1883.] - Microscopy. 1315 
process of cutting: ` As seen in Fig. 3, the object, o, imbedded in 
a small piece of paraffine, is attached to a larger mass of paraffine 
contained in a hollow metallic cylinder. The cylinder, 7, may 
be slipped up or down in the cubical block, a, and turned around 
its longer axis by means of a small metallic rod applied in holes 
near its lower end (holes not seen in figure), The position of the 
cylinder may be fixed by the handle, 6, which works like the 
handle of a vise. 
The block, a, may be turned about the transverse axis of the 
frame which holds it, by the pinion d, and fixed by the screw e, 
the head of which is provided with holes for the metallic rod. 
In the same way the frame itself may be made to turn about 
its longer axis by means of the pinion g, and fixed by the 
screw f. : 
The chief merit of this holder lies in the fact that the object 
may be rotated very freely about the two axes of the frame, with- 
out at the same time being raised or lowered very much. This 
latter advantage depends on the fact that the axes of rotation are 
near the top of the block, a; 7.¢., as near the object as possible. 
The attachment of the object to a cylinder movable in a per- 
pendicular direction, has the great advantage that pieces of more 
than two centimeters in length may be sectioned. In order to 
obtain room for pieces of greater length, washers og Or 
thickness may be placed at first under the knife, and afterwards 
removed. 
ma (cf. NATURALIST, September, p. 993 ). The most recent 
improvement, according to Mayer, consists in making the so- 
called “points” of ivory, and the planes, on which the points 
rious friction. 
Prices of the Microtome and tts Adjuncts.— 
The older microtome, consisting of a stand of cast-iron and the 
two carriers, without the micrometer-SCreW ...++-++-+e5e%""* $24 00 
Same with ivory “ points” and new object-holder....-+++++++++"* 27 50 
The registering micrometer ScreW ......+++++ee0%* veeeucwoowues 10 00 
Knife for oblique cutting (16 long) with étui.....-++++++- Fo BO 
Knife for transverse cutting with étui, holder, &c..+..-++++++e+*** 8 00 
Beetonsswannther 6 fos resres uc aes ene eth ees Cores 2 25 
The complete set, including stand with ‘ planes ” of zinc and cop- 
per alloy and ivory “ points,” registering micrometer-screw, ve 
the two kinds of knives with étuis, and section-smoother pessas 55 $ 
This microtome can be obtained from the maker, Rudolph 
