29 
found in the colon of a young man after death. 
soluble in alcohol, gave no precipitate with solution of corro- 
sive sublimate, but an abundant white one with infusion of 
galls. The solution by caustic soda (4), neutralized by weak 
acetic acid, gave also an abundant precipitate with infusion of 
galls, and none with corrosive sublimate. It was darker 
coloured than that obtained by water alone. In the third 
process, alcohol dissolved a small portion of resin, which 
water precipitated again perfectly white. 
The muriatic acid dissolved the phosphates, and left the 
vegetable fibre. 
To ascertain the relative quantities of the two phosphates, 
I destroyed the animal and vegetable matter of a fresh por- 
tion of the calculus by burning, dissolved the phosphates in 
muriatic acid, and precipitated them together by ammonia; 
I then digested the precipitate, whilst moist, in oxalic acid, 
filtered, and threw down the triple phosphate by ammonia, 
adding also a little phosphate of soda to secure the precipita- 
tion of the whole of the magnesia. The oxalate of lime was 
then decomposed by heat, its base re-dissolved in muriatic 
acid, and precipitated by sub-carbonate of ammonia, and the 
quantity of phosphate of lime inferred from that of the car- 
bonate obtained. The proportions of the several ingredients 
of the calculus were as follows : 
2 1 
| Animal matter, chiefly gelatine 
3. Resin - 
| Ammoniaco-magnesian phosphate 
j Phosphate of lime - 
6. Vegetable fibre - 
25 . 20 
3 
5 
45 
20 
90 
16 
34 
30 
99 • , 9 ° 
j 
