402 
DR. BENCE JONES ON THE OXIDATION OF 
At 11'* 45*" A. M. 5^ ounces. Both the indigo and starch test g'ave proof of nitric 
acid. 
At 2^* 45'" p.M. 4 ounces, in which nitric acid was proved to be present by both 
tests. 
At 6'* 10*" p.M. 6^ ounces. The indigo test gave no proof. The starch test gave it 
readily. 
At 12'* 25*" p.M. 10 ounces. Still the starch test showed a trace of nitric acid. 
At 7*’ 40*" A.M. 14 ounces. Still the slightest trace by starch test. 
Comparing this with the previous experiment, it appears that exercise after the 
carbonate of ammonia causes the nitric acid to appear in the urine more quickly and 
to pass out more rapidly. With perfect rest, after twenty-four hours a trace of 
nitric acid was perceptible. With active exercise, after eight hours it ceased to be 
detected. 
Further experiments were then made to determine what was the smallest quantity 
of carbonate of ammonia that could cause nitric acid to appear in the urine. 
(7.) At 1 p.M. 20 grs. of carbonate of ammonia were taken in 6 ounces of distilled 
water. Moderate exercise was taken until 6 p.m., when 8 ounces of urine were passed. 
In this nitric acid was detected by the indigo and starch tests. 
At 11 P.M. 7 ounces of urine gave nitric acid by both tests. Urine secreted from 
10’* 30*" P.M. the following night to 7 *' 30*" a.m. the next morning, about 24 ounces, gave 
no proof of nitric acid by the indigo test, but gave a trace with the starch test. 
Still smaller quantities of carbonate of ammonia were taken. 
(8.) At 12'* 30'" A.M. about 7 ounces gave no evidence of nitric acid by the indigo 
or starch test. At this time 5 grs. of carbonate of ammonia were taken in an ounce 
and a half of water. 
At 5'* 55*" P.M. 7i ounces gave no proof of nitric acid by the indigo test ; slight 
evidence by starch. 
At 12'* 10'" P.M. 15 ounces; slightest evidence by starch. 
At 7’^ 40'** A.M. 15 ounces; the same. 
(9.) At 12'* 20"* A.M. 12 ounces; doubtful evidence of nitric acid. At this hour 
10 grs. of carbonate of ammonia were taken in 2^ ounces of distilled water. 
At O'* 50'" P.M. 9 ounces ; gave proof of nitric acid by the indigo and starch tests. 
At 12'* 20'" P.M. 15 ounces; indigo gave no proof; starch decided proof. 
At 7'* 30*" A.M. 17 ounces; no decided evidence. 
Hence it appears that 10 grs. of carbonate of ammonia was the smallest quantity 
that gave decided evidence of nitric acid by both tests. In the course of ten days, in 
all, 155 grs. of carbonate of ammonia were taken. 
(10.) After this quantity of carbonate of ammonia, the water passed at 7^ 30"* a.m., 
as I have said, gave no decided evidence. 
At 12'* 25'" A.M. 12 ounces of urine gave decided evidence with starch ; none with 
indigo. 
