THE USE OF SMALL QUANTITIES OF THE PRESERVATIVE. 



The arguments which have been advanced in excuse of the use of 

 preservatives, when used in minute quantities, have perhaps been more 

 vigorously urged for salicylic acid than for almost &ny other sub- 

 stance. Since the publication of Part I of this bulletin this argument 

 has been urged with such vigor and such ingenuity that a further 

 reference may not be out of place in these general conclusions. The 

 principle which is laid down is that a substance which is injurious to 

 health when added to foods, if not a natural constituent thereof, or if 

 not added for condimental purposes, does not lose its power of injury 

 to health because it is diluted or given in small quantities. 'The only 



LETHAL DOS 

 100 



NORMAL DOSL 

 100 



LETHAL DOSE " 50 75 NORMAL DOSE 



FIG. 3. Graphic chart, representing the comparative influences of foods and preservatives. 



change which is made is to mask the injurious effects produced, to 

 make them more difficult of ascertainment and impossible of measure- 

 ment. This subject was fully discussed in the hearings before the 

 House Committee on Interstate and Foreign Commerce in February, 

 1906. 



The fallacy of the argument that small quantities of an injurious 

 substance are not injurious may perhaps be best represented graphically. 

 The chart which accompanies this discussion shows theoretically the 

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