Cr 



Manometer 



Flotation 

 nnediunn 



Zero line 

 Diver 



Flotation medium 

 (lithium chloride) 



Gas space 

 total vol. 

 about 24X 



2X 



Holtfreter solution 

 Tissue 



Glass tail 



"U Fine adjustment 



-|J Coarse adjustment 



Figure 11-39. Schematic Diagram of Cartesian Diver Micromanometer. 

 (A) Diver vessel with diver suspended in flotation medium (concentrated 

 lithium chloride solution). The diver vessel is connected to a water manom- 

 eter, the pressure in which can be adjusted by a coarse and fine syringe 

 mechanism (bottom). (B) Details of Cartesian diver. The tissue is placed 

 in 2 X ( 1 X = 1 cu. mm.) of physiological medium at the bottom of the diver 

 bulb which has a glass tail to maintain the diver in a vertical position. The 

 neck is partly occupied by a drop of oil, so placed that there is a small bubble 

 of air between the oil and the flotation medium. A reading is taken by bring- 

 ing the diver to a temporary standstill at the zero line and noting the pressure 

 level in the manometer. (From Boell, E. J., Needham, J., and Peters, V., 

 1939. "Morphogenesis and Metabolism: Studies with the Cartesian Diver 

 Ultramicromanometer. 1. Anaerobic Glycolysis of the Regions of the Am- 

 phibian Gastrula," Proc. Roy. Microscop. Soc. {London), 127, Fig. 1, 

 p. 326.) 



SURVEY OF CYTOLOGICAL TECHNIQUES / 263 



