Seven solutions
Beginning then with the pure double nitrate of silver and thallium, this will isolate the stones of less specific gravity than 4.7963, and taking the lighter solutions and standardising them, we may get seven solutions which will isolate the stones as follows:
A shows the stones which have a specific gravity over 4.7963
B ” ” ” 3.70 and under 4.7963
C ” ” ” 3.50 ” 3.70
D ” ” ” 3.00 ” 3.50
E ” ” ” 2.50 ” 3.00
F ” ” ” 2.00 ” 2.50
G ” ” – – under 2.00
Therefore each liquid will isolate the stones in its own group by compelling them to float on its surface; commencing with the heaviest and giving to the groups the same letters as the liquids.
