1890.] on the Glow of Phosphorus. 75 



rarefying the atmosphere in which it is placed its volatilisation is 

 increased, which serves to account for the increased glow when the 

 pressure of the gas is diminished. When phosphorus is placed in an 

 atmosphere of hydrogen, nitrogen, or carbonic acid, these gases, when 

 brought into contact with oxygen, become luminous from the oxida- 

 tion of the vapour of phosphorus diffused through them. The rapidity 

 of volatilisation varies with the particular gas ; it is greatest in the 

 case of hydrogen, and least m that of carbonic acid. Indeed, a stream 

 of hydrogen gas at ordinary, temperatures carries away comparatively 

 large quantities of phosjjhorus, which may be collected by ajjpro- 

 priate solvents. No ozone and no glow are produced in oxygen gas at 

 ordinary temperatures and pressures, but on warming the oxygen both 

 the ozone and the glow are formed. On passing ozone into oxygen 

 at temperatures at which phosphorus refuses to glow, the phosphorus 

 at once becomes luminous, oxygen is absorbed and the characteristic 

 cloud of oxide is produced, and the effect continues fo long as the 

 supply of ozone is maintained. A drop of ether at once extinguishes 

 the glow. 



The ether is in all probability converted into vinyl alcohol with 

 simultaneous formation of hydrogen peroxide by the reaction indicated 

 by Poleck and Thummel 



CH3CH2\ n _i_ n - CH^CHOH , OH } 

 CH3CH2/ ^ + ^3 - CH2CHOH + OH S 



Formic, acetic, and oxalic acids are also formed by the action of 

 ozonised oxygen on ether. 



Phosphorus combines with oxygen in several proportions, and 

 the study of the mode of formation and properties of these oxides 

 is calculated to throw light uj)on the nature of the chemical 

 process which attends the glow of phosphorus. Certain of these 

 oxides have recently been the subject of study in the chemical 

 laboratories of the Normal School of Science. When phosphorus is 

 slowly burned in air, there is produced a considerable quantity of a 

 volatile substance, having a characteristic garlic-like smell which soli- 

 difies, when cooled, in bea-utiful arborescent masses of white crystals. 

 It melts at about 23°, and boils at 173°. In a sealed tube kept in the 

 dark it may be preserved unchanged, but on exposure to light, and 

 especially to bright sunshine, it rapidly becomes deep red. It slowly 

 absorbs oxygen at the ordinary temperature and pressure, but from 

 the mode in which the solid product of the reaction (P2O5) is deposited, 

 it is evident that the union only takes place between the vapour of the 

 oxide and the oxygen gas. Under diminished pressure the act of 

 combination is attended with a glow which increases in brilliancy it 

 ozone be present. On compressing the oxygen the glow ceases. No 

 ozone is formed during the act of oxidation. The degree of rarefaction 

 needed to initiate the glow depends upon the temperature of the 

 oxide ; the warmer the oxide the less is the diminution of pressure 

 required. By gradually warming the oxide the luminosity steadily 



