Brass* 
3e?cf 0 
125 
mixed with aliments. What have We to fear from such 
vessels ? Small particles which may be detached by the 
fork or the knife ? Such fears are groundless. Let us 
apply, then, to vessels of tin, in regard to their use, what 
we have said of tinning, that the fears entertained in re- 
gard to the employment of it are not proved by any facts 
well authenticated ; and if the art of the pewterer is sus- 
ceptible of improvement, either in regard to health or prac- 
tice, it cannot be expected from mixtures which have al- 
ways been rejected by sound chemistry. Besides, we 
know several other mixtures which might be tried before 
we have recourse to a metal so soluble, and so difficult to 
be worked, as zinc. 
Let us now form a parallel of the alloys we have exa- 
mined, with those used by the pewterers. 
Pure tin forms the first quality, which they employ for 
the best utensils and those most esteemed. 
The second kind of mixture contains an eighth of lead, 
and serves for making common vessels. 
The third kind contains 0.15 of lead, and is employed 
for drinking- vessels. 
The first kind, which is the most common, contains 
0.20 of lead, and is employed for making ink-stands and 
other small articles. 
From what has been said it may be seen, that if pewter- 
ers employ sometimes for common vessels the fourth kind 
of mixture, the public can be exposed to no danger. The 
ancients, who made so much use of tin vessels, have left 
us no certain facts which prove that the use of them was 
contrary to health, and medicine never proscribed them. 
[21 Till 313— 319. 
To Separate Copper from Silver , by M. Go et ling. 
Four methods are known for separating copper from 
silver, in all of which the alloy is dissolved in the nitric 
acid. As the price of this acid is high, M. Goetling, in 
