocarbons homologous and analogous to marsh-gas, ethy- 

 lene and alcohol, suggested the possibility that the substances in ques- 

 tion might be but individual examples illustrating a far more general 

 mode of formation. It became, in fact, probable that all organic 

 bodies capable of uniting with the elements of two equivalents of 

 anhydrous sulphuric acid might, under favourable circumstances, be 

 induced to assimilate two additional equivalents of anhydrous sul- 

 phuric acid, and thus furnish other terms belonging to the class of 

 disulpho-compounds. 



The only additional class of compounds to which we have as yet 

 successfully extended our labours, is the group of organic bases. 



Action of Sulphuric Acid upon Aniline. 



The first product which sulphuric acid forms with aniline is 

 simply the sulphate of the base. 



A further addition of acid, assisted by heat, dissolves the sulphate, 

 and after a suflSciently long digestion, the whole is converted into 

 sulphanilic acid. If too high a temperature be employed, the acid 

 becomes very dark in colour ; and indeed there is a limit beyond 

 which carbon is rapidly deposited, accompanied by the evolution of 

 abundance of sulphuric acid. 



