274 



give equal volumes of vapours, calculated by the expression 



x = — already given, the values of s and s being taken from 



the third column. 



1. 2. 3. 



Specific Gravity 



referred to air at 



Boiling points. 



Water, . . 

 Wood Spirit, 

 Alcohol, . 

 Ether, . . . 



.622 

 1.120 

 1.613 



2.586 



Specific gravity 



at Boiling points 



referred to air 



at 60°. 



.480 



.950 

 1.322 

 2.397 



4. 



Weights, giving 



equal volumes 



of vapour. 



1.000 

 1.979 

 2.754 

 4.993 



" It is now easy to assign the quantities of caloric necessary 

 to produce an equal volume of the vapour of each liquid at 

 their respective boiling points, for these will obviously be re- 

 presented by the expression 



mc {(t-50) + I) 

 m being for each liquid its number in column 4, c its specific 

 heat, t its boiling point, and I the latent heat of its vapour at 

 the temperature of ebullition. When, with the aid of the an- 

 nexed Table, — 



Boiling Points. 



Specific Heats. 



Latent Heats. 



Water, . . 212° 



1.00 



961.8 



Wood Spirit, 151.7 



.67 



475.2 



Alcohol, . . 172.4 



.64 



374.4 



Ether, . . . 100.4 



.50 



163.8 



which exhibits the specific and latent heats on which most re- 

 liance can be placed, the numerical calculation is made, the 

 following are the results : — 



Water, . . . 



1129 



1.000 



Wood Spirit, . 



764.8 



.676 



Alcohol, . . . 



875.5 



.775 



Ether, . . . 



534.7 



.473 



