m certain stony and metalline Substances, See. 193 
in 24 grains of oxide. Thus, if 145 grains of oxide contain 100 
of iron, about 16 \ are contained in 24 of oxide. This would 
suppose the 23 grains of alloy to consist of 16^- iron and 6% 
nickel; which, if the usual loss be added to the 1 6\ grains of 
iron, and deducted from the nickel, may not be very remote 
from the truth. 
I shall next examine the globular bodies, also irregularly dis- 
persed throughout the stone. A number of them were reduced 
to fine powder ; but nothing metallic could be separated by the 
magnet. As a preliminary experiment, I sought for pyrites,- by 
digestion with muriatic acid ; but no hepatic smell was in the 
least perceivable, nor was white carbonate of lead at all altered 
by being held over the mixture. I therefore conclude these 
globular bodies do not envelope either iron or pyrites. By 
way of analysis, I treated 100 grains with potash, in a silver 
crucible; and, after the usual application of a red heat, sepa- 
rated as much silica as possible, by muriatic acid and evaporation. 
The silica being collected on a filtre, carbonate of potash was 
added to the filtrated liquor; by which, a precipitate, almost 
wholly ferruginous, was produced. This precipitate was col- 
lected in the common way ; then boiled with potash, to extract 
alumina ; and, by supersaturating the alkaline liquor with 
muriatic acid, and precipitating by carbonate of ammonia, an 
earth was gathered, which I afterwards found to be partly, if 
not entirely, siliceous. After redissolving, in muriatic acid, the 
portion of the ferruginous matter rejected by the potash, I pre- 
cipitated by ammonia, what I took to be entirely oxide of iron ; 
but, after igniting it, and again attempting to redissolve the 
whole in muriatic acid, more silica was left. The non-existence 
of lime was proved, by the addition of carbonate of ammonia, 
MDCCCII, C C 
