44 2 
Dr. Pearson's Observations 
ments with this mixture, Exper. 17, and 18, that any ad- 
vantage is to be expected from this addition ; at least not for- 
cutting instruments. 
I cannot confirm the opinion above delivered, that the com- 
mon metal of the ancients for cutting instruments was the al- 
lay of copper with tin, by the experiments of other persons, 
excepting those of Mr. Dize', in the Journal de Physique for 
1790, p. 272. He had only twenty-five grains of an ancient 
dagger to operate upon. This small quantity, however, af- 
forded tin and copper, as appeared on dissolution in nitric acid. 
But Mr. Dize' made several analytical experiments on eight 
different sorts of coins, Greek, Roman, and Gallic. It appears 
from these experiments that these coins contained from -p- of 
a grain to 24^- grains of tin in 100 grains of each of the old 
metals. And it appears that these coins contained no other 
metals but copper and tin. 
From the preceding experiments and observations we learn 
that tin was infinitely more valuable to the ancients than it is 
to the moderns : without this metal, it is not easy to conceive 
how they could have carried on the practice, and invented the 
greater part of the useful arts. Tin was even of more im- 
portance to the ancients, than steel and iron are to the mo- 
derns ; because allays of copper by tin would afford better 
substitutes for steel and iron, than any substitutes which the 
ancients, in all probability, could procure for allays of copper 
by tin. 
We see also the importance of Britain in times more remote, 
probably, than those of which we have any record, or tradi- 
tion ; being, in all probability, the only country which furnished 
the metal so necessary to the progress of civilization. If Mr. 
