ABNORMAL MILKS. 57 



oped organisms will be killed. This process is repeat- 

 ed several times and finally complete sterilization is ef- 

 fected. 



For the practical purpose of rendering milk safe as 

 an article of food, it is not necessary to make repeated 

 heatings. Numerous investigations are reported on 

 this point, one of the most recent being a paper by 

 Dr. R. G. Freeman (Med. Rec. June 10,1893). A 

 temperature of i6;F (75C) continued for fifteen min- 

 utes, followed by rapid cooling by immersing the con- 

 taining vessel in water, will kill the adult forms of most 

 microbes, and milk so treated will remain unaltered for 

 one or two days and will not have suffered any ap- 

 preciable loss of digestibility, even for infants. 



When it is considered that milk is almost the only 

 form of animal food that is eaten in the uncooked 

 condition, by civilized communities, the importance of 

 the facts above noted will be apparent. Some inter- 

 esting data as to the association of consumption, diph- 

 theria, and similar diseases, with the maintenance of 

 dairies have been collected, but the discussion of this 

 feature of the question would be out of place here. 

 Enough is known to show that raw milk is not a safe 

 article of food, unless collected with such precautions 

 as will prevent the introduction of infectious matter. 



Artificial coloring matters do not involve any 

 serious danger to health, except Martius' yellow, 

 (dinitroalpnanaphthol) which is poisonous. The obvi- 

 ous objection to their use is that they enable milk of 

 inferior quality to be substituted for rich milk. It is 



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