I. Remsen on Parasulphobenzoic Acid. 281 
mate). By this means the thihydrobenzoic acid (?) was s 
changed in character as to become soluble, whereas the other 
constituent of the mixture was left behind in a pure condition 
unacted upon. It was dissolyed in ammonia, bil id co by 
means of a strong acid, filtered and well washed out. In this 
condition it had the form of a ver light, floceulent, whit 
mass. It could be dissolved in boiling alcohol, and from this 
solution it was obtained in the form of microscopic needles which 
were deposited upon the sides of the vessel. is substance 
barium salt of the acid was, however, thus obtained, and this 
was very difficultly soluble in water and did not crystallize. 
The calcium salt resembled this in eve way. 
These are the properties of terephtalic acid, with the excep- 
tion of the conduct toward alcohol, To this I am not inclined 
to attach much weight, as the acid which is described as insoluble 
m alcohol is that which is obtained by oxidation of xylene, and 
the condition of this acid differs essentially from that of the light 
mass obtained by precipitating it from one of its salts. Further, 
I found that after being dried, the acid, as obtained by me, was 
also insoluble in aleohol. I would hence rather consider this 
conduct as indicating a property of terephtalic acid which had 
been overlooked. The substance was proved to have the com- 
position of terephtalic acid by the following analysis: 
0°2325 grams substance, dried over sulphuric acid, gave 0°4897 
ms CO? = 013355 grams C and 0°0832 grams H 
0°00924 grams H. 
Calculated. Found. 
Ce 96 57°83 57°44 
He 6 3°61 3°97 
O04 64 38°56 
166 100-00 
The proofs that terephtalic acid is formed when potassium 
Parasulphobenzoate and sodium formate are fused together are 
thus conclusive. It remained, however, to show that neither 
phtalic nor isophtalic acid was formed at the same time. The 
crude product was boiled with water for a long time and a 
filtered. off. On allowing the filtrate to cool a small quantity o 
substance was deposited in the form of powder. The whole was 
shaken with ether, which dissolved the powder and poe 00 
Whatever might be in solution. The original solution 
