210 DR. BENCE JONES ON THE SOLUTION OF OXALATE OF LIME CALCULI 
When dry the stone weighed 60 grains, so that in three hours and a quarter 
4 grains were dissolved. 
The loss was chiefly on the cut surface, which was in contact with the negative or 
alkaline electrode. The surface was not regularly attacked, but some ridges were 
left, one very distinct, consisting of oxalate of lime. The external surface wa^ below, 
and the acid appeared to have little or no effect on it. 
It seemed from these experiments that uric acid and oxalate of lime together were 
more easily dissolved than oxalate of lime alone. 
To determine whether oxalate of lime with the earthy phosphates was more soluble 
than oxalate of lime alone, the following experiments were made. 
Experiment 14.— A whole calculus, consisting externally of oxalate of lime with 
phosphate of lime, weighing 186 grains, was acted on by twenty pairs of plates in the 
solution of nitre of the same strength as before. 
The action began at 9'^ 30“ a.m. and was continued to 1 p.m., the temperature of 
the solution being between 68^ and 120°. 
The action recommenced at 2^’ 5“ p.m. and was continued to 35“ p.m., the tempe- 
rature being between 70° and 100°. 
The total time was The last hour there was very little action of the batter}. 
The calculus when dry weighed 159 grains, so that in five hours 27 grains were 
dissolved ; the result in this experiment was so much beyond my expectation that 
the same calculus was again submitted to the same reagents. 
Experiment 15. — One grain having been removed for analysis the calculus weighed 
158 grains. 
The action began at 9^ 40“ a.m. and was continued to 12*' 45“ a.m., the tempera- 
ture being between 65° and 130°. 
The total time was 3*' 5“. 
When the calculus was dry it weighed 143| grains, so that in three hours and fi\e 
minutes the calculus lost 14^ grains. 
The result of these experiments with oxalate of lime and uric acid, and with oxalate 
of lime and phosphates, may be thus arranged ; — 
Average temp. 
109 
no 
94 
103 
113 
Pairs of 
plates. 
20 
20 
20 
20 
20 
Grs. dissolved. 
4 
5 
4 
27 
14i 
Exp. 11 lasted 3 25, in solution of nitre water | 
Exp. 12 lasted 3 23, in solution of nitre water f 
Exp. 13 lasted 3 16, in solution of nitre i, water f 
Exp. 14 lasted 5, in solution of nitre water f 
Exp. 15 lasted 3 5, in solution of nitie -j, water .j. 
Hence the oxalate and urate together can be slowly dissolved in the nitre solution, 
whilst the oxalate and phosphate together ai’e very rapidly dissolved, namely, at the 
i-ate of from 4^ to 5^ grains an hour. 
It appears then from these experiments that calculi consisting of oxalates witli 
phosphates are very easily dissolved in a dilute solution of nitre at the tempm-atui’e ot 
the body by the aid of electi-icity ; but that calculi consisting of oxalates with ui-ates 
