PHOTO-MICROGRAPHY. 



CHAPTER I. 



INTRODUCTION. 



BEFORE beginning a detailed description of the 

 apparatus employed in Photo- micrography, a few 

 remarks are necessary on its utility in research, and 

 its"application to the various branches of science. 



All microscopists are aware of the fickleness with 

 which objects display their structure, markings 

 easily perceived at one time may baffle all attempts 

 to resolve them at another, and perhaps when seen 

 are beyond our power to delineate, I have before me 

 at present, some drawings which must have taken 

 the artist a week to finish, and even then, shew the 

 existence in his mind of preconceived notions of 

 their structure. 



Photography not only obviates the necessity of 

 future trouble and perhaps failure in the display of 

 these markings, but in a period varying from a few 

 seconds to as many minutes, imprints the latent 

 image on a sensitive surface, which after develop- 

 ment, can be multiplied a thousand fold, and give to 

 the world results, indisputably proving the truth of 



