46 On the Composition of [Jt'LT, 



of carbonic acid gas. The cubic decimetre (61*028 cubic inches) 

 of this gas weighs 0-75804 gramme (11*707 grains). 



One hundred parts by weight of this gas are composed of 



Carbon .... 57*574 1 10*189 hydrogen in excess above 

 Oxygen ... 28*466 > 32*237 parts of water reduced to its 

 Hydrogen. . 13*960 j elements 



100*000 



One hundred parts in volume of the gas from the decomposition 

 of ether consume 152*48 measures of oxygen, and form 101*89 

 measures of carbonic acid. The cubic decimetre (61-028 cubic 

 inches) of this gas weighs 0*85808 gramme (13*252 grains). 



One hundred parts in weight of this gas contain the following 

 constituents : — 



Carbon .... 63*S6l 11*21 hydrogen in excess above 

 Oxygen . . . 22*01 > 24*92 parts of water reduced to its 

 Hydrogen.. 14*13j elements 



100*00 



The volume of hydrogen gas in excess above the elements of 

 water, both in alcohol, ether, their gaseous products, and in ole- 

 fiant gas, is equal to the volume of the carbonic acid gas produced 

 by each of these substances during its combustion. 



We may in consequence of this property, or of the ratio of three 

 to two mentioned above, establish the proportion of the three 

 elements which constitute the known weight of alcohol or ether, if 

 we have any one of the three following data : — 1. The hydrogen in 

 excess above the elements of the water. 2. The oxygen consumed 

 during the combustion. 3. The acid produced during that process. 



Since alcohol is represented by olefiant gas united to a quantity 

 of water equal to about haif the weight of that gas, while ether is 

 composed of olefiant gas united only with water amounting to one- 

 fourth the weight of that gas, and since olefiant gas contains no 

 water, we see what is the action of sulphuric acid on alcohol to 

 form either ether or olefiant gas. In both cases it merely abstracts 

 the water essential to the alcohol. When we mix this last liquid 

 with about its own weight of sulphuric acid, we employ only the 

 quantity of acid necessary to abstract one-half of the water essential 

 to ether, and we obtain ether. When we mix alcohol with four 

 times its weight of sulphuric acid, we add a sufficient quantity to 

 deprive it of the whole of its water, and then, instead of ether, 

 olefiant gas is obtained. 



A certain portion of the alcohol destined to these operations 

 appears, in consequence of the too energetic action of the acid, to 

 undergo a farther decomposition towards the end of the distillation 

 than is necessary either for the production of ether or olefiant gas. 



