74 



OSMOTIC PRESSURE OF AQUEOUS SOLUTIONS. 



doors behind it may be exposed to view. With these arrangements, 

 and with artificial illumination by screened lamps, it is practicable to 

 observe objects in the bath with very little exposure of the interior. 



Figure 41 shows the external appearance of the circular bath, and 

 Figure 42 the appearance of the interior when a portion of the outside 

 is removed. 



Hff^ ** 



■ m 



Fig. 41. — Exterior view of bath for high temperatures. 



Fig. 42. — View between interior and exterior baths, i. e., of space filled with water. 



Figure 44 is a horizontal section of one of the larger baths of Type IV. 

 Like the smaller ones, they are used for the measurement of osmotic 

 pressure, and also for all of the purposes for which the so-called "man- 

 ometer house" was formerly employed — such as the determination of 

 capillary depression, the determination of nitrogen volumes, the com- 

 parison of manometers, etc. It is elliptical in form, the longer axis 

 being twice the diameter of the compartment (A) in the smaller baths. 

 It is also higher than the circular baths by 100 millimeters, giving a 

 height of 1.1 meters for A. It has three pumping tubes (C, C, and C) 

 instead of two, and 8 or 12 lamp compartments (L, L, L, and L) instead 



