510 THE PASTEURIZATION OF MILK 



Under such circumstances one cannot tell by the appearance or 

 taste of the milk that it is damaged and that it contains the product 

 of decompositon of the albumin, or possibly even toxic substances. 

 On the whole there is no way, at the present time, of determining 

 whether or not pasteurized milk was damaged before it was heated, 

 while with respect to raw milk the keeping quality and bacterial 

 content furnish sufficient evidence regarding its true condition. The 

 bacteria surviving pasteurization are, for the most part, the quick- 

 growing bacteria of putrefaction which are inhibited in raw milk 

 by the lactic-acid bacteria, but in pasteurized milk they multiply very 

 fast and undoubtedly they are capable of generating poisonous 

 substances. It has been suggested, therefore, that a pure culture of 

 lactic-acid bacteria be added to milk after pasteurization in order to 

 check the bacteria of putrefaction. In purchasing pasteurized milk 

 one cannot tell if it be fresh or old and cannot determine from its 

 appearance whether putrefaction has begun or if only a few bacteria 

 are present. If we compare the advantages and disadvantages it will 

 be found that there is serious doubt as to whether it is advisable to 

 endeavor to obtain general pasteurizaton of market milk, as has been 

 suggested in Germany." 



While there can be no objection to the home pasteurization of 

 milk, in order to destroy pathogenic bacteria which might be present, 

 and to impart to milk better keeping qualities, compulsory pasteur- 

 ization of most of the market milk supply, decreed by city ordinances 

 has appeared very objectionable to the author, and he has had occasion 

 to express his views on such measures as they have been enacted in 

 the city of Chicago. 



Summary of Objections. A summary of these objections against 

 the wholesale pasteurization of the milk supply of a big city is con- 

 tained in the following paragraphs: 



1. It is known that the exclusive feeding of sterilized or pasteur- 

 ized milk to infants and children has a tendency to produce rickets 

 and scurvy. This is due to the fact that any effort at pasteurization 

 which will destroy a high percentage of bacteria will also destroy 

 several very important soluble ferments or enzymes contained in 

 milk. The latter are absolutely necessary for the proper nutrition 

 of the infant body, which does not yet furnish these ferments, as is 

 done in later life. The production of rickets has been frequently 

 observed not only in man but as well in some of the lower animals, 

 particularly in small, fancy, high-bred dogs, which often have to be 

 brought up on pasteurized milk because the mother's milk is secreted 

 in insufficient quantity and the puppies do not well tolerate raw 

 cow's milk. On the other hand it is claimed that the feeding of 

 pasteurized cow's milk to calves has not been followed by any evil 

 consequences to the cattle stock of Denmark, where this method of 

 feeding has been practised quite extensively for a number of years. 

 However, observations made on calves fed with pasteurized cow's 



