BY H. S. HALCRO WARDLAW. 



615 



Table i. 

 DtTmity of fat remoi'ed from cows' milk hy spinning. 



The determinations of density were made as described in a 

 previous paper (Wardlaw, loc. cit.), water at 25°C. being taken 

 as standard. The results have an error of al^out 1 in 10,000. 



If the two errors are maximal and fall in opposite directions, 

 the calculated density of the fat will have a possible error of 

 about 2% The actual values obtained, as shown above, have 

 an extreme range of rather less than this, from 0-921 to 0-938, 

 and the variation from the mean is less than 1%. 



The above results show that the densities of the fat removed 

 by spinning from the samples of milk examined varied between 

 0-921 and 0-938; 0-93 has been taken as the mean value in the 

 subsequent calculations. This value agrees well with that ob- 

 tained by previous investigators (Fleischmann, 1885). 



The following Table shows the percentages of fat and electrical 

 conductivities (K) of various mixtures in whole and spun milk in 

 the case of different samples, and the ratios of the decrements of 

 conductivity to the corresponding increments of fat-content. 



If the decrement of conductivity is directly proportional to 

 the increment of fat, these ratios will be constant for each 

 sample of milk. 



