on the Combujtion of the Diamond. 179 
confumed. We at firft fufpected that there ftill remained a 
brilliant particle; but we foon judged that it was a vitrified 
point of the fupport, which was confirmed on in{peéting the 
pipe when drawn from the globe. The queftion now was 
to collec the products of the combuftion. No means feemed 
likely to be attended with more certainty than to introduce 
water of barytes into the apparatus, taking care to adhere, as 
nearly as poflible, to the proportions indicated for the fatu- 
ration of the carbonic acid, which we fuppofed mnft have 
been formed to prevent the uncertainty which the excefs of 
this re-agent might occafion in the refults. The whole ap- 
paratus being removed into the fhade, we began on the gth 
to draw out the pipe which ferved as a fupport, and obferved 
on it two flight fiffures occafioned by the contraction, and a 
{pot of four or five millimetres in diameter, the centre of 
which had a vitreous appearance, and its edges a reddifh hue. 
On examining it with a magnifying glafs, we obferved at the 
loweft point a fpace of two or three millimetres diameter, the 
furface of which was really vitrified, but of a tarnifhed and 
unequal colour. We diftinguifhed a particle of white glafs, 
pure and brilliant, formed into a globule fome fmaller por- 
tions of the fame nature, and two fmall globules of a vitreous 
fubftance, which had a greenifh red colour, 
On one fide we obferved on the edges feveral other very 
fmall globules interfperfed in a yellowifh ground, and on the 
oppofite a flight tinge of very bright red with very {mall red- 
difh points. A particle of white earthy matter was at firft 
taken for a fragment detached from the edges of the pipe, 
but it was found friable, and afcertained, by the ftain it left 
on gold, to be oxyd of mercury. This examination being 
finifhed, we introduced into the globe five meafures of fatu- 
rated water of barytes, each of 46°5 cubic centimetres. The 
liquor immediately aflumed a milky appearance, and there 
was a diminution in the volume of gas, which, calculated by 
means of the attached paper {cale, amounted nearly to 300 
cubic centimetres. Thus we might ftop here and confider 
the experiment as terminated, and by making fome allow- 
ance for the errors unavoidable in fuch manipulations, and , 
make the refult tally with the amount, determined before by 
the noble experiment of Lavoifier and La Place, of the re- 
Aaa {pective 
