556 



greater distance than 100 miles from London. As a rule, the evi- 

 dence showed that the cow-sheds from which the milk was derived 

 were ill-lit, overcrowded, badly ventilated and badly drained. Of 

 the milk-shops, 52 per cent, were found to have one or more 

 sanitary defects and 73 per cent, of the vendors failed to keep 

 the milk covered or protected from dust. The average number of 

 bacteria in unpreserved milk was found to be 2,370,000 per cubic 

 centimetre. Pus and dirt were present in numerous cases. In con- 

 sequence of the contaminated condition of the milk as commonly 

 supplied, various processes of heating milk have ben introduced 

 in order to destroy the numerous microorganisms and thus protect 

 infants and others from the effects of contamination. These methods 

 have been enthusiastically advocated by many writers, so that the 

 boiling or sterilisation of milk has almost come to be regarded 

 as a desirable practice, typical of sanitary advance and medical 

 progress. 



Whatever may be the excuse of expediency, the whole argument 

 is unsound and inconsistent with the principles of scientific proce- 

 dure. To supply an infant with contaminated milk is certainly far 

 from advisable but milk that has been contaminated remains con- 

 taminated whether boiled or unboiled. 



Moreover, boiling of the milk does not protect the infant. It 

 irretrievably injures the food of the infant, definitely destroying 

 elements essential to nutrition ; whilst the interference with the 

 natural processes of digestion is so great that the infant fed for 

 any considerable period on boiled milk suffers severely from mal- 

 nutrition directly arising from atrophy of the digestive glands. 



Among the poorer classes the boiling of milk plays an impor- 

 tant part in relation to the production of the most fatal disease 

 of infancy zymotic enteritis. This disease is chiefly caused by the 

 putrefactive decomposition of cooked milk. The changes that occur 

 can only be produced when the milk is cooked or its natural 

 characteristics are interfered with, raw milk being protected from 

 these poisonous changes by the action of the lactic organisms. 

 These organisms acting in raw milk, produce lactic acid and the 

 acidity thus engendered protects the milk from putrefactive changes 

 which can only occur in milk that is neutral or alkaline. For a 

 fuller discussion of the effects of the boiling of milk, vide the 

 writer's "Nutrition of the Infant", 3rd Ed. 1910. 



Recent developments in the milk trade have been distinctly 

 retrogressive. In the summer months it is becoming a common 



