CARBON VAPOR. 173 



WEIGHT AND HEAT UNITS OF CARBON VAPOR. 



Two volumes of carbonic oxide are produced from I volume 

 of oxygen, and hence from I volume of carbon. I cubic 

 metre of carbonic oxide weighs 1251 grams. I cubic metre 

 of oxygen weighs 1430 grams. I cubic metre of carbonic 

 oxide contains, then, one-half a cubic metre of oxygen weigh- 

 ing 71$ grams, and one-half a cubic metre of carbon vapor 

 weighing 536 grams. Hence I cubic metre of carbon vapor 

 weighs 2 X 536 = 1072 grams, and I kilogram measures 

 I : 1072 =0.9328 cubic metre. 

 Or 



i cubic foot of carbonic oxide weighs 546.78 grains. 

 I " " " oxygen weighs 624.85 " 



One cubic foot CO then contains % cubic foot of O and -J- 

 cubic foot of C. 



546.78- 312.425 = 234.355, 

 and 



2 X 234.355 = 468.71 grains, 



weight of i cubic foot of carbon vapor. 



One pound of carbon vapor measures 14.93 cubic feet. 



If we wish the heat-units of carbon in vapor without the 

 heat of vaporization, multiply the weight of a cubic metre by 

 the heat of combustion of solid carbon. If from wood charcoal, 



8137 X 1.072 = 8722(15699.6 B. T. U.). 

 If from diamond, 



7859 X 1.072 = 8424(14963.2 B. T. U.). 



If carbon vapor with its heat of vaporization be wanted, 

 take the heat of combustion of carbonic oxide which contains 

 carbon as vapor and compare it with the heat of combustion of 

 carbon, uniting with the same quantity of oxygen to form 



