ELEVENTH ANNUAL YEAR BOOK— PART XI 611 



to which a small amount of washing soda has been added, and then scald- 

 ed. Never use a rubber tube between bottle and nipple, or a bottle with 

 corners. 



CONTAGIOUS DISEASE. 



If a case of typhoid fever, scarlet fever, diphtheria, or other contagious 

 disease breaks out in the family, do not return any bottles to the milk 

 man except with the knowledge of the attending physician and under 

 conditions prescribed by him. 



PASTEURIZATION. 



While efficient pasteurization destroys disease germs and affords a 

 safeguard against certain dangers, it should not be regarded as an insur- 

 ance against future contamination of milk, and the foregoing suggestions 

 should be observed in the case of pasteurized milk, as well as with ordi- 

 nary milk. Do not keep milk over twenty-four hours, even if it seems 

 to be sweet, as milk may become unfit for human food before it sours. 



THE HOME PASTEURIZATION OP MILK. 



BY L. A. ROGERS, BACTERIOLOGIST, DAIRY DIVISION, BUREAUN OF ANIMAL INDUSTRY. 



INTRODUCTION. 



Milk delivered in the cities in the summer months frequently contains 

 bacteria in such large numbers that it is not a safe food for children, es- 

 pecially for infants whose food consists entirely of milk. In many cities 

 a special milk can be secured, but this is sometimes difficult and always 

 involves additional expense. 



Under such circumstances it is advisable to pasteurize all milk con- 

 sumed by small children. The pasteurization should 'be done in such a 

 way that disease-producing bacteria as well as those likely to produce in- 

 testinal disturbances are destroyed without at the same time injuring the 

 flavor or the nutritive value of the milk. This may be accomplished in 

 the home by the use if a simple improvised outfit. 



METHOD OF PASTEURIZATION. 



Milk is most conveniently pasteurized in the bottles in which it is de- 

 livered. To do this use a small pail with a perforated false bottom. An 

 inverted pie tin with a few holes punched in it will answer this purpose. 

 This will raise the bottles from the bottom of the pail, thus allowing 

 a free circulation of water and preventing bumping of the bottles. Punch 

 a hole through the cap of one of the bottles and insert a thermometer. 

 The ordinary floating type of thermometer is likely to be inaccurate, and 

 if possible a good thermometer with the scale etched on the glass should 

 be used. Set the bottles of milk in the pail amd fill the pail with water 

 nearly to the level of the milk. Put the pail on the stove or over a gas 

 flame and heat it until the thermometer in the milk shows not less than 

 150° nor more than 155° F. The bottles should then be removed from 

 the water and allowed to stand from twenty to thirty minutes. The tern- 



