178 METALLOIDS. 



combustion of phosphorous, which takes place without 

 kindling. The product of the combustion, is a white 

 powder, called phosphorous acid, which soon becomes 

 liquid, by absorbing moisture from the air. 



435. A HARMLESS FIRE. By agitating 



How may a . 



harmless fire phosphorus with ether, a small portion of 

 be produced 9 the f ormer su bstance is dissolved. This 

 solution, if rubbed upon the face and hands, makes 

 them luminous, in the dark. This is another case of 

 phosphorescence. A piece of phosphorous of the 

 size of a pea is amply sufficient for the experiment. 



436. COMBUSTION UNDER WATER. Phos- 

 How may 



phosphorus be phorus may be burned under water, by the 



^te??*** hel P of substances ricn in oxygen. Chlo- 

 rate of potassa is such a substance. Place 

 a few scales of this salt, and a bit of phospho- 

 rous of the size of a pea, at the bottom of a 

 wine glass previously filled with water. Par- 

 tially fill the bowl of a pipe with oil of vitriol, 

 and drop it in small portions on the mixture, 

 bringing the pipe stem, each time, close to the bottom 

 of the glass. As soon as the stronger acid is applied, 

 chloric acid, containing much oxygen, is liberated and 

 decomposed, and the phosphorus inflamed. A similar 

 combustion of phosphorus, by means of nitric acid, 

 has already been described. 



437. FRICTION MATCHES. Ordinary 



What is said 



of friction phosphorus is too inflammable to be em- 

 ployed in the manufacture of friction match- 

 es. By heating it under carbonic acid for a long time, it 

 becomes changed in color, and also less fusible and in- 



