OF THE ACIDITY OF THE URINE. 
243 
These three days’ variations confirm those previously given ; all show the influence 
of digestion ; the constant decrease of the acidity of the urine after food was taken, 
and the gradual increase of acidity as the food is absorbed. 
The second day, before breakfast, it may be observed that the water made at 7 and 
at 8’’ 40“a.m., had very nearly the same degree of acid reaction ; that is, during the 
last hour and forty minutes before breakfast there was no increase in the acidity of 
the urine. I have previously pointed out that on two occasions there was a diminu- 
tion of the acidity of the urine just before breakfast. 
It may, perhaps, indicate that acid is sometimes separated from the blood by the 
stomach previous to the food being taken. 
A young physician with an irritable stomach, but otherwise in good health, made 
the following observations on his urine, at my request, for seven days. Breakfast 
was always immediately after the second testing of the water. 
February 20. — S'* 30™ a.m. slightly acid. 9 a m. neutral. 1 p.m. alkaline. 
February 21. — S'* 30“ a.m. strongly acid. 9 a.m. slightly acid. 12 a.m. alkaline. 4 p.m. 
slightly acid. 
February 22. — 7 a.m. slightly acid. 8** 30“ and 9 a.m. alkaline. 2 p.m. alkaline. 4 p.m. 
neutral. 5** 30™ p.m. slightly acid. 
February 23. — S'* 30“ a.m. neutral. 9 a.m. alkaline. 12'* 30“ p.m. alkaline. 2'* 30™ p.m. 
slightly acid. 
February 24. — S'* 30“ a.m. slightly acid. 9 a.m. alkaline. 1 1** 30™ a.m. alkaline. 
February 25. — S'* 30“ a.m. slightly acid. 9 a.m. neutral. 2 p.m. alkaline. 4 p.m. slightly 
acid. 
February 26. — S'* 30™ a.m. strDngly acid. 9 a.m. slightly acid. 9** 30™ a.m. alkaline. 
Thus, just before breakfast, the urine was neutral twice, and alkaline thrice, in 
seven experiments. 
In the previous experiments, after honey had been taken for breakfast, the acidity 
was seen not to diminish immediately after dinner ; and the same thing happened 
the second day after sulphuric acid was taken; at 5** 30“ p.m., immediately before 
dinner, the acidity was 20‘50 measures ; nearly two hours afterwards, at 7*’ 10“ p.m., 
the acidity had increased to 24*26. At lO** 30™ p.m. it had diminished to 6’77- The 
third day, with the same quantity of sulphuric acid, no increase in the acidity, two 
hours after food, was observed. 
As no positive proof was obtained of the influence of sulphuric acid on the acidity 
of the urine by examining the water passed at different hours, I next endeavoured to 
determine whether this acid produced any effect on the total amount of acidity of 
the urine in twenty-four hours. 
It was necessary for the purpose of comparison, that the total acidity of the urine 
in twenty-four hours, when sulphuric acid was not taken, should be first known. 
The breakfast and dinner were of meat and bread, coffee, wine and water; the same 
for the six days. 
