40© Mr. Tennant on the Composition of Emery. 
as that used by Mr. Klaproth, I obtained about ib,o grains of 
argillaceous earth, ,6 of siliceous earth, ,8 or ,g of iron, and ,6 of 
a grain remained undissolved. These numbers, reduced to parts 
of a hundred, are therefore, 
Argillaceous earth 8o 
Silex “ - - 3 
Iron 4 
Undissolved - - - “3 
go. 
Mr. Klaproth obtained from the Chinese corundum, after 
separating from it the particles which were attracted by the 
magnet. 
Argillaceous earth - - 84 
Silex - 6,5 
Iron - 7,5 
9 8 - 
As this analysis was no doubt conducted with greater care 
than mine, the loss of weight was less ; but the proportion of 
the ingredients is sufficiently near to show that the substances 
are essentially the same. 
From 25 grains of emery which appeared the most impreg- 
nated with iron, and yet retained its usual hardness, I obtained, 
argillaceous earth 12,5, silex 2, iron 8, and one grain was not 
dissolved ; or, per cent. 
Argillaceous earth 
50 
Silex 
8 
Iron 
32 
Undissolved » 
4 
94 - 
