188 



CHEMISTRY. 



tion in the chemical and vital operations going on in the 

 world. 



255. Phosphoretted Hydrogen, H 3 P. This is a colorless 

 gas having the odor of garlic. A beautiful phenomenon 

 attends its production if it be allowed to escape into the air. 

 Let about 30 grammes of potassium hydrate be put into a 

 small retort, Fig. 82, and pour in upon it half a tumbler of 



Fig. 82. 



water ; then add a bit of phosphorus-stick half an inch long 

 and a teaspoonful of ether, and apply the heat, the beak of 

 the retort being under the surface of the water in the bowl. 

 The ether has nothing to do with making the gas, but this 

 is made by the action of the phosphorus and potassium hy- 

 drate and water together. The object of the ether is to 

 prevent an explosion, which would be liable to occur if the 

 gas escaped directly into the air in the retort. The ether 

 does this very effectually, for, being vaporized by the heat, 

 it rises, driving the air out before it, and then the gas, which 

 is generated as the heat increases, passes out behind the 

 ether, which acts thus as a sort of advance-guard. The gas, 

 as it comes up out of the water in the bowl, takes fire spon- 



