ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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dearer than the Naples water-bath, is more suitable for paraffin imbedding. 
The apparatus consists of a quadrangular box of copper (fig. 21), tinned on 
its inner surface. It is about 24 cm. broad and 26 cm. high, and it is 
divided by a horizontal partition into two compartments, the upper being 
10 cm., the lower 16 cm. high. In the upper one and in the lower are 
four spaces for the reception of drawers made of nickeled copper. 
The drawer-cases are supported by upright pieces. ‘On the top of 
the front of the box is a cupboard, behind which is a free space of 
10 cm. To the bottom of the cupboard and to the top of the box a sort 
of damper, in which is a double row of holes 15 cm. in diameter, is fitted. 
Fig. 22. 
At the top left corner are two openings, both of which communicate with 
the lower department, and through which it can be filled with water. 
In one is fixed a thermometer t 3 and in the other a gas-regulator. The 
level of the water is marked by a tube. At the bottom of the box 
is a tap for letting off the water. The thermometer t 2 , the end of which 
dips into a glass vessel filled with water, indicates the temperature of 
the cupboard, and that of the top drawer is given by t v Three tempe- 
ratures, with difierences of about 8° C., are obtained by this apparatus, 
and this is a desideratum in paraffin imbedding. 
Fig. 22 shows the subsidiary parts of the apparatus, and these are 
intended for the drawers and for the cupboard ; their use is too obvious 
to require description. One point in connection with the shape of the 
drawers, &c. may be alluded to and that is the sloping back and sides 
of the trays and drawers. This has some practical value, for when the 
paraffin has set it allows the whole lot of blocks to be taken out with 
ease. 
Cutting and After-treatment of Paraffin Ribbon Sections.* — Dr. 
G. C. van Walsem advocates the use of hard paraffin to which about 
5 per cent, of cera flava has been added for cutting sections with the 
Minot-Zimmermann microtome. To this instrument, which is preferred 
* Zeitschr. f. wiss. Mikr., xi. (1894) pp. 207-36 (4 figs.). 
