ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
635* 
(3) Cutting-, including Imbedding and Microtomes. 
Koristka's Microtomes.* — The instrument with double slide repre- 
sented in fig. 74 is of cast iron nickeled. The razor runs on a horizontal 
slide-way, and the object-holder on a slide inclined at 1/20. The 
motion of the object-holder is by means of a micrometer screw with a 
divided head, which allows of the measurement of displacement of the 
object to be sectioned of 1/1000 mm. The micrometer screw can be^ 
displaced along the slide. The length of the slides is 26 cm. 
Fig. 76. 
The automatic microtome shown in fig. 75 has a stand of cast iron 
nickeled interiorly. The slide has a length of 25 cm., with a free course 
of the knife of 17 cm. The raising of the object is effected automati- 
cally by means of a micrometer screw and an escapement. The thinness 
of the sections can be regulated by a screw from 0*005 to 0*03 mm. 
The slide on which the knife is fixed rests on five points of tempered 
steel and moves with very slight friction. 
The freezing microtome (fig. 76) is of new construction. By means 
* F. Koristka, Catalogo Illustrate* Descrittivo, N. 7, Milan, 1894. 
