WALLACE O. FENN 



455 



In Experiment 1 , K and logarithm A were determined by the method 

 of least squares; in Experiment 2, they were measured graphically. 

 In the latter instance K was nearly ten times as high as in the former. 

 This may have been due to a difference in the cells or in the serum. 

 The quartz suspensions used were identical. 



/r-^ 



Fig. 4. Photograph of quartz suspension 4.6 ^ in diameter, to show uniformity 

 In size of particles. 



Log A-x 



Hour5 



Fig. 5. Experiment 1. Ordinates represent logarithms of the number of par- 

 ticles not taken up by leucocytes plotted against time as abscissae. K is equal to 

 the slope of the graph. Quartz particles of three different sizes are compared, 

 designated as in Fig. 6. Experimental ratios, 1:0.42:0.64; theoretical ratios, 

 1 : 0.41 : 0.51. A' determined in this experiment by method of least squares. See 

 Table III. 



