848 THE VARIABILITY OF COWS' MILK, i., 



The values correspondino- to the maximal ordinates of these 

 curves are the most probable values or modes, of the quantities 

 whose variations are represented. The figures for the modes of 

 the different quantities are given in Table vi. (p.851). 



The frequency curves of the values of the depression of the 

 freezing point, and of the density, are not shown in* the diagram, 

 as their ordinates are too high, in proportion to the ran^e of their 

 abscissae, to allow them to be conveniently represented on the 

 same scale as the other curves : all the results occur within a very 

 small range of the most probable values. 



The curves for the distribution of the other values fall obvi- 

 ously into three groups. 



In the first group are the curves for the values of the per- 

 centages of lactose, solids not fat, total solids, and ash, and the 

 value of the conductivity. The percentages of these values, 

 within 5% of the most probable values, range from 53%, in the 

 case of the concentration of lactose, to 41%, in the case of the 

 concentration of ash. 



In the second group are the curves for the values of the per- 

 centages of protein, and of fat. The percentages of results 

 within 5% of the modes are 19% and 20% respectively. 



The values of the weight of milk, and of the weight of fat, 

 form the third group. Between these two curves, lie those for 

 the distribution of the weights of the other constituents, as was 

 explained above. These two curves show that, in the case of 

 the weights of substances obtained at a milking, only 8*5 to 10% 

 of the results lie within a range of 5% of the mode. 



The concentrations of the substances in the first group are 

 thus at least twice as constant as those of the substances in the 

 second group. 



The concentrations, however, even of substances in the second 

 group, are at least twice as constant as the total weights pro- 

 duced, the curves for which are in the third group. 



The values of the percentages of fat, and of solids not fat, are 

 of great importance, as certain values of these quantities are 

 chosen as standards of the quality of milk. The distribution of 



