.VOLUME MEASUREMENT 



433 



4. Transfer the object to a fresh flat drop of the dye soln. 



5. Draw the object up into the capillary along with an amount 

 of dye soln. not greater than twice the vol. of the object. 



6. Remove the end of the capillary from the drop and draw the 

 object in the dye soln. about 2 mm. in from the mouth. 



7. Dip the mouth of the capillary into water and draw in a 

 column about 1 mm. long. Remove from the moist chamber. 



8. Place a very small drop of mercury (which will fill 0.5-1 mm. 

 of the capillary) on a watch glass and carefully suck it halfway into 

 the mouth of the capillary and then push it all the way in with the 

 finger. The capillary should now look like the illustration in Figure 

 155. 



Mark 

 r5 mm. 



-2 



-1 



^0 



Fig. 155. Capillary for volume measurement, filled. 

 From Hotter (1945) 



9. With the capillary in a vertical position, measure the distance 

 between the menisci of the dye soln. with a micrometer miscroscope 

 (Fig. 151) to 0.01 mm. With a living amoeba, it is necessary to use a 

 filter to remove the heat from the source of illumination so that the 

 organism will not be disturbed. Movement of the amoeba to a menis- 

 cus may distort, or obstruct the view of the meniscus. 



10. Clean the capillary on the outside with wet filter paper, and 

 remove the mercury gently by combining it with a large drop of 

 mercury. 



11. Remove the water from the capillary with a tip of a strip of 

 hard moistened filter paper. 



