280 I. Remsen on Parasulphobenzore Acid. 
salt was fused with an equal weight of pure sodium formate. 
In order to bring the mass to the point of fusion a compar- 
atively high temperature was required. It then remained in a 
semi-liquid condition, apparently evolving gas for a short time, 
finally becoming much darker in color—in fact nearly black. 
t a certain point volatile products, evidently containing 
sulphur, were given off, the.odor of which was intensely dis- 
agreeable. The operation was performed in a silver crucible; 
and the mass constantly stirred with asilver spatula. Occasion- 
ally the vapors which were given off took fire above the cruci- 
ble, and, on the gas-flame being now removed from beneath, 
and the flame of the burning vapor being extinguished, the 
mixture continued red-hot for a short time, presenting the 
appearance of a burning coal. When all had cooled down to 
the ordinary temperature the crucible and contents were placed 
in water, and this boiled. The solution thus obtained was 
reaction of Meyer for the preparation of isophtalic acid. The 
amount of the substance obtained was not sufficient to permit 
of its close examination, its perfect separation from the other 
substance formed being impossible. The difficulty of separa- 
tion threatened at the outset to be a serious obstacle in the way 
of deciding the point under consideration. One method after 
another was tried; but the results were decidedly unsatisfac- 
tory ; until finally the mixture was subjected to the influence 
of an oxidizing agent (sulphuric acid and potassium bichro- 
* Ador, Berliner Berichte, [V Jahrgang, 622. 
