30 



THE STRUCTURE OF 



they may be viewed by transmitted light, very thin 

 sections of them should be made. This may be 

 effected by means of a very sharp scalpel, or a 

 razor. When objects are too small to be held 

 in the hand to be cut, they 

 may be placed between two 

 pieces of cork, and a section of 

 them made at the same time 

 that the cork is cut through. 



Sometimes it is found desir- 

 able to unravel an object under 

 the Microscope. If this is the 

 case, only a low power should 

 be used, and the object may be 

 placed on a glass slide, without 

 any glass over, and two needles 

 with small Wooden handles 

 employed, ordinary sewing 

 needles, with their eyes stuck 

 in t'le handle of a hair pencil, 

 \vill answer very well. (Fig. 14.) 

 Ev.-n when dissection is not 

 to be carried on under the 

 Microscope, a pair of needles 

 of this sort, for tearing minute 

 structures in pieces, will be 

 ' found very useful. 



When opaque objects are 

 to be examined, the light from 

 t ^ e mirror may be shut off, and 

 the aid of the bull's-eye condenser called in. The 

 object being secured in the forceps attached to the 

 stage (fig. 15), or laid upon a slide, the light is allowed 

 to fall on it through the condenser. (Fig. 9.) The 

 object-glass must be focussed in the same manner as 

 tor transparent objects, till the best distance is secured 



Fi 9- 14 - 

 Dissecting Needles. 



