Tin. 
365 
pieces like icicles, by a smart blow of an hammer* : tin 
in this form is called by our own manufacturers grain tin, 
by foreigners virgin tin , or tears of tin : and they tell us, 
that its exportation from Britain is prohibited under pain 
of deathf . The tin which I used in the following expe- 
riments, was of this sort, but I first melted it, and let it 
cool gradually ; a circumstance, I suspect, of some con- 
sequence in determining the specific gravity not only of 
tin, but of other metals. I have put down in the follow- 
ing table, the specific gravity of this tin, and of the lead I 
mixed with it by fusion, and of the several mixtures when 
quite cold ; the water in which they were weighed was 
60 °. 
Weight of a cubic foot of lead, tin, See. 
Lead - 1 1270 oz. avoir. 
Tin - - 7170 
Tin 32 parts, lead 1—7321 
Tin 16 — lead 1—7438 
Tin 10 — lead 1—7492 
Tin 8 — lead 1—7560 
Tin 5 — lead 1—7645 
Tin 3 — lead 1—7940 
Tin 2 — lead 1—8160 
Tin 1 — lead 1—8817 
Blocks of tin are often melted by the pewterers into 
small rods ; I think the rods are not so pure, as the 
* This property is not peculiar to tin, I have seen masses of lead 
which, under similar circumstances, exhibited similar appearances, 
and it has been observed, that zinc, when heated till it is just ready 
to be fused, is brittle. 
t Ency. Fran3 and Mr. Bail me calls it etain en roche, a cause 
que sa forme resemble a des stalactites ; he says also, that its ex- 
portation is prohibited, but that he does not see the reason for the 
prohibition, as it is not more pure than Cornish tin : and in this ob- 
servation he is right, it is nothing but Cornish tin ia a particular 
form. Chym. par M. Baume, vol. III. p. 422, 
