Bhioehy — Average Percentage of Fat in a Coirfs Milk. 55o 



day one, but occasionally it gives a less accurate one, and for that reason it is 

 not to be recommended. For instance, in diagram II (cow 128) the average of 

 the readings for June 25th, 26th, and 27th is further from the flattened curve 

 than that of June 26th and 27th ; that of July 7th, 8th, and 9th further than 

 that of July 7th and 8th. In diagram III (cow 97) the average of July 3rd, 

 4th, and 5th is less correct than that of July -3rd and 4th ; that of July 22nd, 

 23rd, and 24th is less correct than that of July 22nd and 23rd. 



The four-consecutive-day test having been suggested by the observations 

 made in 1915, the investigation was resumed in 1916. The work was begun 

 earlier, however, and continued till later in the year, so that periods of 

 extreme variation, if there were any, connected with the changes from house- 

 feeding to pasture in spring, and from pasture to house-feeding in autumn, 

 should be included. The investigation re-started on February 2nd and 

 ended on December 8th. An additional purpose in 1916 was to discover 

 the 2-elative variability of the different milk constituents ; to discover, for 

 example, whether the butter fat is relatively more variable than the 

 water. 1 Twelve normal cows giving a good average yield were selected, and 

 the following are relevant particulars : — 



The samples were taken and tested as before. In addition, a sample of 



1 Result of this part of experiment in another paper. 



4 s 2 



