20 



THE MICROSCOPE. 



r.Fannarw 



L t/ 



In many cases these objects have been stained, either singly or 

 doubly, and some stained three years ago have not faded. 

 Their very low cost commends them to every student of biology 

 or collector of microscopic objects. 



Directions for Mounting. — They may be mounted in resin- 

 ous media (damar, benzol-balsam), glycerin, or glycerin jelly, 

 the former being the easier for a beginner, while the hitter, 

 though more trouble, shows structure better. 



In mounting, carefully separate the films, and remove the 

 object. If for resinous media, soak in spirit of turpentine till 

 clear, rinse in a fresh portion of the same, then drain, transfer to 

 the slide, and finish as usual. For glycerin : If the object be 

 oily, first wash out the oil with strong methylated spirit, transfer 

 to glycerin and water, equal parts. Let it remain an hour or 

 two, then mount. Minute objects, such as isolated cells, should 

 be transferred on the point of a scalpel to a slide (or cover), and 

 separated with a needle in a drop of spirit ; then, if for glycerin, 

 mount while still moist ; but if for resinous media, allow to dry, 

 then moisten with a drop of turpentine before applying the 

 medium. Spiral and other vessels, and long fibre cells, which 

 mat together, should be soaked in a drop of weak spirit, and a 

 few of the most perfect picked out under a simple lens. 



