•202 
DR. BENCE JONES ON THE SOLUTION OF URIC ACID CALCULI 
Section I. On the Solution of Uric Acid Calculi. 
After a few preliminary experiments, on the 3rd of July the first experiment was 
made • a piece of very compact uric acid calculus was put into a saturated solution 
of nitrate of potassa, between the electrodes of a battery consisting of ten pairs of 
Grove’s plates. The fluid soon boiled ; the action was continued between three and 
four hours, when the calculus was removed. It was found to be so deeply corroded 
and worn on both sides, that apparently nearly half the piece of uric acid calcu us 
was gone (see Plate XIV. fig. (a) and {h). The solution of nitre was boiling the 
whole time. On the removal of the stone a few drops of the liquid were evaporated, 
and the evidence of uric acid was most distinct. The fluid was evaporated to dr^mess 
treated with a drop or two of nitric acid, again evaporated to dryness, and expose 
to the fumes of ammonia. The characteristic reaction of uric acid was obtained. 
Hence by this qualitative experiment, it was certain that at a boiling temperature 
uric acid’between the electrodes could be dissolved in a saturated solution ot nitre 
The question immediately arose, what effect would be produced when the solu- 
tion of nitre was diluted, and when the temperature was about that of the human 
Experiment 2.— The number of plates in the battery was reduced to one-half in 
order that the temperature might rise less rapidly. Only five pairs of plates were 
used. Ten cubic inches of saturated solution of nitre were mixed with thirty cubic 
inches of distilled water; the specific gravity of the mixture was 1029. The tempe- 
rature was kept low by changing the solution in which the calculus and the electrodes 
were placed. Each glass contained nearly a pint of the solution of nitre. The piece 
of calculus weighed 48 grains, and it consisted of very compact uric acid. 
The action began at 9^^ 45” a.m. and was continued to 1 p.m., the temperature o 
the solution being between 65° and 108°. 
The action recommenced at 2»' 10” p.m. and was continued 
to 5 P.M., the tempera- 
ture being between 65° and 112°. 
Total time 6'" 5”. • i t f 
The calculus was then removed and perfectly dried in a water-bath. It was not 
washed with water, so that some nitre probably remained on the calculus ; when pei- 
fectly dry the uric acid weighed 37 grains. Hence, in six hours at least, 11 grams 
of uric acid were dissolved. The solution appeared to take place chiefly at the 
negative pole. The nitre solution became very slightly alkaline. 
Experiment 3.— I was then anxious to know whether a larger piece of calculus and 
increased power of the battery would give me a satisfactory result ; the piece of cal- 
culus weighing 113 grains, consisted chiefly of uric acid, but the nucleus was oxalate 
of lime. The battery consisted of ten pairs of plates, and the electrodes and solution 
were the same as in the last experiment. 
