PREFACE. 



THE progress of modern science, especially within the 

 last few years, has been remarkable for a tendency to 

 simplify the laws of nature, and to unite detached 

 branches by general principles. In some cases identity 

 has been proved where there appeared to be nothing in 

 common, as in the electric and magnetic influences : in 

 others, as that of light and heat, such analogies have 

 been pointed out as to justify the expectation that they 

 will ultimately be referred to the same agent : and in 

 all there exists such a bond of union, that proficiency 

 cannot be attained in any one without a knowledge of 

 others. 



Although well aware that a far more extensive illus- 

 tration of these views might have been given, the 

 Author hopes that enough has been done to show the 

 Connexion of the Physical Sciences. 



