USEFUL MICROSCOPE ACCESSORIES 



121 



FIG. 65. Reagent Bottle with 

 Barnes Pipette. (X f.) 



FIG. 66. Ebonite Tubes for Ammonium 

 Fluoride. 



Glass Rods and Pipettes. The tiny amounts of reagents 

 required for microchemical tests are most conveniently removed 

 from bottles and vials by means of drawn-out glass rods or 

 by platinum wires mounted in a glass handle. The type of glass 

 rod found to be most useful is shown in Fig. 67; if one or two 

 millimeters of the drawn-out end are slightly roughened with a 

 piece of fine carborundum or emery cloth, or ground on a wheel, 



FIG. 67. Drawn-out Glass Rod and Platinum Wire for handling Reagents. 



it will be found that both liquids and solids are more easily trans- 

 ferred and handled than if the glass be smooth. Slightly breath- 

 ing on the end of the rod, or touching it to one's fingers before 

 bringing it in contact with the reagent will cause tiny fragments 

 of dry powders to cling to the rod long enough to permit all usual 

 transfers. Similarly, roughening the end of the platinum wire 

 improves its carrying power. Rods and wires roughened, neces- 

 sarily require more care in cleaning after use than when polished. 



