Mr. W. Brande’s Observations , &c. 137 
the urine, that in several instances where there was an 
increased formation of uric acid, magnesia diminished it in a 
much greater degree than had been effected by the use, and 
that a very liberal one, of the alkalies in the same patient. 
This circumstance led Mr. Home to wish for a more com- 
plete investigation of the subject, and he requested me to 
assist him in the prosecution of it. Since that time many op- 
portunities have occurred of carrying on the inquiry during 
an attendance on patients, labouring under calculous com- 
plaints. 
It is proposed to lay the results of our joint labours before 
this Society, with a view to establish a fact of so much impor- 
tance in the treatment of those diseases. 
The four following cases, include the principal varieties of 
the disorder, which have been met with, and are therefore 
selected from among many others, to prevent unnecessary 
repetitions. In each of them the urine was occasionally care- 
fully analysed. 
CASE I. 
A gentleman, sixty years of age, who had been in the habit 
of indulging in the free use of acid liquors, had repeatedly 
passed small calculi composed entirely of uric acid ; his urine 
immediately after being voided, deposited at all times a con- 
siderable quantity of that substance, in the form of a red 
powder, and occasionally in larger crystals. 
Nine drachms of subcarbonate of soda, dissolved in water 
highly impregnated with carbonic acid, and taken in the 
course of the day at three doses, appeared to have no effect 
whatever on the formation of uric acid ; the red sand was 
MDCCCX. T 
