1895 THE MICROSCOPE. 155 



bubbles and the job is spoiled. Next take auother dip 

 on the wire and drop it on the object in the cell, this will 

 fill an ordinary cell (the amount of liquid carried over, 

 that is the size of the drop, depends on the size of the 

 wire and the depth of the liquid in the bottle) full to the 

 edges and much fuller at the center, as it will take a 

 spherical form ; next place a clean cover on the medium 

 centrally, and allow it to fall down by its own weight. 

 Should it not do this, then gentle pressure may be used 

 on the center of the cover ; be in no hurry, go slow, and 

 when the cover is down fair and square on the cell, put 

 on a spring clip and with a wooden needle holder handle, 

 or some other similar tool, press the edge of the cover 

 down into close contact with the top of the cell. 



Clean off by absorbing the su2:)erfluous medium with 

 bibulous paper. Take off the clip, place the slide on the 

 turn-table, put a conical rifle bullet on the cover ce7i- 

 trally, for a weight, then with camel's hair pencil and 

 water, wash all around the cover, clean, dry with bibu- 

 lous paper; then with camel's hair pencil and alcohol, or 

 benzol, brush around the cover, this is to absorb all 

 moisture, then with hot paraflSne spin a seal ring of par- 

 aflBne around the juncture of cover and cell and when this 

 is cool and hard, the mount may be finished in the regu- 

 lar way, labelled and placed in the cabinet a "thing of 

 beauty" and a "joy forever." 



Interesting Little Aeronauts. 



By prof. B. B. KNERR, 



ATCHISON, KANS. 



The spores of the common horsetail (Equisetum ar- 

 veuse) are exceedingly interesting little aeronauts. If 

 the tip or cone of a ripe fertile frond be struck against 

 a glass slip a shower of white dust will be observed to 

 fall out. Place this just as it is without a cover under 

 a half inch or inch objective and the dust will be seen 



