CLASSES OF MILK 371 



soon produce sufficient acid to check, if not kill, the putrefiers which 

 give rise to ptomaines. 



Milk undoubtedly owes its beneficial action to its lactose which 

 is slowly absorbed and hence regulates the biochemical changes 

 which take place in the lumen of the intestines. Hull and Rettger 

 have conclusively demonstrated that a high lactose diet markedly 

 influences the intestinal flora of man. 



Hence, nothing should be done or said to decrease the consump- 

 tion of milk, but much should be done to see that the milk consumed 

 is pure, clean, and free from disease-producing bacteria. For although 

 milk is one of the cheapest and best of foods it is responsible for 

 more sickness and deaths than perhaps all other foods combined. 



Classes of Milk. Milk is often roughly divided into three classes, 

 depending upon the care exercised in its production and handling- 

 certified milk, inspected, or guaranteed milk, and common milk. 



Certified milk has no unusual properties other than those of 

 exceptional cleanliness and purity. It is milk which has been pro- 

 duced according to the regulations and under the supervision of a 

 medical milk commission. The cows from which the milk is pro- 

 duced are tuberculin-tested. The stable and cows are kept extremely 

 clean and no dust is allowed in the stable at the time of milking. 

 Small-top sterilized pails are used. The cows are carefully groomed 

 long enough before milking to let the dust settle. The cow's udder 

 and flanks are washed just before the milking. The milker wears a 

 white suit and washes his hands before milking each cow. The milk 

 is cooled either before or after bottling. The caps are so constructed 

 that they completely cover the top of the bottle, and many dairies 

 use a double cap. The caps are sterilized before use and the milk 

 is kept cool during transit. The number of bacteria should not 

 exceed 10,000 per c.c. of milk. Moak gives the average count of 

 321 samples of certified milk delivered in Brooklyn during 1910 as 

 4095 bacteria per c.c. 



Such milk is as near pure as it is possible to produce it on a com- 

 mercial scale, and although it is required that it be delivered to the 

 consumer within thirty hours after production, yet it will keep for a 

 great length of time. At the Paris Exposition in 1900 certified milk 

 from the United States, to the astonishment of the judges, was 

 placed on exhibition in perfectly sweet condition after a journey of 

 fourteen to eighteen days, or 3000 to 4000 miles, in midsummer. 



It is probable that in none of our large cities does the production 

 of certified milk exceed 1 per cent, of the total supply. This is due 

 to the greater price which must be charged for such milk, and the 

 tendency at the present tim^s to produce a high grade of milk 

 under less ideal condition sm Ik can be sold at a more moderate 



price. 

 This is being met in the^Wted, inspected or guaranteed milk 



