328 THE MILK SITUATION IN THE DISTRICT OF COLUMBIA. 



The bacteria or germs which cause the various infectious diseases, such as 

 typhoid fever, scarlet fever, diphtheria, consumption, etc., readily live and 

 multiply in milk, and outbreaks of these diseases have been frequently traced 

 to contamination of milk by careless farmers or milkmen, who have infected 

 the milk with disease germs from their hands, from improperly sterilized bottles 

 or cans, from polluted water, or from other sources, either while themselves 

 sick or recovering from some one of these diseases, or while nursing others who 

 were suffering from them. Many thousands of cases of illness and death have 

 thus been produced from such causes. This is, of course, entirely unnecessary, 

 and can easily be prevented. It is most important, therefore, for all persons 

 who handle milk to know from what portion of the body these minute germs 

 are given off, so that they may adopt the necessary precautions to prevent 

 infection of the milk. 



The germs which cause scarlet fever are thrown off in the discharges from 

 the nose and throat and in the scaling from the skin. Those which cause 

 typhoid fever are found in the urine and feces, and thus often reach the spring 

 or well water with drainage which has leaked into it. Those which cause 

 consumption and diphtheria are contained in the expectoration. The germs 

 from cows which are diseased, especially when affected with consumption and 

 tuberculosis of the udder, may also infect the milk and produce sickness in 

 those who drink it. The bacteria which cause milk to sour and ferment and 

 so become unwholesome are derived from manure and dirt which drop into 

 the milk pail from the cow's belly or udder or tail, or from the dust of the 

 barn, or from the dirt off the milker's hands, or they are contained in the pails 

 and dirty strainers and cans, which have not been thoroughly cleaned and 

 sterilized after having been previously used for milk. 



The pails into which the milk is drawn should not be of the large, open-top 

 variety, but should be covered with as small an opening at the top as can be 

 used in milking. If everyone would use covered milk pails much of the dust 

 and dirt which falls into the milk during the process of milking would be 

 prevented and fewer bacteria would be found in the milk. 



When milk is collected under cleanly conditions, the number of bacteria 

 which fall into it is much less than when the conditions are dirty. 



Milk affords one of the best foods for the growth of bacteria. When fresh, 

 however, it contains substances which retard somewhat the development of 

 bacteria for a few hours, if they are not too numerous, but we depend upon 

 low temperatures to further limit changes in it. Just as large forms of plant 

 life can not grow in cold weather, so also these minute germ plants are pre- 

 vente'd from multiplication by cold. For this reason all milk should be rapidly 

 cooled and kept cold until used. 



Bacteria found in milk generally multiply most rapidly at blood heat, and 

 cease to multiply at all at the freezing temperature. Any reduction of the 

 temperature below 95 F. limits the rapidity of growth, but it is not until the 

 temperature is reduced to 45 or 50 F. that the growth is nearly arrested. At 

 32 F. milk remains unchanged for an indefinite period. In fresh milk, 

 properly collected and quickly cooled at 50 F. and kept at this temperature, 

 during the first 24 hours there is no increase in the number of bacteria ; after 

 24 hours the peculiar properties of fresh milk to resist the growth of bacteria 

 become exhausted, and the bacteria also become gradually accustomed to the 

 cold, so that even at this temperature they may rapidly increase and in a few 

 days cause the milk to become sour. 



It is impossible to obtain cow's milk under the ordinary conditions which 

 exist in most milk barns without allowing some bacteria (which always abound 

 in the dirt and dust of the barn and on the cattle) to drop into it, but the num- 

 ber may be limited. It is wholly unnecessary and inexcusable to permit the 

 germs of the diseases of human beings or cattle to contaminate the milk. The 

 fewer bacteria found in milk the more wholesome it is, and when the number 

 becomes very large, the milk becomes not only unwholesome but dangerous, 

 and the use of such milk is the commonest cause of the diarrheal diseases of 

 children, particularly prevalent in summer. The importance of this may be 

 appreciated when it is known that 1,188 deaths occurred from the diarrheal 

 diseases in the city of Providence among children under the age of 2 years 

 during the last five years (1902 to 1906, inclusive). 



Under present conditions considerable time must elapse before the milk 

 reaches the consumer, and before it is used, and if it is not very carefully 

 handled and kept cold the number of germs contained in it when used becomes 

 very large and sometimes almost incredible. There may be at the end of a 



