PROOFS OF THE COMBUSTIBILITY OF DIAMOND.

1-3

The combustion of the diamond is effected at three differenttemperatures. At the first and least elevated temperature thediamond assumes a grey and black colour; this is the first degreeof oxidation; it is the state of the plumbago and of the antraco-lite, or incombustible pit-coal.

At the second degree of temperature there is a new, slow andsuccessive combination of oxigen; it then constitutes the habi-tual state of our charcoal.

Supposing therefore we could operate with sufficient precisionto take from the surface of the diamond, the black matter in pro-portion as it formed, during our experiment for burning it, weshould undoubtedly convert the whole diamond into charcoal.

At the third degree of combustion the diamond is wholly con-verted into carbonic acid gas, as we have shown before.

Guyton has likewise converted soft-iron into cast-steel, by-means of the diamond, in the following manner:* A cavity wasbored in a block of soft-iron, and a stopper fitted to it of the samemetal. Into the cavity was put a diamond, with some filings ofthe block of iron, to fill the remaining space, after which thestopper was driven in. In this state the whole was put into acrucible and this placed into another. The space between thetwo crucibles was filled with pure siliceous sand. The externalcrucible was well closed and luted, and the whole exposed tothe strong ignition of a blast-furnace, by which the metal wasfused completely'; the diamond disappeared and the iron wasthus converted into steel.

After all this, it will no doubt be demanded how it happens,that the pure carbon or diamond is so scarce, whilst when com-bined with oxigen in the state of charcoal it is so abundantlydispersed through nature ?

We obtain by our chemical decompositions of bodies charcoalsand not diamond. No chemist speaks of our exhaling diamondby respiration, but many of charcoal or at least carbonic acid.

Annales dc Chcm. XXXI, p. 328.