BOILED MILK OF THE SAME SPECIES 



167 



to which, in many cases, one of these salts had been added. Full 

 data are given, and the results tabulated. The table which is 

 given below shows not only the weights of the calves, but also the 

 solids contained in the milk taken, and the amount of milk taken 

 by the calves of each series, in order to put on I kilo, of body- 

 weight. 



Some of the experiments were carried out over a period of 

 ten weeks and others over a period of fifteen weeks. 



Hittcher's table cannot be summarised ; it must be studied for 

 itself in detail. He has arranged it so that there is an ascending 

 series of figures under the heading of the amount of milk required 

 to produce one kilogram of increase of body-weight. 



If this be taken as the main criterion of the nutritive value of 

 any food-stuff, then the striking fact appears that the addition of 

 salts is of much greater importance than the question as to whether the 

 milk is given raw or boiled. It is difficult to assess the precise value 

 of the figures in the other columns in comparing the results of each 



Table of Results obtained by Hittcher 



series with one another. If the amount of milk required to pro- 

 duce one kilogram increase in body-weight in Groups I and 2 

 is considered, it is then seen that less boiled milk is required 

 than raw milk ; that is, the boiled milk would appear to be more 

 nutritious. 



Owing, however, to the paucity of data dealing with the amount 

 of milk required to give an increase of one kilogram of body-weight, 

 it has been necessary to take the gain in absolute weight, as the 

 criterion of nutritive value. Upon this basis, if the Groups I 

 and 2, and 7 and 3, be examined, then there appears to be some 



