Another fact worthy of consideration is that inasmuch as milk is 

 the most prone of all ordinary foods to deterioration and requires the 

 most careful treatment the temptation to use such an efficient pre- 

 servative as formaldehyde is proportionately greater, especially dur- 

 ing the summer months. The arguments which have been advanced 

 in favor of other preservatives in small quantities should theoretic- 

 ally carry more weight in the case of milk than of other common 

 foods, and if these arguments are valid in any case they would be 

 especially so when applied to dairy products. It is generally admitted 

 that there is no known preservative so effective, so readily employed, 

 and in some respects so likely to escape detection as minute quanti- 

 ties of formaldehyde, and therefore all the conditions which relate 

 to its use deserve the greater care and consideration. It should not 

 be forgotten, however, that a supposititious commercial necessity can 

 not be cited as an excuse for the addition to foods of substances 

 which are injurious. 



In this connection it seems not out of place to call attention to the 

 fact that apart from the injurious effects of formaldehyde itself its 

 use as a preservative would be especially inadvisable in milk or cream, 

 because its addition in dilute solution prevents the growth of acid- 

 forming bacteria, but has no effect in retarding the action of many 

 harmful organisms; in other words, the milk is prevented from becom- 

 ing sour, and thus indicating its age, and the danger signal is thus 

 removed while the other -organisms which are capable of producing 

 disease continue to multiply in the milk with practically the same 

 degree of rapidity as if the formaldehyde were not present. 



Attention is again called to the proper and legitimate signification 

 of the term " injurious to health," when used in this connection. 

 This phrase does not signify that a food which has an injurious sub- 

 stance added to it must in every instance produce notably injurious 

 effects upon the consumer immediately. The question can only 

 be logically and fairly studied by considering the continued or cumu- 

 lative effects, nor are these necessarily of such a character as to result 

 in objective symptoms. Insidious effects which are produced on 

 the cells of the organs or on their histological structure are no less 

 important; in fact, they are more important. These are the injuries 

 which at first escape detection and may go to irremediable lengths 

 before any outward symptoms of their existence are manifested. 



All of these points have been kept in view iri the consideration of 

 this question, but none of them has had any influence on the obser- 

 vation and recording of the data. As in all other cases, this part of 

 the work has been conducted absolutely without reference to any pre- 

 conceived theory. The sole endeavor has been to control the quan- 



[Cir. 42] 



