INTRODUCTORY REMARKS. 19 



the vast perfection to which the telescope in more recent 

 times has been brought ? I need only mention the dis- 

 covery of the aberration of light ; the resolution of 

 nebulae and of the double stars j the motions of these 

 binary systems, and their subservience to the same law 

 of gravitation as governs the solar ; the position and 

 direction of the latter in space: I might mention many 

 others, all equally important all marvellously grand ! 



And so with respect to the Microscope in aiding to ex- 

 tend our knowledge of the economy of this planet. Every 

 improvement in this instrument has developed some im- 

 portant feature in the structure and design of the almost 

 infinitely varied organized beings of our earth. The 

 achromatic principle, which was at once adapted to the 

 telescope with the most astonishing success, did not 

 produce the same happy result on its first application to 

 the microscope. The recent discovery of Dr. Goring, 

 that the penetration of this instrument was dependent 

 upon the angle of aperture, or the number of rays of 

 light collected by the object-lens from every point on the 

 surface of the object, was requisite for the accomplish- 

 ment of this desirable purpose. By thus applying the 

 achromatic corrections and those for sphericity to this in- 

 strument, it has now been perfected, and elevated to a 

 grade nowise inferior to the telescope. The fruits of 

 this discovery are fast pouring in upon us, and promise 

 to yield a rich and most abundant harvest. We will al- 

 lude cursorily to some of those which have been reaped 

 already ; a few only will suffice to shew their importance, 



