Chemistry and Physics. . 493 



carbon disulphide, and the solution contained ordinary phos- 

 phorus. Moreover, the yellow undissolved portion burned in the 

 air like ordinary phosphorus. Similar experiments were made 

 with other solvents or in vacuo, with similar results. When 

 diffused daylight only was employed, the first precipitate was 

 sulphur-yellow, passing to orange and after some months to a 

 bright red. It was readily dissolved by dilute sodium hydrate 

 solution, on boiling. As the particles of allotropic phosphorus 

 grow larger, they appear to deepen in color. Formed at high 

 temperatures, the precipitate is darker in color. Comparing this 

 product with commercial red phosphorus, and with the so-called 

 metallic or rhombohedral phosphorus, the author concludes that 

 the term " amorphous" is misleading since the great bulk of the 

 powder thus designated consists of transparent ruby-red, more or 

 less crystalline particles which polarize light. By elutriation, it 

 can be separated into a very fine red powder, and into almost 

 black shining particles which under the microscope are crystalline 

 and transparent, transmitting a ruby-red light. Both are acted 

 on by sodium hydrate solution, the action being greater as the 

 particles are finer. Moreover, on heating the red phosphorus to 

 305°-310° for two hours or even to 326° or 357° no sign of any 

 change could be detected in it. But at 445°, the temperature of 

 boiling sulphur, a certain amount of vapor was produced which 

 was oxidized on contact with the air. In vacuo, about one-fifth 

 of the red phosphorus sublimed as ordinary phosphorus into the 

 upper and cooler portions of the tube, when heated at 445°. The 

 author believes therefore that no change takes place in red phos- 

 phorus below 358°, and that even up to 445° it is exceedingly 

 slow. Experiments upon the permanency of this variety of 

 phosphorus in the open air showed that so far from being the 

 inert and stable substance it is usually supposed to be, it is prone 

 to change, being easily oxidized even in the air, and readily 

 deoxidizing phosphoric acid. The so-called metallic phosphorus, 

 prepared either by dissolving ordinary phosphorus in lead at high 

 temperatures, or better by projecting red phosphorus on the 

 surface of melted lead, and then removing the lead with nitric 

 acid, was obtained as a crystalline powder consisting of rhombo- 

 hedrons, some darker and some lighter in color than the ordinary 

 red phosphorus. This variety of phosphorus polarizes light in 

 the same manner, is acted upon similarly with sodium hydrate 

 and behaves in a similar manner when heated. Hence the author 

 concludes that the metallic and the red are the same allotropic 

 form of phosphorus, and recommends that the term " amorphous " 

 be discarded. — J. Chem. Soc, lvii, 599, July, 1890. g. f. b. 



3. On the Action of Fluorine on Carbon. — Moissak has ob- 

 served that fluorine and carbon combine with great energy even 

 at ordinary temperatures. Lampblack, purified and dry, becomes 

 incandescent at once in fluorine and wood-charcoal takes fire in it 

 spontaneously. Denser forms become incandescent in fluorine 

 only on heating to 50° or 100°. Graphite from cast iron unites 

 with fluorine below redness and Ceylon graphite and gas carbon 



