510 MICROSCOPY. 
ure will be entered under several headings and be used to illus- 
trate all these points, while under the usual methods of classifying 
slides in series, a number of duplicate slides would be required to 
fill up the different series. All difficulty in finding specimens is 
also positively obviated. 
The president, Mr. Jabez Hogg, expressed the belief that the 
proposed plan would supersede all others now in use. 
Sanp-sLast Cetts.— Mr. Henry F. Hailes contributed to the 
Queckett Club an account of a new and probably valuable appli- 
cation of the sand-blast process. It had occurred to him that this 
process might be employed to sink cells in glass slips for micro- 
scopical mounting ; and he applied to the inventor, Gen. Tilghman, 
who had a supply sunk in an apparently satisfactory manner. Mr. 
C. Baker, the optician of High Holborn, has undertaken to sup- 
ply these new cells to the trade. They can be sunk of any de- 
sired size and shape, and possess the positive advantage of having 
no joint at the bottom of the cell. Of course the floor and sides 
of the cell are rough or “ ground ” surfaces, but this is not a seri- 
ous disadvantage. For opaque objects the ground surface fon 
an agreeable background; for objects in balsam, the refractive 
index of the medium corresponds so nearly with that of glass that 
the granulations of the glass surface are optically obliterated and 
disappear entirely ; for media of less refractive power than bal- 
sam, it is necessary to varnish first the ground surface with per 
and allow it to dry before introducing the fluid. The none 7 
seem particularly available for foraminifera, insects haer à : 
without flattening, and other clumsy specimens, whether 1m air or 
balsam or glycerine. 
AxorTHER MiıcroscoricaL Cement. — Mr. T. Charters „e ; 
recommended to the Queckett Club four or five parts of this 
yellow beeswax melted with one part of Canada balsam po ; 
purpose. Like the electrical cement, and the paraffine, which i 
already come into general use for the same purpose, it 1$ 5008 
melted, on a hot wire, after the manner of soldering; sels 
as cool, and hence cannot run in under the cover however e 
cell may be, and can be instantly loosened by warming if Iti 
is to be repaired or the object dismounted for any pare we 
especially applicable to dry mounting, to temporarily = a 
jects for early use, and to fasten apparatus where Contry? 
