by the reciprocal Action of Sulphur and Charcoal. 413 
the other extremity was fitted a very small lengthening tube 
communicating with a very small tubulated matrass, furnished 
with a tube for collecting the gases, the extremity of which was 
inserted into water. The whole apparatus had previously beer 
most carefully dried; and the whole being perfectly luted, the 
retort was heated a little to drive off all the air contained in the 
retort and in the tube. The luted tube was then gradually heated: 
scarcely had it become red, whenthere was aconsiderable explosion. 
The matrass and lengthening tube were driven a great distance, 
and broken to atoms. The tube appearing to be untouched, there 
was substituted, after every thing was cooled, another lengthening 
tube, and another small matrass fitted with a tube to collect the 
gases. The whole being well luted, the retort was heated 
longer than at first, on the idea that the explosion was owing 
to a small quantity of air which remained in the apparatus: the 
luted tube was made red hot, and the retort slightly heated. 
No gas was emitted. All the liquor having disappeared, the heat 
was gradually slackened, and I sealed hermetically with fat 
luting the extremity of the bent tube, after having dried it well 
with bibulous matter to prevent the admission of water. 
Next day the apparatus was taken to pieces: the tube was 
in part fused, but there was no fissure in it. When broken, 
the:e was found among the broken glass the copper, which was 
very brittle, and covered with a black, brilliant, light matter 
having the appearance of charcoal. It weighed 22°15 gr.: it 
had therefore augmented in weight 2-02 grammes: there was 
besides a little matter disseminated and incrusted in the melted 
glass. There were found in the matrass two or three grammes 
of a pink liquor of an acid taste, and so volatile that a few drops 
only could be collected. There remained in the retort a small 
black, solid residue, adhering strongly to the side of the retort, 
and in so small a quantity that it was impossible to examine it. 
Since no gas was extricated during this operation, if the hquor 
subjected to the experiment contained hydrogen, it must have 
been found in the new red-coloured liquor, which would account 
extremely well for its volatility, since the copper seems to have 
taken from it sulphur, and to have isolated from it a portion of 
charcoal. To ascertain this, I made the following experiment: 
The copper, which had become brittle, and covered with a 
blackish charry matter, was bruised in an agate mortar: the 
pieces of copper which were still ductile were separated from it, 
and about one part of pure crystallized mitre was added to it: 
the whole being pulverized and mixed, it was projected from the 
burning charcoal, and far from the furnace, into a red-hot 
Hessian crucible very clean. The deflagration was very prompt. 
Afterwards we treated with distilled water, filtered speedily, and 
precipitated 
