THE SUPPLY OF PURE MILK 299 



and essential if that article of food is to serve as healthy 

 diet. In this case (as so many others) it is the attempt 

 of greedy traders to make money by giving to a worth- 

 less spoilt article the appearance of the regular and 

 valuable article, which has led to disease and disaster. 

 It becomes more and more obvious that the selection of 

 articles of food and the whole question of what is a 

 healthy diet, are not such simple things as is often 

 supposed. Here, as in everything we do, we must 

 either keep to the long-established habits sanctioned by- 

 Nature, or we must have full and detailed knowledge to 

 guide us in new ways, so that we shall not recklessly 

 blunder by ignorance into disaster and death. The 

 " feeding " of man and of his herds requires new and 

 continued investigation. Old convictions and traditions 

 in these matters must not be lightly thrust aside by the 

 possessor of that little knowledge which is a dangerous 

 thing. Meanwhile, for the civilized man the advice 

 of Pasteur's pupil and successor, the late Professor 

 Duclaux, is noteworthy : " Do not eat much, but eat 

 many things ; there is safety in variety, danger in 

 uniformity." 



When we reflect on the importance of these small 

 quantities of easily destroyed constituents in natural 

 foods, we begin to appreciate the difficulty of securing a 

 pure milk-supply which shall be at the same time a 

 nourishing and a healthy one. The sterilizing of milk 

 by heat before it is sold as an article of diet seems to be 

 desirable in order to destroy the bovine tubercle-bacillus 

 which may be there and the other injurious microbes due 

 to the dirty conditions in which the cow is kept and the 

 milkers keep themselves. The heating of the milk for 

 some twenty minutes to a temperature below that of 

 boiling water seems to be the best plan. For infants, 



