356 



GASOMETRIC-MANOMETRIC METHODS 



and 121. The tongue on the left in Figure 121 moves on a horizontal 

 axis and presses the neck of the diver into a vertical V-shaped 

 groove in the head of the stationary post on the right. The edge of 

 the tongue is curved so that it touches the diver only at one point. 

 The tension needed to hold the tongue against the diver is derived 

 from a light spring which presses against the handle of the tongue 



3 cm. 



Fig.' ll'9. Diver support made of pressure tubing. 

 From Hotter (1943) 



(Fig. 120). The entire clamp is fitted on the top of a rack and 

 pinion stand, which enables the diver to be raised or lowered evenly. 

 The base of the rack and pinion stand has leveling screws so that 

 the inclination of the diver can be controlled. A mirror fitted to the 

 side of the stand enables the operator to observe the centering of 

 the pipette from the side, and a magnifying glass attached to the 

 front of the stand or used in a head band permits the operator to 

 observe more easily from the front. 



The diver is placed in the flotation vessel and removed from it 

 by means of a loop at the end of a piece of stainless steel wire 

 about 15 cm. long. The loop is made a little smaller than the diver 

 bulb so that the diver can rest on the loop with its tail hanging 

 down through the hole, and the loop is bent at right angles to the 

 wire so that the diver is upright when the wire is held vertically. 



(7) THE PIPETTES 



The pipettes used with the divers are straight glass capillaries 

 designed to measure 0.2-2 /xl. volumes with an accuracy of 1%. 

 They are filled and emptied by mouth through a piece of rubber 

 tubing. Four types of pipettes are used with microliter divers. 



