248 



THE MICROSCOPE. 



out the chance of leaking, but it is rather difficult 

 to prepare, and, therefore, had better be bought. 

 A jelly composed of glycerine and gelatine equal 

 parts is very useful ; the glycerine 

 should be warmed, and the gelatine 

 (Nelson's) be allowed to dissolve 

 in it. 



Acetate of potash in a saturated 

 solution is used for some prepara- 

 tions, but is liable to leak. 



Injecting Small Animal Bodies. 

 For making injections it is essential 

 to have a proper syringe. One of 

 brass is the best, and of such a size 

 that the top of the thumb may 

 cover the button at the top of the 

 piston-rod when drawn out, while 

 the body is supported between the 

 two fingers. Fig. 143Z represents 

 the syringe, a is the body, with a 

 screw at the top for the purpose 

 of firmly screwing down the cover I after the piston c 



FIG. 143L Injecting 

 Syringe. 



FIG. 143;)i. Melting Vessel. 



is replaced ; e is a stop-cock, to the end of which either 

 of the smaller pipes g can be fixed. The transverse 



