1874.] iU.' [Houston. 



ether. It solidified at about 38° F. With larji^er specimens and under 

 more favorable conditions, the reduction may possibly be carried still 

 further. 



2d. Another peculiarity of the liquid modification is that of its non- 

 oxidation when exposed to direct contact of air. 



3d. As a result of this last mentioned property, the Tquid does not 

 shine in the dark. Ordinary and liquid phosphorus were exposed under 

 the same circumstances to the air in a dark room. The common variety 

 emitted the well known light, the other was entirely non-luminous. 



There result apparently two distinct varieties of solid phosphorus from 

 the solidification of the liquid modification. One is tough and waxy, like 

 the ordinary material, the other is quite brittle and crystalline. We have 

 noticed that in all cases well prepared specimens of the liquid produced 

 on solidification the second variety, while poor or indifferent ones the 

 first. We, therefore, regard that from which the second is produced as 

 the true liquid modification. 



The brittle crystalline solid thus produced conports itself somewhat 

 differently from the ordinary variety. It oxidizes rapidly in the air, and 

 raises its temperature so rapidly as to melt down into a liquid state, in 

 which it is very easily inflammable. 



In order to test whether the liquid modification underwent any change 

 of volume at the moment of solidification, the following experiment was 

 made : A small specimen was placed in a test tube, a,nd covered with 

 water. A stout glass tube, having one ead drawn out into a capillarj^, 

 was inserted into a cork, and tightly placed in the tube. The whole 

 apparatus was then filled with water to within an inch of the top of the 

 cipillary. No appreciable change of volume could be detected at the 

 moment of solidification, though it is possible that the dimioution of 

 bulk consequent on the passage from the liquid to the solid state, was 

 exactly neutralized by the expansion produced through the heat developed 

 by solidification. 



To test whether the temperature of the boiling point had any effect in 

 producing the liquid modification, stick phosphorus was boiled in a con- 

 centrated solution of zinc chloride. The result was a variety which with 

 difiiculty retained its liquidity, and on cooling, exhibited the waxy texture 

 of the ordinary material. A high boiling point cannot, therefore, be the 

 cause of the change. 



Experiments were also made to ascertain whether the new modifica- 

 tion were some compound of phosphorus with hydrogen. The result 

 seemed to show this not to be the case. It may be mentioned incident- 

 ally, that during the conduct of some of these experiments a fact not 

 generally known wa^ observed. In a bulb blown in the middle of a glass 

 tube small pieces of stick phosphorus were placed, and the ends of the 

 tube were drawn out. One of these was placed in connection with a small 

 hydrogen gasoaeter, and the phosphorus in the bulb melted by cautiously 

 applied heat. Combination of course ensued, and there escaped from the 

 free end of the tube a spontaneously inflammable hydride, whose tempera- 



