268 DR. ROBERTS ON THE DIURNAL 
TABLE XVII. shows the reaction of the urine at the time of 
greatest depression after breakfast and dinner on mixed food 
(twenty days breakfast and nineteen days dinner); vegetable 
food (eight days breakfast and nine days dinner); and 
animal food (eight days breakfast and dinner ). 
Mixed diet Vegetable diet Animal diet 
Alk. | Neut.| Acid || Alk. | Neut.) Acid || . | Neut-) Acid 
2 3 
OO 
Alk 
Breakfast} 12 | 2 6 2 1 5 3 
Dinner...| 17 2 0 3 0 6 8 
Out of seventy-two meals the urine became alkaline 
after forty-five, neutral after seven, and sustained its acid- 
ity after twenty. After thirty-six breakfasts the urine 
became alkaline seventeen times, neutral five times, and 
remained acid fourteen times. After thirty-six dinners 
the urine became alkaline twenty-eight times, neutral 
twice, and it continued acid six times. 
The effect of dinner is thus seen to be very considerably 
greater than that of breakfast. Indeed after a dinner of 
mixed or animal food the urine never failed to sink to the 
neutral line, its acidity being preserved only with vege- 
table food. The cause of the distinction lay, probably, 
simply in the fact, that breakfast was a much lighter meal 
than dinner, and its impression on the system conse- 
quently smaller. 
But although the urine preserved its acidity frequently 
after breakfast, and sometimes even after dinner, there 
was a notable falling off in the intensity of its reaction, 
whether regard be had to the degree of acidity per 1000 
parts, or the quantity discharged per hour. In one set of 
experiments only, namely the first on vegetable food, does 
this appear at first sight somewhat doubtful, and seem to 
require some additional explanation. The decline in the 
hourly discharge of acid after breakfast, as seen in Table 
TX., seems so small that a doubt might be cast on its 
reality ; but if we compute the hourly separation of acid 
as it stands related to the hourly discharge of solids, we 
