422 
Dr. Pearson's Observations 
but quite malleable. It was about as hard as the allay of 
twenty parts of copper by one of tin, and consequently was 
not nearly so hard as the softest of the ancient metals. 
Experiment 20. loco grains of copper with 500 grains of 
a small round steel file wjere exposed to fire, as stated ‘in the 
last experiment. On opening the crucible, part of the steel 
only was found to have been melted and united to the copper; 
but the other part of the steel which retained its form, was 
thoroughly impregnated or penetrated by copper ; so that on 
breaking the part which had not been melted, and which was 
very brittle and porous, it was in appearance imperfectly me- 
tallized copper. The part of the allay which had been melted 
was not, as far as I could perceive, different from the allay of 
the last experiment, except that it was a little harder ; being 
thought to be about as hard as brass. 
I have not hitherto set down the specific gravities of the 
above allays, because I thought it most useful to make the 
statement of them together in one column, with, at the same 
time, the specific gravities of different parcels of copper, tin, 
zinc, brass, and bell-metal. 
* By shotted copper is meant copper which has been poured when melted into cold 
water, by which it is divided into small globular pieces and grains. 
Specific Gravities. 
1. Plate of copper, a little hammered 
Another specimen, a little hammered 
Copper ingot 
Another specimen of ditto 
Shotted copper* 
8,8 
8,904 
8,418 
8,414 
8,08 
7>3 
2. Tin 
