, MICROSCOPY. 705 
of Mr. Henry George and Mr. Piper. The cabinet may be fur- 
nished, at the bottom, with some deep drawers for the reception 
of large objects in deep cells; the heavy objects thus brought 
together being represented in the classified collection by blank 
slides properly numbered and labelled, and referring to the drawer 
in which the object is to be found. Slides not exceeding three 
inches square are easily arranged in the regular drawers, and if 
any exceed three inches they should still be placed in their proper 
position, the partitions being cut away so as to allow them to occu- 
py a double interspace. 
A Lire Stipr.—The accompanying engravings represent front 
= and side views of a form of life slide for the microscope, designed 
4 and used with much success by Mr. D. S. Holman. It is con- 
structed to retain the greatest quantity of material under the 
smallest cover glass, and is designed to be used with the highest 
powers of the microscope for studying the Bacteria, Vibriones, 
and other very low forms of life. 
The slide consists, as will be seen from the cuts, of a central 
polished cavity, about which is a similarly polished bevel ; and from 
the bevel outwards extends a small cut, the object of which is to 
afford an abundance of fresh Fig. 143. _ 
air to the living beings within, | 
as well as to relieve the pres- Soe 
sure, which shortly would be- 
as to cause the destruction of 
the cover glass. i 
= No special dimensions are 
stated for the central cavity. ny 
The bevel is usually 4 inch in diameter (the cut is 3 of natural. 
size) ; the small canal is cut through the inner edge of the bevel 
or annular space, outwards, for the purpose named above. 
_ Tt is found, upon enclosing the animalcule, etc., that they will 
învariably seek the edge of the pool in which they are confined, 
and the bevelled edge permits the observer to take advantage of 
this disposition ; for when beneath it, the objects are within range 
(Of the glasses of high power. 
a Another very important feature in the device is the fact that a 
_ AMER. NATURALIST, VOL. VI. 5 ; 
nn 
