1893.) Microscopy. 405 
MICROSCOPY. 
The Solution of the Dust Problem in Microscopy.—The 
statement of the dust problem is this: Given a stock of cleaned micro- 
slips and cover-glasses, to keep them clean and ready for use at any 
moment, without the necessity of brushing or wiping them. The fol- 
lowing solution is the result of a laboratory study of the problem, and 
is now announced after having received the approval of leading micros- 
copists, 
The objects to be accomplished are :— 
1st, To secure a dust-proof magazine for storing the cleaned micro- 
slips and cover-glasses in separate compartments for the different sizes 
of squares, circles, and oblon 
2d, To provide simple mechanical appliances for removing a single 
slip or cover without exposing those remaining in the case 
3d, To provide an automatic device for warning the operator of the 
approaching exhaustion of his stock of any of the shapes of covers and 
of slips, thus avoiding the necessity of opening the case except to replen- 
ish stock. 
4th, To provide against the breaki li g t of the covers 
iu case of the nocideutal ‘overturning ye the case 
5th, Incidentally to provide a mounting table with guides for center- 
ing the objects and cover-glasses, the whole apparatus being so con- 
structed that the glasses are not touched by the fingers, and only once 
by the forceps until the slide is completed and labeled. 
The Dust-proof Slip and Cover-glass Case” fully meets these require- 
ments. 
Plate VI is a front view of the case which is 4} inches square on 
the base and 6 inches high. The slips and mounting table are con- 
tained in the lower half and the cover-glasses in the upper portion. The 
mounting table is shown in position for work, and the concentric lines 
for guidance in properly centering the objects and covers are seen 
on the celluloid slip. Four dust-excluders are hinged to the front 
of the grooved table, and two of them are shown opened so as to expose 
the slots through which the cover-glasses pass out upon the grooved 
table. The milled head of the roller which pushes the cover-glasses out 
of the slots is shown at the side of the case. A screw stop is inserted in 
the front of the case above each slqt. 
1Ed. by C. O. Whitman, University of Chicago. 
2Patent applied for. 
