Butter Making 
5 
trolled by the butter maker no matter whether the output is a thousand 
pounds a day or six pounds a week. Clean milk can be obtained only 
by the most scrupulous care on the part of those who are entrusted 
with the handling, and the proper ripening of the cream is best 
accomplished by the use of what are known as commercial starters, 
which will be discussed fully later on. 
To the majority of people who use milk or cream in one form or 
another, clean milk signifies milk free from visible dirt, such as cow 
hair, hay, straw, etc. As a matter of fact, such forms of dirt are 
seldom met with in the milk as delivered to the consumer, and of 
themselves are practically harmless except to the esthetic taste. The 
milkman has learned to strain his milk and rid it of such debris. It 
is the filth that we can not see with the unaided eye that does the harm 
and makes the consumption of dirty milk dangerous. Every particle 
of dust, every hair, every bit of straw is covered with myriads of 
bacteria, and when these foreign substances find their way into the 
milk, the germs are washed off and immediately begin to grow and 
multiply in the milk. When we know that a single cow hair may 
harbor from 4,000 to 10,000 germs which can multiply once every 
half hour, are we not justified in labeling milk which contains such 
hairs as unfit for use? 
When every precaution is taken against contamination, it is pos¬ 
sible to obtain milk directly from the cow which contains as few as 
200 to 300 germs per cubic centimeter (one-fourth of a teaspoonful) ; 
with somewhat less care the numbers will increase to 5,000; when 
carelessly drawn and handled, it frequently contains in the beginning 
from 25,000 to 100,000. 
Many of our large cities have placed a limit to the number of 
bacteria which the city milk supply may contain and yet be offered for 
sale. The city of Boston (1) has set this number at 500,000, Rochester, 
N. Y., 100,000, and Milwaukee 250,000. In New York City, Park 
(2) found that during the coldest weather, the milk sold in the shops 
averaged over 300,000 bacteria per cubic centimeter; during cool 
weather, about 1,000,000 ana during the hot weather, about 5,000,000. 
In Chicago, Jordan and Heineman (3) found in market milk collected 
during April, May and June, numbers ranging from 10,000 to 74,000,- 
000. Sedgwick and Batchelder (4) have examined samples of milk 
from groceries in Boston which contained over 4.500,000. Stevens 
( 1 ) . Article 51 , Sect. 1 . Regulations for the Sale and Care of Milk, Bos¬ 
ton Board of Health. 
( 2 ) Park: Jour. Hyg., 1 , 1901 , I, p. 391- 
( 3 ) Jordon and Heinemann: Rept. of Civil Federation of Chicago, 1904 . 
( 4 ) Sedgewick and Batchelder: Bost. Med. ,J our -> 1892 , 126 ,p. 25 . 
