prepared from the lithic or uric acid. 425 
it. The colours of the solutions of this salt, and of potash, 
differ slightly from one another, and also from that of the 
purpurate of ammonia ; but it is not easy to describe these 
differences so as to render them intelligible, 
Purpurate of lime. This salt, when obtained by adding a boil- 
ing. saturated solution of the purpurate of ammonia to a solu- 
tion of the muriate of lime, exists in the form of a powder 
much resembling in colour the crust of the lobster before it 
is boiled. This salt is but little soluble in cold water; but in 
boiling water it is more soluble, and the solution is of a 
beautiful reddish purple colour. 
Purpurate of strontian. This salt obtained as above, with the 
nitrate of strontian, exists in the state of a dark brownish red 
powder, with a slight tinge of green. It seems to be more solu- 
ble than the purpurate of lime, and forms a purple solution. 
Purpurate of barytes. Obtained as before described, with 
the acetate of barytes, this salt assumes the form of a dark 
green powder, not apparently differing much in point of 
solubility from the purpurate of strontian ; and forming, like 
that salt, a purple solution. 
Purpurate of magnesia. This is a very soluble salt. Its 
solution is of a beautiful purple. 
Purpurate of alumina. When a solution of the purpurate of 
ammonia was added to a solution of alum, no perceptible 
change took place immediately ; but after some time the 
colour of the solution disappeared, and a small quantity of a 
white substance separated, which was presumed to be the 
purpurate of alumina, but it was not examined. 
Purpurate of gold. When a solution of the muriate of gold 
is dropped into a solution of the purpurate of ammonia, the 
