OBJECT SLIDES 



149 



blow or two with a hammer, filed to a double chisel edge and 

 polished, thus giving an instrument useful in breaking up small 

 fragments of soft salts, or in loosening reagents in the set of vials 

 referred to above. 



FIG. 83. Forceps for Microscopic Work. (Full size.) 



Forceps. For picking up tiny fragments of dry material, 

 handling cover glasses, small watch glasses, etc., forceps (Fig. 

 83) with fine curved tips are indispensable. The corrugations 

 usually found on the points should be carefully filed away until 

 the tips are almost smooth. 



When deliquescent or corrosive materials are to be handled 

 the forceps should be provided with solid platinum tips, Fig. 84. 

 No microchemical outfit can be considered as complete without 

 platinum tipped forceps. Just as in the case above cited the 

 roughening at the tips should be carefully removed and at least 



FIG. 84. Forceps with Platinum Tips. (Full size.) 



one of the tips also filed flat and smooth on the outside, thus al- 

 lowing the tip to be used as a tiny spatula. Tips should be 

 sufficiently stiff and rigid to permit holding fragments firmly to 

 obviate all danger of dropping material or bending the tips. 

 Foil-like tips are for this reason an abomination since the slightest 

 excess of pressure causes them to bend and loosen. 



Object Slides and Other Supports. Object slides or slips 

 employed in microchemical analysis should be from i to 1.5 

 millimeters thick and made from glass of such composition as to 

 be as resistant as possible to the action of solvents. The color- 

 less glass object slides in common use in America, so excellent 

 for ordinary microscopic work, are easily attacked by all the 

 usual solvents and reagents employed in qualitative analysis. 



