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 the handle of a hair pencil, 

 will answer very well. (Fig. 14.) 

 Even 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 

 the 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 for transparent objects, till the best distance is 



