518 THERMOTICS. ATMOLOGY. 



tensively assented to, certain general views, each 

 of which explains its appropriate class of pheno- 

 mena; and, in some cases, these principles have 

 been clothed in precise and mathematical condi- 

 tions, and thus made bases of calculation. 



These principles, thus possessing a generality of 

 a limited kind, connecting several observed laws 

 of phenomena, but yet not connecting all the ob- 

 served classes of facts which relate to heat, will 

 require our separate attention. They may be 

 described as the Doctrine of Conduction, the Doc- 

 trine of Radiation, the Doctrine of Specific Heat, 

 and the Doctrine of Latent Heat ; and these, and 

 similar doctrines respecting heat, make up the 

 science which we may call Thermotics proper. 



But besides these collections of principles which 

 regard heat by itself, the relations of heat and 

 moisture give rise to another extensive and im- 

 portant collection of laws and principles, which. I 

 shall treat of in connexion with Thermotics, and 

 shall term Atmology, borrowing the term from the 

 Greek word (ar/mos,) which signifies vapour. The 

 Atmosphere was so named by the Greeks, as being 

 a sphere of vapour; and, undoubtedly, the most 

 general and important of the phenomena which 

 take place in the air, by which the earth is sur- 

 rounded, are those in which water, of one con- 

 sistence or other (ice, water, or steam), is concerned. 

 The knowledge which relates to what takes place 

 in the atmosphere has been called Meteorology, in 



