PRODUCTION OF MILK FOR CITY USE. 125 



descriptions, and in private dairies that were kept in an exceptional manner. 

 The average number of germs falling upon a surface the size of the usual 

 milking pail, in four minutes, the average time for milking one cow, was 

 17,680 in the average dairy; in a good dairy it was 8,080, and in a dairy 

 having a separate milking room and taking the precaution to wipe off the 

 sides of the animal and udder, 720 germs. In some of the very poor and 

 unclean places the total number ran up into the hundred thousands. The ad- 

 vantage coming from carefully cleaning and wiping the animal with a damp 

 cloth was so great that the precaution can not be omitted in any high class 

 dairy. It is not possible for all dairymen to have separate milking rooms, 

 roomy stables, or as much light and ventilation as science demands, but 

 they can all use this simple precaution. Another precaution of no small 

 meaning is that of emptying the first milk from each quarter on the floor. 

 The first milk drawn contains an immense number of germs as compared 

 with that drawn later. In our own experiments it was found that 

 in eleven successive milkings the first milk showed the following num- 

 ber of bacteria to be present per cubic centimeter: 122,400; 1,353,600; 

 15,400; 12,800; 32,000; 8,000; 14,400; 8,200; 5,000; 22,000 and 6,000. The 

 following is the average number found in the whole milk as taken from six 

 cows, the first milk not being saved; 10,600, 2,000, 2,000, 2,000, 2,200, 

 2,400 and 1,800, while the average for whole milk and the first milk not 

 drawn will be from 8,000 to 15,000 for the year. 



The milk should be removed from the stable as soon as drawn to avoid 

 contamination from the air and to prevent the absorption of odors. The 

 milk should not be strained in the stable, but this is preferable if done directly 

 into the large can than to allow it to stand. It is not an uncommon practice 

 to find the milkmen feed the cattle on sour slop immediately before milk- 

 ing, and without washing the hands go through the milking operation, and 

 as soon as through strain the milk into the ten or fifteen gallon route can 

 at a point within a few feet of the sour slop trough. Under such condi- 

 tions it is impossible to produce a milk that will keep, and makes the second 

 delivery a necessity. 



When milk is first drawn it has a temperature of about 100 degrees 

 Fahrenheit. It will lose a part of this heat and come to the same tempera- 

 ture as its surroundings in a greater or less length of time, depending 

 upon the bulk and the surface exposed to radiation. If left in the 

 large bulk of the eight or fifteen gallon can, the cooling process is slow, as 

 there is little surface from which to lose the animal heat, and nothing to 

 force the rapid circulation of all parts of the milk in the can to the surface. 

 In order to more effectively accomplish the cooling of milk, special apparatus 

 has been designed to reduce the milk to a very thin layer and to bring a 

 lower temperature into immediate proximity for the rapid absorption of 

 the heat. This is so effectively done that on even small coolers a pound of 

 milk will be spread over a surface of 8,000 square inches and from ten to 

 thirty degrees of heat removed in five seconds. An eight gallon can of 



