^jTm^nL.SirOm'] ^ Dissecting Microscope. 347 
polished thereon by hand movement ; generally not more than two 
or three applications of the powder are required. I have tried this 
method with the identical paper and polishing material, but must 
state that in niy hands the result has not been satisfactory for 
accuracy, at least in very small prisms ; for larger ones it may 
answer better. 
(To he continued.) 
III. — A New Universal Mounting and Dissecting Microscojoe. 
By W. P. Marshall, President of the Birmingham Natural 
History and Microscopical Society. 
This instrument consists of a convenient arrangement of dissecting 
microscope, combined with a complete set of apparatus for mounting 
microscopic objects, and a compound body is added, forming a 
student's microscope for general use ; the whole being contained in 
a compact portable case, which when set open exposes all the 
contents conveniently for access. The object in the design has been 
to supply a want that has been felt, of a mounting apparatus con- 
taining in a single small case everything that is ordinarily required 
both in the examination and the preparation for mounting of micro- 
scopic objects ; and thus affording the means of readily and con- 
veniently securing upon the spot any objects found in the country 
or at the seaside, that would be deteriorated in microscopic value or 
lost altogether if their mounting had to be deferred until returning 
home. The whole apparatus is also very convenient and complete 
for mounting work at home. 
The microscope has three simple lenses magnifying separately 
or in combination from 6 to 20 diameters, and a dividing objective 
of 45 and 90 diameters, with the means of adding any higher 
objectives from another microscope, the nose being made with the 
standard screw, and space allowed in the case for packing other ob- 
jectives. The mounting apparatus includes a turn-table, hot-plate 
with spuit-lamp and dissecting-trough, with forceps, dissecting-knife, 
needles, dipping-tubes, &c., and a stock of mounting materials in 
fifteen bottles, with glass-slides and cover-glasses, &c. The whole 
is fitted into a compact case about seven inches cube, and arranged 
so that all the contents are at once accessible for use, and quickly 
repacked. 
The microscope-stand is fitted with rack adjustment for focussing 
mirror, side-condenser, and stage-forceps ; and when fitted with the 
compound body the stand has a movement into an inclined position. 
VOL, I. 2 b 
