674 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Fig. 
i3) Illuminating- and other Apparatus. 
New Thermostat heated without the use of Gas. 3 " — Dr. W. Kara- 
waiew gives a detailed description of the thermostat which he has found 
very serviceable for histological purposes. The regulator for the thermo- 
stat depends in its construction upon a new principle, viz. the cutting off 
from the thermostat of the heat of the flame by means of a rotating metal 
plate. In fig. 95, A B C D represents 
the section of the thermostat and EFG 
that of the plate, at right angles to 
the axis of rotation which passes through 
F and is parallel to the edge of the ther- 
mostat from front to back through C. At 
first tho position of the plate is such 
(E F G) that the heat of the flame F l acts 
without hindrance on the bottom of the 
thermostat C D. This will be the case 
until the temperature of the thermostat 
rises above a certain point, when the plate, 
by an automatic arrangement to be cx- 
Fig. 95. 
plained later, moves into the position K F L, and the heat of the flame 
is cut off from the thermostat. 
The thermostat consists of a cubical copper box with double 
walls, the interval between which is filled with water. As source 
of heat the author uses the benzine lamp of Pusclikareff. The in- 
ternal construction of this lamp is seen in half natural size in fig. 96. 
The brass tube of the lamp has a length of 21 cm. Its upper part a is 
* Zeitschr. f. wiss. Mikr , xiii, (189G) pp. 172 -83. 
