in the Structure of Calculi. 243 
therefore so frequently observed during the use of an alkali, 
arise, not from any actual solution of calculous matter, but 
from the power which it possesses of diminishing the secretion 
of uric acid, and thus preventing the enlargement of the cal- 
culus, so that, while of a very small form, it may be voided 
by the urethra. 
