ch.viii.] ORGANIZATION OF THE SCIENCES. 80S 



only the science of weight, but also the sciences of heat, 

 light, electricity and magnetism, to say nothing of sound. It 

 was incumbent on Comte to show that this whole group of 

 phenomena became scientifically coordinated at an earlier 

 date than the phenomena of chemical composition and 

 decomposition. This, however, it would have been impos- 

 sible to show. Electric phenomena, the most backward of 

 the group, were not scientifically coordinated until the 

 close of the last century, when Coulomb generalized the laws 

 of electric equilibrium. Strictly speaking, there was no 

 general science of Physics even when Comte wrote the 

 " Philosophic Positive ; " and in linking together the allied 

 departments of optics, thermology, acoustics and electrology, 

 he made up what was then an incongruous group, about 

 which it was unsafe to make general statements. In 1842 — 

 the year in which Comte's work was finished — Mr. Grove, by 

 showing that the different allied manifestations of physical 

 force are modes of motion which are convertible into each 

 other, laid the foundations of a general science of Molecular 

 Physics, regarded as a science of vibrations. And in 1843 

 Mr. Joule, by discovering the mechanical equivalent of heat, 

 gave to the new science a quantitative character. These 

 were the great epoch-making steps, like the steps taken by 

 Newton in astronomy, which founded the science. 



It is thus evident that Comte was far from successful in 

 this part of his classification ; and considering the state of 

 •cience forty years ago, it appears impossible that he should 

 .Lave succeeded. He united phenomena which should 

 have been kept separate, and separated phenomena which 

 should have been united. We are now in a position to see 

 that Conne s grand division of inorganic science must be 

 subdivided into Molar Physics, which treats of the move- 

 ments of masses ; Molecular Physics, which treats of the 

 movements of molecules and of the laws of aggregation ot 

 homogeneous molecules; and Chemistry, which treats of the 



