Brass i 
124 
prove that tinning, the half even of which is lead, cannot 
fee dangerous in domestic purposes ; and that, to be hurt- 
ful to die health by the contact of alimentary acids, it 
would be necessary that the pans should be pure lead, or 
tinned with that metal only, which is impossible. 
Paragraph IV, 
On Tin Vessels . 
It was necessary to examine the action of vegetable 
acids on vessels of tin. For this purpose the author caus- 
ed the following vessels to be made : 
1st, Pure tin, 
2d, Tin having - 0.05 of lead, 
3d, Ditto - ~ 0.10 
4th, Ditto •? - * 0.15 
5th, Ditto - * 0.20 
6th, Ditto - - 0,25 
7th, Ditto o * 0,30 
8th, Ditto = t 0o5Q 
9th. Of pure lead. 
AH these vessels were filled with boiling vinegar, which 
was left in them three days. The vinegar of the first 
eight vessels being subjected to the examination of re- 
agents, did not give the least signs of the existence of lead, 
but of some particles of tin. The vinegar in the ninth 
vessel was much saturated with lead. 
The same experiments, repeated at three other times, 
with vinegar of greater or less strength, exhibited the 
same phenomena, In these cases it was observed that 
the first eight vessels had assumed the colour of lead, and 
exhibited the same phenomena as those indicated in re- 
gard to tinning in the preceding paragraph. 
The author, after supporting his observations by those 
ofBayen and those of Vanquelin, deduces this conse- 
quence : Tin alloyed with lead is harder than when it is 
pure ? and less susceptible of suffering its particles to be 
