268 ANNUAL REPORT OF THE Oil. Doc. 



There are also on the market domestic pasteurizers intended for 

 pasteurizing milk lor infants. These usually consist of a set of 

 bottles suspended in a vessel of water. An ordinary range or a small 

 oil stove may be used for heating the water. A thermometer in one 

 of the milk bottles indicates when the desired temperature has been 

 reached. 



While pasteurizing milk destroys the disease germs, authorities 

 are not agreed upon the value of pasteurized milk for infants and 

 invalids. Undoubtedly the albumen undergoes a change even at a 

 temperature as low as 150 degrees F. This change renders it less 

 digestible. It is a question whether the danger from the organism 

 in ordinary milk is greater than that from the indigestibility of the 

 pasteurized product. Undoubtedly, if milk is known to have been 

 produced and handled under sanitary conditions, the raw product is 

 to be preferred. It is almost impossible to pasteurize milk without 

 imparting to it a certain flavor which is more or less noticeable. 

 While this flavor is not relished by most people at first, others never 

 detect it at all; some persons even acquire a taste for it, so that they 

 prefer pasteurized to raw milk. 



Pasteurization of milk for city supply is on an increase, especially 

 in the West where the methods of handling and caring for milk are 

 more crude than those of the large, up-to-date Eastern model farms. 

 Pasteurized milk under similar conditions contains fewer germs than 

 unpasteurized milk, even if the raw milk is handled under the most 

 sanitary conditions. Pasteurization, however, should never be al- 

 lowed to take the place of sanitary handling. The numbers of germs 

 in milk is not an absolute index of its safeness. A very small num- 

 ber of pathogenic germs would be more harmful than a million lac- 

 tic acid producing germs. Lactic acid seems to retard the develop- 

 ment of putrefactive germs, and its presence in the intestines is 

 often beneficial rather than injurious. 



STANDARDIZATION OF MILK. 



A partial modification of milk is made by some who own up-to- 

 date dairy farms^ where hygienic milk is produced. This modifica- 

 tion extends only to the changing of the fat content; for instance, 

 orders may be filled calling for milk with 2 per cent, fat, 4 per cent, 

 fat, 6 per cent, fat, or milk containing any amount of fat. If the per- 

 centage of fat content exceeds a certain standard (about 5 per cent.), 

 then the price for one cent a quart for each per cent, of fat it con- 

 tains; for instance, if cream tested 35 per cent, fat, then it would sell 

 for 35 cents per quart, and if it contained 50 per cent, fat, then it 

 would sell for 50 cents per quart. 



This modification of the fat content of milk is accomplished by 

 ikimming the whole milk. The cream obtained is tested for fat by 



