PART VI. 

 TECHNICAL MICEOSCOPY. 



I. 



THE USE OF THE MICKOSCOPE. 



IT may be assumed, as a matter of course, that the various 

 information regarding technical methods and contrivances which 

 is presupposed in microscopical observation, may always be learnt 

 most easily by practical instruction, and that individual skill, 

 which the beginner gradually acquires, is always the main point. 

 A short introduction, however, may not be superfluous, since it 

 will afford some compensation to those who have not had 

 sufficient of this practical training, or who may even lack the 

 training altogether, and may enable them to avoid many errors 

 of judgment. Everything relating to special researches in the 

 departments of Anatomy, &c., and to the use of reagents, &c., we 

 shall postpone to separate chapters under these headings, and here 

 discuss only a few of the more general questions. 



1. ILLUMINATION. 



For every microscopic investigation a favourable illumination is 

 very important. As the illumination is partly dependent upon 

 the situation of tJie laboratory, this should be so chosen that a large 

 portion of the sky may be employed as the source of light, without 

 direct sun-light. The most convenient is, of course, a room with 

 north light and free prospect, or a room with windows on two 

 sides, in which either side can be used according to the position of 



