9 



LETHAL DOSE 

 100 



NORMAL DOS 



00 



dicular on the right the degree of injury is very readily noticed and 

 starvation or symptoms of starvation are set up. Thus if you follow 

 the perpendicular on the right downward to the point 80 the diver- 

 gence of the corresponding point of the curve is already measurable. 

 As you descend to the magnitude of the measurement increases. 

 It requires^ but very little further illustration to show how easily 

 the effect of diminishing the normal dose of a food can be measured 

 immediately after the curve begins to vary appreciably from the 

 perpendicular on the right. 



Let us now consider the perpendicular on the left, which is marked 

 at the top under the term " Lethal dose/' namely, a quantity of the 

 added preservative sufficient to destroy life. The normal dose of 

 such an added 

 chemical preserva- 

 tive is and is 

 shown at the base 

 line to the right, 

 marked " Normal 

 dose." If you add 

 a very minute 

 quantity of a chem- 

 ical preservative, 

 the curve repre- 

 senting it varies so 

 slightly from the 

 horizontal base as 

 to be impossible 

 of measurement by 

 ordinary means. If 

 we follow along to 

 the number 75 on 

 the horizontal base" 

 we see the devia- 

 tion of the curve is sufficiently great to measure. At 50 it is still 

 greater, at 25 still greater, while at the left of the basic line it is a 

 maximum extending from to 100, or the lethal dose. It is easy to 

 show by mathematical data that no matter how small the quantity 

 of an injurious substance or preservative it will still produce an 

 injurious effect which may be infinitely small if the dose be infinitely 

 small. It follows, then, as a mathematical demonstration that any 

 quantity of an injurious substance added to a food product must of 

 necessity be injurious, provided it is in the nature of a drug and the 

 body is in a perfectly healthy, normal condition. 



Hence the argument which has been so persistently urged in favor 

 of a chemical preservative, that if in small quantities it is harmless, 

 is shown to be wholly untenable. While there is no necessity for 



LETHAL DOSE 



.50 





 75 NORMAL DOSE 



FIG. 1. Graphic chart representing the comparative influences of 

 foods and preservatives. 



