on certain stony and metalline Substances , &c. 
211 
EXAMINATION OF IRON FROM SENEGAL, BROUGHT BY GENERAL 
O'HARA, AND GIVEN TO ME BY MR. HATCHETT. 
In this experiment, 199 grains of oxide were produced from 
1 45 grains of metal : hence, there may be an estimation of 8 
grains in 145, or between 5 and 6 per cent, of nickel. 
It will appear, from a collected view of the preceding pages 
and authorities, that a number of stones asserted to have fallen 
under similar circumstances, have precisely the same characters. 
Ihe stones from Benares, the stone from Yorkshire, that from 
Sienna, and a fragment of one from Bohemia, have a relation to 
each other not to be questioned. 
ist. They have all pyrites of a peculiar character. 
adly. They have all a coating of black oxide of iron. 
3dly. They all contain an alloy of iron and nickel. And, 
4,thly. The earths which serve to them as a sort of con- 
necting medium, correspond in their nature, and nearly in their 
proportions. 
Moreover, in the stones from Benares, pyrites and globular 
bodies are exceedingly distinct. In the others they are more or 
less definite ; and that from Sienna had one of its globules trans- 
parent. Meteors, or lightning, attended the descent of the stones 
at Benares, and at Sienna. Such coincidence of circumstances, 
and the unquestionable authorities I have adduced, must, I 
imagine, remove all doubt as to the descent of these stony 
substances ; for, to disbelieve on the mere ground of incompre- 
hensibility, would be to dispute most of the works of nature. 
Respecting the kinds of iron called native, they all contain 
nickel. 1 he mass in South America is hollow, has concavities, 
