Volume 1
A treatise on chemistry / by H.E. Roscoe and C. Schorlemmer.
- Henry Enfield Roscoe
- Date:
- 1877-1892
Licence: Public Domain Mark
Credit: A treatise on chemistry / by H.E. Roscoe and C. Schorlemmer. Source: Wellcome Collection.
601/792 page 585
![a compound of metallic iron with carbon, and its composition corresponds approximately with the formula CFe4. In the molten condition, however, it can dissolve a much larger quantity of carbon, up to as much as 4 per cent, of its weight This excess crystallizes out as graphite when the metal cools. The coarsely crystalline grey pig-iron owes its peculiar pro- perties as well as its appearance to the presence of graphite, and when this form of iron is dissolved in acid, scales of graphite remain as an insoluble residue. Graphite also occurs in certain meteoric masses, as, for instance, in the meteorite which fell in 18bl at Cranbourne near Melbourne, and this meteoric graphite is, according to Berthelot, identical in properties with iron-graphite. We may thus conclude that the meteoric mass in which it has been found has been exposed to a very high temperature. It appears not improbable that iron-grapliite originates from the decomposition of the cyanides which occur in the blast furnace. According to Wagner, the black deposit which is formed by the spontaneous decomposition of hydrocyanic acid, CNH, contains graphite, as may be seen by washing the deposit with strong nitric acid, when the insoluble scales of graphite will be left behind.1 Another remarkable mode of production of graphite, also most likely from cyanogen compounds, was first observed by Pauli2 in the manufacture of caustic soda from the black-ash liquors. These liquors are evaporated to a certain degree of consistency, and Chili saltpetre is added to oxidize the sulphur and cyanogen compounds present. Torrents of ammonia are thus evolved, and a black scum of graphite is observed to rise to the surface. When the vapour of chloride of carbon is led over melted cast iron, ferric chloride is evolved, and carbon dissolves in the iron until it becomes saturated, after which hexagonal plates of graphite separate out.3 The carbon which occurs in crystalline boron remains as amorphous carbon when the diamond boron is heated to red- ness. When it is heated to whiteness it takes the form of graphite. Graphite in its chemical relations occupies a position totally distinct from that of all other forms of carbon; amongst them- 1 o Wagner’s Jcthrcsb. I860, p. 230. Phil. Mag. [4], xxi. 541.](https://iiif.wellcomecollection.org/image/b28122409_0001_0603.jp2/full/800%2C/0/default.jpg)
