1893. ] Microscopy. 407 
The plan in general, is the same as in the complete form illustrated in 
Plates VI and VII. 
Method of operation. 
Thoroughly dust the inside of the case and partly, or completely, 
fill the compartments with clean slips and cover-glasses of the proper 
sizes and place the warnings in position. The apparatus is then ready 
for immediate use, or at any time during successive weeks or months until 
the stock of slips and covers is exhausted. 
The slips are withdrawn from the case singly by pulling forward 
the mounting table, and from this they are removed, either before or 
after an object is mounted, by inserting a finger into the notches cut 
into the sides of the table. The mounting table is automatically 
reloaded on being pushed back into the case. The warning slip having 
been withdrawn, the service compartment is again filled by removing 
the sliding cover which carries with it the cover-glass case, withdraw- 
ing a loose partition and sliding the cleaned slips from a stock com- 
partment into the service compartment. 
Whenever a cover-glass is needed, the dust-excluder in front of the 
proper slot is opened by a touch of the finger, the milled wheel is 
- rotated and the chamois covered roller pushes the bottom cover-glass 
through the slot and out upon the grooved table, where it is readily 
grasped by the forceps. This action is positive because the friction 
between chamois and glass is greater than between two clean glass 
surfaces. The table being grooved, only the extreme margins of the 
cover-glass touch it. A touch of the finger closes the dust-excluder. 
It will be noted (a) that the slips and covers are doubly protected 
from atmospheric impurities by the dust-proof case and the constant 
contact of clean glass surfaces with each other; and (b) that in the 
process of removal for use they do not come in contact with any sur- 
face from which they receive dust. They come out as clean as when, 
weeks or months before, they were put into the case. Thus the dust 
problem is solved—A. H. Cons, A. M., University of Chicago. 
Cooling Paraffine.—To those who have experienced the incon- 
venience and difficulty connected with the preparation of good par- 
affine sections in the Tropics or even in the Tropical Summers of other 
climates, the following mee device of Professor C. Gracomini' may 
be a welcome suggestion 
1Arch. Ital. de Biolegie, IX, 1888, p. 380. 
