478 MR. G. B. BUCKTON AND DR. A. W. HOFMANN’S RESEARCHES ON THE 
Our experiments point out moreover the universal occurrence and the general 
mode of formation of these substances. All organic molecules, particularly in the 
nascent state, appear to be capable of assimilating the elements of either two or four 
equivalents of anhydrous acid. Tlie formation of the two groups of acids which are 
thus produced, presents a great analogy with the production of the nitro-substitutes 
generated under the influence of nitric acid. All these compounds are generated 
with elitnination of water. In the action of nitric acid and sulphuric acid upon benzol, 
for instance, we have 
Ci 2 Hg-j- HNOg 
Benzol. 
= Ci 2 H 5 N ()4 +2140. 
^ 
Nitrobenzol 
,2 i4g+2HNOe =0,2 1+ N 2 O 3 +4140. 
Dinitrobenzol. 
t ^'12 Idg+ I+SaOg — C 12 H 0 S 2 O 5 + 2 HO. 
v ) K ! 
Benzol. 
Sulphobenzolic acid. 
C, 2 14g+2I42 S 2 03=C.2 146 S 4 0,2+4H0. 
V. ) ! 
Benzol. 
"V" 
Disulphobenzolic acid. 
The analogy of these I’eactions is obvious. 
The action of nitric acid upon organic bodies is by no means limited to the produc- 
tion of nitro-compounds, corresponding to nitrobenzol and dinitrobenzol ; frequently 
additional bodies are formed with elimination of 6, 8, and in a few isolated cases, 
even of 10 equivalents of water. It is possible that analogous sulpho-compounds 
may exist ; hitherto, however, no substances have been observed in which the assimila- 
tion of sulphuric acid has gone further than in the disulpho-acids. 
Appendix. 
During the prosecution of the researches detailed in the preceding paper, our 
attention was repeatedly called to the substance which M. Liebig has described 
under the name of metldonic acid, and which he obtained in the reaction of anhydrous 
sulphuric acid upon dry ether at low temperatures*. The properties of the barium- 
salt of this most remarkable acid very closely agree with those which we observed in 
studying disulpliornetholate of barium, although both appeared different in composi- 
tion. We were repeatedly inclined to admit and to doubt the identity of the two 
substances. We have now arrived at the conclusion, that methionic and disnlpho- 
metholic acid are aetually identical. 
* Liebig, Annalen der Chemie und Pharm. xiii. 32; xxv. 39. Ann. de Chimie et de Phys. i. 59. 182. 
Wetiierell, Ann. der Chemie und Pharm. Ixvi. 122. 
