276 I. Remsen on“ Parasulphobenzoie Acid. 
the reaction and the satisfactory character of the results lead me 
to desire the further application of the principle involved, and 
I shall take the first opportunity to prepare a pure sulphoxylenie 
and sulphosmesitylenic acid with the object of subjecting them 
to the influence of oxidizing agents, hoping thus to obtain an 
oxybibasic and an oxytribasie acid. 
After having gained the necessary preliminary knowledge, 
I proceeded to determine the best conditions for the reaction. 
rge number of experiments were made, and as the result I 
would give the following directions: Instead of first preparing 
the potassium salts of the sulphotoluenic acids, I employed a 
solution of the acids in sulphuric acid, considerable labor being 
thus saved. 25 grams of pure toluene are dissolved in 200 grams 
of fuming sulphuric acid without the aid of heat. When this 
solution has cooled down somewhat, two volumes of water are 
added and the height of the liquid in the flask marked. Now 
end of the operation, which sony usually about twenty 
breaks. This is occasioned by the fact that the potassium 
bichromate lies at the bottom of the flask ; and that the oxida- 
tion commences and goes on rapidly just at the spot where the 
heat from the flame is strongest. This spot immediately 
becomes very hot before the remainder of the glass has been at 
all heated, and from this spot a circular piece of glass inevitably 
drops, followed by the contents of the flask. When the opera- 
tion is at an end, which, as stated, is indicated by the cessation 
of the evolution of gas, the whole is diluted with water, and 
then treated successively, as above described, with chalk, 
baryta-water, sulphuric acid and alcohol. By this method in 
the course of a few days a very large quantity of pure acid 
barium parasulphobenzoate can be p 
