664 SUMMARY OF CURRENT RESEARCHES RELATING TO 
surface to be cut is raised, by means of the lever, up to the knife-edge. 
The removal of the paraffin is effected in the same way by means of the 
vertical displacement, but the cutting of the object itself is done exclu- 
sively by the use of the micrometer-screw. When the latter is turned 
to the end it is screwed back so as to bring the object-carrier into its 
original position, and the object is then again brought up to the knife- 
edge by means of the lever. 
The object-carrier is especially serviceable in all cases in which the 
object is to be sectionized only at intervals determined by the develop- 
ment of lateral organs. The micrometer-screw is then used for the parts 
to be sectionized, and the vertical displacement for the rest. There is 
an index at x for measuring the intervals between two of the lateral 
organs to be cut. The object-carrier represented in fig. 73 is of simpler 
construction, but is quite satisfactory for most purposes, and is to be 
recommended for use with the small model of the microtome. The 
movable metal-piece k supports the projecting object-clamp, and runs 
in a prismatic groove st. It rests on a screw-plate V, by the rotation of 
which its rise and fall are effected. A binding-screw a fixes it in any 
position. The rise, exclusive of the slide-way, amounts to 1 cm. 
New Heating Apparatus for Miner alogical Investigations.* — This 
piece of apparatus, designed by R. Briinnee, of the firm of Voigt and 
Hochgesang, in Gottin- 
gen, can be easily fitted 
to any Microscope. It 
serves to raise solid pre- 
parations or liquids to a 
high temperature, and, 
since the flame burns 
directly beneath the 
object-carrier, observa- 
tion can be made by 
polarized light during 
the heating. The appa- 
ratus has the following 
arrangement : — Beneath 
the object-stage B (fig. 
74) is a piece bored 
through in four places. 
Round the lower, coni- 
cally turned, part of the 
piece the arm A is fitted. 
The latter is movable on 
the cone, and is fastened 
to B by a screw c. Be- 
tween c and B a ring- 
shaped space o is left, 
winch is contracted internally to a fine slit. The gas and air required 
for the flame stream through the tub(s L and G (fig. 7b) into this space. 
The object-carrier B is provided with a row of outlets Lj. 1 he openings 
* Zeitschr. f. Iustrumentenk., x. (1890) pp. 68-4. 
Fig. 74. 
Fig. 75. 
