ACCESSORY INSTRUMENTS. 



135 



sary, the entire quantity must be dropped into a watch glass, 

 which spreads it, and the insect may be again caught by 

 putting the tube over it, when a small quantity of fluid is 

 sure to run in by capillary attraction ; 

 this small quantity is to be placed upon 

 the tablet ; but should there be still foo 

 much for the tablet, if it be touched 

 with the tube again, it wUl be diminished ; 

 and should the object be wanting, the 

 fluid must be wiped off, and the opera- 

 tion repeated until we are satisfied of its 

 presence. 



If we wish to place several individuals 

 together on the tablet, it is necessary that 

 each should be taken up with the smallest 

 amount of water; to effect this, Mr. 

 Varley suggests that the tube should be emptied on a slip of 

 glass, in separate drops, as in fig. 8 8, and with one of the capillary 

 tubes, but little larger than enough to catch them, they may be 

 lifted out one by one, and be placed on the tablet. Generally 

 speaking, it is necessary to add a small quantity of vegetable 

 matter to animalcules to keep them alive ; and as many 

 species of them are found on confervas and duck-weed, some 

 instrument is required to take small portions of these plants 

 out of the jar in which they are growing ; for this purpose 

 Mr. Varley has contrived the forceps represented by fig. 89 ; 



Fig. 88. 



Fig. 89. 



they are made of brass or German silver, with points a little 

 curved ; to keep them accurately together, they are provided 

 with a hole and steady pin. Being thin and easily closed, they 

 answer very well to put into a phial and take out small portions 

 of vegetable matter; but when jars, such as those in which 

 chara or vallisneria are kept, are deep, then the long forceps. 



