C 4i 3 



as 732 to 10OOO. It burns by the action of an in- 

 flamed taper, when in contact with the atmosphere. 

 The proportion in which it combines is represented by 

 unity, or i. It is procured by the action of diluted oil 

 of vitriol, or hydro sulphuric acid on filings of zinc or 

 iron. It is the substance employed for filling air bal- 

 loons. 



4. Azote is a gaseous substance not capable of 

 being condensed by any known degree of cold : its 

 specific gravity is to that of common air as 95 1 6 to 

 10000. It does not enter into combustion under 

 common circumstances, but may be made to unite 

 with oxygene by the agency of electrical fire. It forms 

 nearly four fifths of the air of the atmosphere ; and 

 may be procured by burning phosphorus in a confin- 

 ed portion of air. The number representing the pro- 

 portion in which it combines is 26. 



5. Carbon is considered as the pure matter of 

 charcoal, and it may be produced by passing spirits of 

 wine through a tube heated red. It has not yet been 

 fused ; but rises in vapour at an intense heat. Its 

 specific gravity cannot be easily ascertained ; but that 

 of the diamond, which cannot chemically be distin- 

 guished from pure carbon, is to that of water as 350O 

 to 1000. Charcoal has the remarkable property of 

 absorbing several times its volume of different elastic 

 fluids which are capable of being expelled from it by 

 heat. The number representing it is 11 .4. 



6. Sulphur is the pure substance so well known 

 by that name : its specific gravity is to that of water 

 as 1990 to 1000. It fuses at about 220 Fahrenheit ; 



