GASEOUS BODIES. 77 



ing one of the ingredients of all oils, fat, bitumen, tec., 

 while carbon forms the other. Hydrogen gas unites 

 with several other substances, forming compounds, as 

 carburetted hydrogen,* sulphuretted hydrogen, f phos- 

 phuretted hydrogen 4 and others, being severally carbon , 

 sulphur, and phosphorus, in union with hydrogen gas. 



There are one or two other gases, which it is intended 

 to notice, on account of their peculiar nature and strik- 

 ing qualities. 



The first of these is Chlorine, which takes its name 

 from its colour a greenish yellow. It possesses the pe- 

 culiar property of supporting combustion, while it will 

 not support life. If attempted to be respired, it produces 

 a sense of strangulation, with a violent coughing and 

 spitting of blood, yet in contagious diseases, as the 

 typhus fever, cholera, &c., fumigations of this gas will 

 destroy the contagion, and very generally preserve 

 health. "Water readily combines with chlorine, and ac- 

 quires the property of discharging the colours of printed 

 linens and muslins. If any of the metals in powder or 

 leaves, as antimony, Dutch metal, gold-leaf, &c., be 

 thrown into a vessel filled with this gas, they will in- 

 stantly ignite. 



Chlorine is made for experiment as follows : Mis 



Common coal gas is carbnretted hydrogen gas, and its brilliancy 

 is produced by the carbon. It may be made in a pure way by mixing 

 one part of alcohol or spirits of wine with_/or parts of sulphuric acid, 

 and subjecting the mixture to the heat of a lamp in a glass retort. 

 This is also called the Olefiant gas. 



t It is sulphuretted hydrogen gas which escapes from drains, and 

 is of a very poisonous nature, even when much diluted with atmos- 

 pheric air. A dog would die speedily in an atmosphere containing 

 one part in 800 of this gas, and a horse in an atmosphere containing 

 one part in 250. 



J Phosphuretted hydrogen gas is the most combustible body 

 known ; it ignites spontaneously in atmospheric air. It may be made 

 by putting some small bits of phosphorus into a small glass retort, and 

 pouring over it some liquor potassa. The heat of a lamp should be 

 applied, and the beak of the retort ^be immersed in a vessel of very 

 warm water. It will soon generate, and each bubble will ignite with 

 a sudden flash at the instant of its extrication. 



^ Chloride of lime is now generally used for this purpose ; a table- 

 spoonful is dissolved in a glass of water, and sprinkled about the 

 room. 



