162 



The question naturally suggested itself, whether the same acid 

 could not be prepared directly from the hydrocarbon benzol. 



Mitscherlich has already described an acid (the sulphobenzolic) 

 in which one equivalent of that hydrocarbon is associated with one 

 equivalent of bibasic sulphuric acid. We have proved by experiment 

 that sulphobenzolic acid takes up the elements of an additional equi- 

 valent when it is submitted to the prolonged action of Nordhausen 

 sulphuric acid, and that, in fact, the union of these two bodies pre- 

 sents the most ready method of procuring disulphobenzolic acid in a 

 state of purity. 



The preceding researches establish in two different groups of 

 bodies the existence of a series of bibasic acids containing four equi- 

 valents of sulphur, and which, irrespectively of any special view re- 

 garding their molecular arrangement, may be represented as formed 

 by the association of the hydrocarbon (corresponding to marsh-gas) 

 of the various groups with four equivalents of anhydrous sulphuric 

 acid, 



Disulphometholic acid C 2 H 4 4SO 3 . 



Disulphetholic acid C 4 H 6 4SO 3 . 



Disulphopropiolic acid. ..... C 6 H 8 4SO 3 . 



Disulphobenzolic acid C 12 H 6 4SO 3 . 



An acid of analogous composition exists in the naphthalin-series, 

 disulphonaphtholic acid, C 20 H 8 4SO 3 , which was discovered by Ber- 

 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 carbyl, whatever its constitution 

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

 with four equivalents of anhydrous sulphuric acid, 



Sulphate of carbyl . . . . C 4 H 4 4S0 3 . 



It can scarcely be doubted that all the other hydrocarbons, 

 Cn2 H n2 , propylene, butyl en e, amylene, &c., will furnish homologous 

 substances. 



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



