CONSTITUTION OF LIQUIDS. 141 



alcohol is composed of 3 atoms hydrogen, 2 of 

 carbon, and 1 of oxygen while water is com- 

 posed of 1 atom hydrogen to 1 of oxygen. Hence 

 the difference between their specific gravities and 

 boiling points the specific gravity of pure aether 

 being about -700, and that of alcohol -794, com- 

 pared with water 1000, which congeals at 32 F. 

 while aether and alcohol are exceedingly difficult 

 to congeal.* 



That light and volatile liquids contain more 

 caloric than water and some others which are 

 more dense and tenacious, might be inferred from 

 the large amount of hydrogen which they con- 

 tain, and from their highly combustible property. 

 So highly inflammable is aetherine, that it takes 

 fire on the first approach of a lighted taper. 



It has been often stated gravely by chemical 

 writers, that cold results from evaporation, because 

 vapours have a greater capacity for caloric than, the 

 liquids from which they are formed, but this is 

 mere verbiage, and does not explain how liquids 



* It was said that alcohol had been frozen by Hutton; and 

 Fourcroy supposed that he had frozen aether at 46. But neither 

 Thenard nor Bussy were able to congeal it : from which it is pro- 

 bable, as observed by Mr. Brande, that the aether employed by 

 Fourcroy was not pure. It is now certain however from the ex- 

 periments of Thilorier, that both may be congealed. 



When alcohol and water are mixed, they combine chemically, 

 with diminution of their aggregate volume and disengagement of 

 heat. Proof spirit is composed of about equal weights of each, 

 the specific gravity of which should be -916. 



