NEW SOLVENT FOR STONE IN THE BLADDER. 229 
fifth number of the Pharmaceutical Journal, vol. i., that one 
grain of crystals of soda, dissolved in an ounce of water, 
took up only one grain of uric acid — that one grain of car- 
bonate of potash took up 1.4 grains — one grain of borax, 1.2 
grains— and four grains of bicarbonate of soda, 1.1 grains. 
Hence it follows that the solvent power of carbonate of lithia 
is more than double that of carbonate of soda; nearly double 
that of carbonate of potash or borax; and about eight times 
that of bicarbonate of soda, which is the active ingredient of 
the Vichy water. 
A human urinary calculus, now on the table, of the Socie- 
ty, composed of uric acid, with alternate layers of oxalate of 
lime, having been most accurately poised, after being previ- 
ously brought to hygrometric repose, by digesting in fresh 
urine, and then carefully dried, was placed in a solution of 
four grains of carbonate of lithia, in an ounce of distilled 
water, and steadily maintained at a blood-heat by means of 
a water bath, during five consecutive hours. On being with- 
drawn, nicely washed, and again dried as before, it was found 
to have lost five grains in weight, which is at the rate of one 
grain an hour. The calculus is deeply eroded in different 
parts, but the delicate laminae of oxalate of lime remain in- 
tact, imparting to the surface the appearance of deep etch- 
ing. The menstruum acquired a pale yellow tinge> and 
there fell down from it, on cooling, a light flocculent depo- 
sit of urate of lithia, in which silky crystalline tufts could be 
discerned by help of the microscope. It was still alkaline 
to litmus. Decomposed by means of hydrochloric acid, it 
yielded nearly three grains of pure uric acid. 
In another experiment, the remaining half of the same 
calculus being allowed to stand during four hours in two 
ounces of the natural Vichy water, from the spring called 
Hopital, (containing three grains and a half of carbonate of 
soda,) was found to have parted with two-tenths of a grain 
of uric acid; while the former portion of the calculus, placed 
under precisely similar circumstances, at the same time, in 
