OP THE MICROSCOPE. 



169 



SLIDE HOLDER. The hot slides cannot be comfortably held 

 in the fingers, and therefore a pair of wooden forceps become 

 a necessity. Those usually sold are made by screwing together 

 two thin slips of wood with a piece of brass or lead inserted be- 

 tween them at one end. To admit the slide, the slips are forced 

 apart by pressing on pins arranged as in the stage forceps. 

 When placed on a table the 

 metal counter-balances the slide, 

 and keeps it from touching the 

 surface on which it is laid a 

 very important point. The Eng- 

 lish forceps, being all wood, fre- 

 quently tip with a heavy slide. 



A common spring clothes-pin 

 is frequently used, but when we 

 come to lay the slide* down, the 

 clothes-pin holds it in an awk- 

 ward manner. The end of the 

 hot slide is sure to lie on J;he table, 

 and if fluid balsam or other me- 

 dium should be present, the fact 

 that the slide is not level produces 

 bad results. By cutting off about 

 half an inch from one of the 

 limbs of the forceps part of the 

 pin, however, this difficulty is 

 avoided. The slide may then be 

 grasped in such a way that when 

 the clothes-pin is placed on the 

 table, the glass will be held in a 

 perfectly level position. A glance 

 at Fig. 45 will show what we 

 mean. A great advantage of this 

 form of holder is that it costs but a trifle, so that the micro- 

 scopist can supply himself with an abundance of them, and 

 thus several slides may be cooling, while work on others i ; 

 going on. When very heavy slides are used, it may beconi" 

 necessary to screw a plate of sheet lead to the under side of tlu 

 clothes-pin, so as to prevent tipping. 



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