352 Quantity of Matter having [May, 
Nitrate of lead .......... Dense white gelatinous precipitate, 
redissolved by nitric acid. 
Nitrate of silver.......... Ditto, but not gelatinous. 
Nitrate of mercury ...... Dense white flocks, 
Proto-sulphate of iron .... Becomes yellow. 
Persulphate of iron ...... O 
Sulphate of copper ...... O. 
The precipitate formed when nitrate of lime is dropped into tar- 
trate of potash shows that the acid in the Chinese salt is not the 
tartaric. 
Effect of Re-agents on Citrate of Potash. 
Witrate sof ARG a1». 5) piajoiasinrey 
Muriate of barytes........ Copious white flocks, nearly, but not 
completely, redissolved by nitric 
acid. 
Nitrate of strontian ...... A copious white precipitate. 
Sulphate of magnesia .... O. 
Nitrate of lead .........+ Copious white flocks, redissolved by 
nitric acid. 
Nitrate of silver.......... A white precipitate. 
Nitrate of mercury ...... Ditto, 
Proto-sulphate of iron .... Becomes yellow. 
Persulphate of iron ...... O. 
Sulphate of copper ...... O. 
These experiments coincide with the effects of the same re-agents 
on the acid of the Chinese salt. I should, therefore, have concluded 
that the salt in question was a citrate of mercury; but I was not 
able to produce a similar salt, either by digesting oxide of mercury 
in citric acid, or by decomposing nitrate of mercury by citrate of 
potash. My citrate was always a powder, and never in scales. I 
ought to have mentioned that the Chinese salt contains a mixture of 
gypsum. Probably, therefore, their mode of preparation is com- 
plicated : and I had projected some experiments to verify a conjec- 
ture respecting the mode which they may have practised; but want 
of leisure has hitherto prevented me from putting them in execu- 
tion. Should they be attended with Success, I may at some future 
time lay the results before my readers.—T. 
ArTICLE LY. 
On the Quantity of Matter having an Influence on Chemical Action. 
By M. P. 
Ir has been advanced by Berthollet, and supported by some other 
chemists, that the quantity of matter has,an influence on chemical 
