- 
. 
- on the Combuftion of the Daetd: 54 
tegard to the correfpondence of the ingredients and the pro- 
ducts, I muft not omit to remark, that I had, as.co-opera- 
tors in thefe, experiments, C. bihaiies and Hachette. The 
journal of them was ¢orrectly kept by C. Deformes, formerly 
a pupil of the Polytechnic’School, and at prefent affiftant- 
preparer for one of the courfes of chemifiry. The moft im- 
portant phenomena were feen, at different fittings, by feveral 
men of letters. 
» The Couricit of the Adminiftration of the Polytechnie 
School, approving the objeé& of the experiments, authorifed 
me to difpofe of fomé of the diamonds in its cabinet *. 
The firlt experiment was made on the gth of Fructidor 
in the year,5. We placed upon the table of the mercurial, 
pneumatic tub, a bell of flint glafs 18-3 centimetres in di- 
ameter, and of the content of 5580 cubic centimetres. Near 
the tub was placed, on one fide, a pneumatic machine, to 
exhauft the common air from the bell by means of a bent 
tube, which rofe as far as the knob. .On the other fide was 
a water pneuthatic tub, bearing a large receivers having at 
* its tubulure a cock which bitainbinieated with the infide 
of the bell by a tube of bent elafs,, and rifing, in the like 
fhanner, to the hollow knob of the bell. On one of the 
edges of the mercurial tub was fixed a flide, bearing a kind. 
of mandril, deftined to receive a cylinder of hard wood move- 
able in eyery direétion; terminated by a handle of iron, and 
ferving to fupport a cup made of the crucible earth of Va- 
loone; {o that this cup could be cofveyed to every point of the 
interior part of the bell to prefent the diamond to the focus, 
This apparatus is reprefented by fig. 1. (Plate II.) Every 
thing being difpofed in this manner, we put into the eup 
’ 
: 
¥ 
4 
* The diamonds, whieh form -part of its collection of minerals, were 
found in an Englith fhip from Senegal, captured in the year 2. They 
were depofited at the Hotel det monnoies; where thy-remiined till the 
year 5, when, on the fuggeftion of our colleague Mongez, one of the ad- 
“niniftratays, the cvinider of the finances, after caufing it to be afcertained 
that the greater part of them were unfit for being cut, and for that reafon 
more valuable for inftruétion, ordered one third of thein to be given to 
“the Mufeum of Natural Hiftory, another to the Cabinet of the School of 
Mines, and another to that of the Polytechnic School. ‘The lot affigaed 
‘to the laft confitted of 26, weighing altogether 3-662 grammes, 
Vor. V. I an 
