94 "COEFFICIENT OF DIFFUSION OF CELLS" 



(7 units of heat) for 10 minutes (1 unit of time). The 

 index of diffusion of the jelly is this: 



/ar=(4* + 2o) (3c + n), 



where s = unit of stain, a = unit of alkali, c = unit of 

 sodium citrate, and n = unit of sodium chloride. 



At the expiry of the ten minutes the specimen is 

 examined, when it will be seen that the lymphocytes 

 are quite unstained; but the granules of the polynu- 

 clear leucocytes are just beginning to colour red. To 

 find the cf of these cells, however, it is stipulated that 

 their nuclei should just stain. The specimen is there- 

 fore replaced into the incubator for a further ten 

 minutes. Now it will be found that the nuclei of 

 the eosinophile leucocytes are just staining. Hence, 

 although this jelly has not yet given us the coefficient 

 of diffusion of the neutrophile leucocyte, it has de- 

 termined that of the eosinophile cell, which may be 

 set down as follows: 



Eosinophile leucocytes 



where h = unit of heat and / = unit of time. 



In order to stain the nuclei of the neutrophile cells, 

 we could place the same specimen for another ten 

 minutes in the incubator; but it is not a very safe 

 thing to do, for the cells by this time may be dead. 

 It is better to make a fresh film from another jelly 

 which contains more units of a factor which increases 

 diffusion. We may add more stain or more alkali. 

 Let us try another unit of each, thus: To a fresh tube 



