248 THE APPLICATIONS OF PHYSICAL FORCES. [BOOK in. 



To give an idea of the immense services rendered to science by 

 the microscope, to initiate the reader, who has not this valuable 

 instrument at his disposal, into the wonders of the world of the 

 infinitely small, we reproduce in coloured Plates some specimens of 

 objects seen with the microscope, taken from the three great branches 

 of natural bodies animal, vegetable, or mineral. We are indebted 

 for these beautiful plates to the kindness of M. Georges Pouchet, 

 sub-director of the Histological Laboratory, directed by M. Robin, 

 and t6 the skill of an able draughtsman, M. Deyrolle. 



