CONSTITUTION OF LIQUIDS. 139 



by the size of their proximate atoms, but by their 

 relations to a self-repelling fluid. 



There is a class of liquids which are composed 

 chiefly of hydrogen and carbon, that seem to 

 form a connecting link between gases and more 

 fixed bodies. They are generally much lighter 

 than water, and exceedingly volatile. Such are 

 Faraday's aetherine and bicarburet of hydrogen, 

 spirit of gum elastic,parafiine,and naphtha. jEther, 

 alcohol, pyro-acetic spirit, acetic aether, and most 

 of the essential oils, which are composed of car- 

 bon and hydrogen, united with small proportions 

 of oxygen, are lighter than water, and some of 

 them highly volatile. There are also a few com- 

 binations of hydrogen and carbon with nitrogen, 

 chlorine, and even iodine, that are very volatile, 

 as nitrous aether, hydrocyanic acid, muriatic, and 

 hydriodic aethers. There cannot be a doubt that 

 all such liquids owe their volatility to the same 

 cause which determines the elastic force of gases. 

 Accordingly, we find, that aetherine, the lightest of 

 them all, boils or expands rapidly into the gaseous 

 state, under the pressure of the atmosphere below 

 32. Common aether boils at 96, muriatic aether at 

 60, nitrous aether at 60, and acetic aether at 105, 

 while alcohol boils at 173.* Butwhen thepressure 

 of the atmosphere is removed, as under an ex- 



* With a view of ascertaining how far the rationale of such 

 phenomena had occupied the attention of philosophers, I took an 

 opportunity of asking a distinguished professor and author in 



