330 



MILK 



to be shipped for a considerable distance by railway. Special 

 refrigerator cars are provided by some railway companies for 

 transportation of milk, and in these milk is preserved in good 

 condition for many hours. Frequently, however, milk cars are 

 not suitably constructed, and the bacterial content increases mark- 

 edly during transportation. This is especially true in summer. 



James 0. Jordan, in reporting an investigation of the dis- 

 tribution of ice for keeping milk cool, says that of 48 cases, 10 had 

 no ice; 26 were inadequately iced; 3 had the ice improperly dis- 

 tributed, and only 9 were good. The author states, furthermore, 

 that health authorities do not or are not permitted to inspect rail- 

 way milk cars, and that proper control is therefore lacking. 



Fig. 165. — Milk-cans at the railway station. (Fraser, Bull. No. 92, Univ. of 

 lU. Agric. Exp. Sta.) . 



The time schedule of milk trains leaves much to be desired, as 

 it prolongs the period that milk has to travel and, consequently, 

 there is the chance of increased bacterial growth. When milk is 

 shipped in bottles they are usually packed in boxes and the boxes 

 filled with chipped ice. The temperature is kept low for twenty- 

 four to thirty-six hours by this means. Ordinances have been 

 enacted that provide for the dehvery of milk at low temperature, 

 the highest permissible limit being usually 60° F. However, even 

 at this temperature there is considerable germ growth, and the 

 requirements should be lowered to 50° F. At this temperature 

 growth is slow for a few days at least. Near the freezing-point 

 there is usually an actual reduction of bacteria for a Hmited period 

 which is long enough to keep the germ content low up to a reason- 

 able time of consumption. But since some bacteria possess con- 

 siderable tolerance toward low temperature, a decided increase 



