PRODUCTION OF MILK FOR CITY USE. 127 



change in the uncooled milk in six hours as in the cooled that was kept 

 cool in twenty-four or thirty hours. Tests upon acidulation fully agree 

 with the bacterial tests. 



Milk is delivered in four ways; by dipping from *arge cans, by drawing 

 from the bottom of the can, by carrying it in small cans sufficient for only 

 a few customers, and in glass jars of standard quantity, as quarts and pints. 

 Fully nine-tenths of the milk sold in cities is delivered by the first method. 

 Each method has its advantages and disadvantages. The delivery by 

 dipping from the large can is the most objectionable from a sanitary stand- 

 point. To empty a fifteen gallon can will necessitate the removal of the 

 lid on an average of 62 times. From our observations there will be four 

 half gallon customers, forty-six quart customers, and twelve pint custo- 

 mers. This means that in the time required to empty one can of milk 

 the top is removed and there is exposure for from thirty to forty minutes, 

 sufficient time for the entrance of from one hundred to one hundred and 

 fifty thousand germs on a dry summer day, and four hundred thousand on 

 a very dusty day. If the lid be made to fit into the top of the can instead 

 of fitting over it, it is an easy matter to allow as many more to be deposited 

 in removing and putting on the top. In the delivery of the product of 

 one day, some of the larger dairymen have the milk exposed to street con- 

 tamination for a period of fully two hours. The catching of 100,000 or 

 400,000 germs in fifteen gallons of milk is not such a large number when 

 we consider that bad milk may contain as many as 3,000,000 germs in 

 fifteen drops. It is the very rapid multiplication of these germs that causes 

 the unwholesome changes. 



In the delivery of milk by either the dipping process or by drawing 

 from the bottom, the infection does not end with the delivery to the customer. 

 The milk is nearly always received in an open vessel and carried into the 

 house, another period of exposure; sometimes not placed in a proper storage 

 place as soon as received, another exposure; and not infrequently received 

 in vessels used for the same purpose on the previous day, and having only 

 been rinsed they act as a starter for new growth, another exposure. The 

 dairyman may plead that he is not responsible for what happens to the 

 milk after it leaves his hands, but if the delivery can be made to avoid all 

 these injurious influences, it is so much to his credit. The delivery of 

 milk by drawing has an advantage over dipping just so far as it prevents 

 street infection. The small pail is used only to a very limited extent but 

 has the advantage of little exposure. The glass jar is decidedly preferable 

 to any of these methods. It obviates all exposure on the street and in 

 delivery, the milk is kept in its package until ready for use, and only such 

 forms are present as gained entrance at the time of bottling, and the num- 

 ber depends upon their multiplication. The most serious objection that 

 can be urged against the use of the bottle is that it may be used in the home 

 where there may be sickness on one day and in another family on the suc- 

 ceeding day. This demands that the bottles be thoroughly cleaned and 



