392 
Tin. 
and they are then beat on a stone mass with heavy ham- 
mers, one side of which is plain and the other rounded. 
The plates joined together are first beaten with the latter : 
when they become extended the number of the plates is 
doubled, so that they amount sometimes to eighty or 
more. They are then smoothed with the flat side of the 
hammer, and are beat till they acquire the length of six 
or seven feet, and the breadth of four or five. The small 
block of tin from which they are formed is at first ten 
inches long, six in breadth, and a line and a quarter in 
thickness. 
When the leaves are of less extent, and thin, from eigh- 
ty to a hundred of them are smoothed together. 
Tin extracted from the amalgam which has been em- 
ployed for silvering glass, exhibits a remarkable peculia- 
rity. When fused in an iron pan, its whole surface be- 
comes covered with a multitude of tetraedral prismatic 
crystals two or three lines in length and a quarter of a 
line in thickness. The interior of these pieces of tin, 
when cut with a chisel, have a grayer tint than pure tin, 
which is as white as silver. The latter crystallizes also 
by cooling ; but it requires care. When it begins to be 
fixed, decant the part which is still in fusion, and there 
will remain at the bottom of the crucible beautiful crystals 
of a dull white colour, which appeared to me to be cubes 
or parallelopipedons. 
The peculiar and constant crystallization of tin taken 
from the amalgam of mirrors, the leaden gray colour 
which the mass of this metal had, and the mystery made 
of the preparation of this tin, induced me to try whether 
I could not discover by analysis the substance mixed 
with it. 
Having calcined this tin in a test, it was reduced to a 
powder of a delicate red colour, and increased in its weight 
l- 25 thu The magnet attracted particles of iron, the re- 
