OF THE SULPHATES IN THE URINE. - 
259 
g-iven of an increase in the amount of sulphates in consequence of sulphate of magnesia 
having been taken in doses of about 2 drachms. The highest instances were — 
Spec. gr. Sulphate of baryta. 
In one case urine . . 1028’0 contained 15-89 grs. per 1000 grs. of urine. 
In another case urine . 1024-3 contained 22-55 grs. 
The conclusions from these experiments are, — 
I. That the sulphate of baryta varies soon after food from 15-23 grs. per 1000 grs. 
of urine, specific gravity 1033-9, to 9-45 grs. per 1000 grs. of urine, specific gravity 
1029-3. It varies long after food from 8-56 grs. per 1000 grs. of urine, specific gravity 
1027 - 6 , to 7‘07 grs. per 1000 grs. of urine, specific gravity 1025-3. 
II. As to the causes of variation — (a) as regards food ; {b) as regards exercise. 
{a) Food, whether animal or vegetable, causes an increase in the quantity of sul- 
phate of baryta precipitated, but the difference between animal and vegetable food is 
not well-marked. 
{b) Exercise appears slightly to increase the amount of sulphates in the urine, but 
the increase is not so marked as it is after food. 
III. As to the effect of medicines on the sulphates, — (a) sulphuric acid ; {b) sul- 
phur; (c) sulphates. 
{a) Thirteen drops of strong sulphuric acid in one of three experiments increased 
the sulphates in the urine. Twenty drops of the same acid gave no positive proof. 
Seventeen drachms of dilute sulphuric acid, taken in eight days, gave no positive 
proof of an increase of sulphates in the urine on the ninth day. 
But when the whole quantity of urine passed in twenty-four hours for three suc- 
cessive days, when no sulphuric acid had been taken, was compared with the whole 
quantity passed in twenty-four hours, when half an ounce of dilute sulphuric acid 
was taken, then for three successive days that the experiment was made, the increase 
of sulphates was most marked. And from this it is certain, that when a large quan- 
tity of dilute sulphuric acid is taken the sulphates are increased in the urine. When 
small quantities of sulphuric acid are taken the effect on the sulphates in the urine 
is not detectable. 
{b) 61 J grains of dry sulphur, taken for five days, gave an average amount of sul- 
phates in the urine, both before and after food, higher than when no sulphur was 
taken. But with this dose the increase, though decided, was not considerable. 
(c) 123^ grains of sulphate of potash produced a marked increase from two to 
four hours afterwards. In seven hours the increase was more marked. Sulphate 
of magnesia had a similar effect. The increase in the sulphates in the urine was 
much more evident than when sulphur or sulphuric acid were taken. 
The result of these experiments is — 
1st. That the sulphates in the urine are much increased by food, whether it be 
vegetable or animal. 
