BY fl. S. ttALCRO WARDLAW. 



839 



is due to the fact that the percentages of the constituents are not 

 given nearer than 0*5%, except in the case of the percentage of ash. 



Tlie mean vahies of the results in Table ii. are given below 

 (Table iii.). The maximal and minimal values of each quantity 



Table iii. 

 Maximal, minimal, and mean values of the composition and properties of 



cows' milk; and actual and relative ranges of variation of the results. 



are also given, so that its range of variation may be seen. To 

 make possible a comparison of the ranges of variation of the dif- 

 ferent quantities, the extreme range has been divided in each case 

 by the mean value of the series. The relative ranges of variation 

 obtained in this way may be compared together directly. 



Tlie relative variation of the density has been calculated by 

 dividing the range, not by the mean density, but by the difference 

 between the mean density and the density of water. The greatest 

 range of the values of density of milk in a series of observations 



