800 



SUMMARY OF CURRENT RESEARCHES RELATINQ TO 



Babes' Hot Stage.* — In figs. 140 and 141 are shown different aspects 

 of Dr. y. Babes' hot stage for constant temperatures. By means of the 



two screws sch it is fas- 

 tened to the stage of the 

 Microscope or to Keichert's 

 movable stage. The hot 

 stage consists of a gnomon- 

 shaped box filled with 

 wat<ir or glycerin. The 

 preparation is slipped in 

 through the aperture o, and 

 it can be moved about. It 

 is warmed both from above 

 and below. The objective 

 and the Abbe condenser 

 are partly surrounded by 

 the box. Heat is imparted 

 by a thick copper wii-e k 

 heated in a gas flame. The 

 other end, which is within 

 the box, is convoluted. The 

 copper wire is insulated 

 from the sides of the box 

 by a layer of asbestos. 



The regulation is ef- 

 fected by means of an 

 electrical thermometer T 

 inserted in the same orifice 

 as that in which the pre- 

 paration is placed, and con- 

 sequently exposed to the 

 same temperature. The 

 wires of the electric ther- 

 mometer pass to the appa- 

 ratus shown in fig. 140, 

 which is supplied by a 

 small Leclanche battery. 

 By the movement of the 

 pole to a point previously 

 settled upon, the current is 

 closed, and the plate V 

 attracted towards the elec- 

 tro-magnets. This reduces 

 the stream of gas at Z, and 

 the flame is consequently 

 diminished. As the mer- 

 cury sinks, the valve Y is 

 again opened, and the gas 

 again flows through the 

 pipe Z to the jet. To the 

 thermostat there is also 



Centralbl. f. EakterioL u. Parasitenk., iv. (1888) pp. 23-5 (2 figs.). 



