THE MICROSCOPE. 139 



very delicate, through a cork that has been rudely squared so as 

 to afford a finger-hold and to serve as a guide for the proper 

 position in which to hold the blade. Holding the latter, edge 

 downward, on the stone, move it lightly backward and forward 

 with a scraping motion until you wear off sufficient metal. 

 Examine, from time to time, to see whether you are getting the 

 proper shape to the point. Repeat the operation with the back 

 of the knife downward. After you have sharpened the blade on 

 the rough hone you can sharpen the curved edge of the point. 

 Beginners had better replace the cork for this operation, leaving 

 just sufficient of the blade exposed to rest firmly and smoothly 

 on the hones. If there are gaps along the edge remove these, too, 

 before beginning to sharpen. This is done by holding the edge 

 perpendicularly on the stone and scraping backward and for- 

 ward until the entire edge is worn back to the depth of the gap. 

 This keeps the edge true and straight. 



It sometimes happens that one wishes to use a bottle in a 

 great hurry, and a clean, dry one is not at hand. If you wash 

 out a bottle in the ordinary way, it takes a good while to dry 

 completely. If you want to put, say a solution of dammar, or 

 benzol, or zinc cement into it, it must not have a single drop of 

 moisture in it. I will tell you how you can use it in a half min- 

 ute after rinsing. Shake out all the water that you can get 

 rid of by swinging the bottle, mouth downward, to and fro. Then 

 go to your alcohol jar, fill your bottle quite full of alcohol, and 

 pour it back into the jar. The residual drop or two of water will 

 not materially lower the strength of your stock. Shake out the 

 few residual drops of alcohol and repeat the same operation 

 with absolute alcohol, returning the latter to your stock. Then 

 if you are very particular, you may proceed in the same way, 

 using benzol as a rinser. The bottle is then clean, ready to be 

 filled. The same process may be followed with a sable pencil, 

 a costly brush or article of that sort that has been used in an 

 aqueous medium, and you wish to transfer it at once to an 

 enamel or cement bottle. Wash it in water to get rid of the 

 medium, rinse first in water, next in alcohol, then in absolute 

 alcohol, and finally in benzol. If it has been in some gummy or 

 oily material and you wish to use it in an aqueous or other me- 

 dium, wash it with the liquid soap described above, rinse with 

 clear water, and it is ready for use again. — National Druggist. 



