474 MR. G. B. BUCKTON AND DR. A. W. HOFMANN’S RESEARCHES ON THE 
are present in the usual sulpho-acids. Sulphanilic acid, C,2 N S2 Oe, may be viewed 
as formed by the association of one equivalent of aniline and two equivalents of an- 
hydrous sulphuric acid. 
We were curious to ascertain whether this acid, by assimilating once more the 
elements of anhydrous sulphuric acid, was capable of becoming disulphanilic acid, 
C,2H7NS4 0.2. 
The existence of disulphobenzolic acid, C12H6 840,3, the barium-salt of which we 
have described in the preceding pages, together with the formation of an interesting 
acid lately obtained by M. Kilkenkamp* in the reaction of sulphite of ammonium 
on dinitrobenzol, appeared to leave no doubt regarding the existence of a disulph- 
anilic acid. In fact, M. Kilkenkamp’s dithiobenzic acid, C12H8N2S4OJ2, is most inti- 
mately connected with the acid we were in search of, as is obvious by a glance at the 
following Table, in which we have placed a number of known substances in juxta- 
position with bodies, ideal at present, but the existence of which can no longer be 
doubted. ‘ 
Hydrocarbons and substitutes. 
C12 Hs 
Benzol. 
Sulpho-acids and substitutes. 
C]2 He 82 Og 
Sulphobenzolic acid. 
Disulpho-acids and substitutes. 
Cj2 Hg 84 0,2 
Disulphobenzolic acid. 
Nitrobenzol. 
c„{ 
Nitrosulphobenzolic acid. 
Phenylamine. 
Aniline. 
Phenylsulphamic acid. 
Sulphanilic acid. 
Phenyldisulphamic acid. 
Disulphanilic acid. 
f 
1 
H4^ 
rH4. 
CJN04 
C,2 
NO4 82 0g 
C.2 NO, 840,2 
IN04J 
1 
.NO4J 
INO4J 
Dinitrobenzol. 
rH4. 
rH4. 
f 
C,2 NH2 
NH2 82 0g 
C, NH2 840,2 
INH2J 
INH2J 
TNH2J 
Phenyldiamine. 
(Semaniline ?) 
Dithiobenzic acid. 
Phenyldisulpho-diamic acid. 
The preceding synopsis, whilst it fixes, we believe, the correct position of dithio- 
benzic acid in the benzol-series, exhibits at the same time its close relation to the 
disulphanilic acid which we endeavoured to produce, and the formation of which, it 
may at once be stated, succeeded without much difficulty. 
* Annalen der Chemie und Pharmacie, Neue Reihe, B. xix. S. 86. 
