6 CONVERSION OF BENZOIC INTO HIPPURIC ACID. 
ART. IV.— ON THE CONVERSION OF BENZOIC INTO HIP- 
PURIC ACID. 
BY JAMES C. BOOTH AND MARTIN H. BOTE, M.D. 
{From the Transactions of the American Philosophical Society.) 
The importance of the application of chemical principles 
to the various processes in the animal economy, not less 
than their interesting character in a scientific point of view, 
having led us to undertake a few experiments on a singular 
fact observed some years since by Woehler, we have 
deemed them worthy of being offered to your notice on the 
present occasion, although time has failed in completing the 
series of investigations which was contemplated. I there- 
fore propose to offer you a few remarks on the " Conver- 
sion of Benzoic into Hippuric Acid," which are the results 
of the conjoint labors of Professor Booth and myself. 
Before entering into the details of the present treatise, it 
may not be out of the way to make a few remarks on some 
of the most important ingredients of urine, as far as con- 
nected with the present subject; urine contains about 
ninety-three parts of water and seven of solid substances. 
Of these seven parts of solid substances, a substance called 
urea forms three parts. About two parts are formed by in- 
organic substances, such as chlorides of potassium, sodium 
and ammonium, sulphates of soda and potassa, and the 
phosphates of lime, magnesia, soda and ammonia ; while 
the remaining two parts are mostly formed of other organic 
substances, as extractive matters, mucus of the bladder, 
some lactic acid and uric acid. 
Urea is in every respect the most remarkable substance 
in the urine, and that which imparts to it its most peculiar 
characters. It is a white crystallizable substance, and very 
soluble in water. It seems to stand on the borders between 
