116 L. Remsen on Parasulphotoluenic Acid. 
an assertion made in a brief notice as to one made in a long arti- 
cle, and I shall continue to do so hereafter, whatever deviation 
from this principle the custom of a few chemists may appear to 
sanction. 
In view of the importance of the question under discussion, 
I have endeavored to furnish further proofs of the value of 
Meyer’s reaction, by employing it for the purpose of effecting 
new conversions of known compounds into known compounds 
the constitutions of which are established. Of one of these con- 
until it became almost black. Toward the end of the opera- 
tion, inflammable gases escaped and took fire at the top of the 
erucible. The whole was now allowed to cool and then treated 
with water. With the exception of a small black residue, the 
mixture dissolved entirely, forming a clear solution. This was 
treated with sulphuric acid until it showed an acid reaction; 
reprecipitated. Its fusing point was again found to be . 
ese properties suffice to characterize the substance as para 
toluic acid ; but another and more positive proof of its nature 
was given. The acid was treated with the ordinary oxidizing 
mixture of potassic dichromate, sulphuric acid and water, and, 
after boiling for a short time, an insoluble powder was throw? 
down. This was filtered off, washed and diried, and was then 
found to have all the properties of terephtalic acid. It was ™ 
soluble in water, hot as well as cold, and did not fuse, but sub- 
limed in a capillary tube before an applied flame. 
Now as parasulphotoluenic acid is known to yield a cresole, 
which in turn yields paraoxybenzoic acid, and as paraoxybet 
zoic and paratoluic acids are conceded to belong to the same 
series, it follows that, in the instance here considered, the sul- s 
pho-group is replaced directly by carboxyl. But, further, pare 
