AmAJpOrii;i906arm'}        Use  of  Preservatives  in  Foods.  165 
grains  of  benzoic  acid  daily,  instead  of  one  grain,  by  what  right  of 
authority  should  he  say  that  0*5  per  cent,  of  boric  acid  in  foods  is 
harmless  and  a  greater  amount  harmful?  Such  a  discrimination  is 
neither  logical,  scientific  nor  hygienic.  Yet  it  is  upon  such  testi- 
mony it  is  asked  that  the  authority  of  the  Secretary  of  Agricul- 
ture to  consult  such  experts  as  he  deems  advisable  in  respect  of 
wholesomeness  should  be  denied  by  an  amendment  to  the  food  bill, 
and  this  matter  be  determined  by  a  board  of  five  experts  appointed 
by  the  Secretary,  one  of  whom  shall  be  a  physiological  chemist,  one 
a  pharmacologist,  one  a  bacteriologist,  one  a  pathologist  and  one  a 
toxicologist. 
I  cannot  better  answer  the  arguments  which  would  indicate  that 
a  small  quantity  of  a  chemical  substance  may  be  used  without  pro- 
ducing harm  than  to  refer  to  the  chart  (p.  166),  which  I  presented  to 
the  Interstate  and  Foreign  Commerce  Committee.  Simply  because 
an  effect  is  so  small  that  it  cannot  be  measured  is  no  reason  for  deny- 
ing its  existence.  Any  given  measurable  quantity  is  made  up  of  an 
infinite  number  of  small  quantities  of  the  same  kind.  I  believe  that 
every  expert  will  admit  that  there  are  certain  quantities  of  chemical 
preservatives  which  are  injurious,  that  is,  which  produce  an  effect 
which  can  be  measured.  They  must  also  admit  that  the  effect  is 
the  sum  of  an  infinite  number  of  small  effects  and  that  each  of  these 
infinitely  small  effects  is  produced  by  an  infinitely  small  quantity  of 
the  preservative  in  question.  We  may,  therefore,  present  this 
graphically  as  I  do  in  this  chart,  in  which  I  have  compared  the 
normal  effects  of  foods  and  chemical  preservatives  by  the  construc- 
tion of  two  curves  intersecting  each  other  above  the  median  point 
of  the  base  line. 
We  assume  in  the  discussion  of  this  chart  that  in  a  state  of  health 
no  one  needs  a  dose  of  any  chemical  preservative  and,  therefore,  the 
normal  dose  of  a  chemical  preservative  is  zero,  as  represented  on  the 
chart.  We  may  represent  the  lethal  dose  of  a  chemical  preservative 
by  100  and  may  assume  three  points  to  be  measured  on  a  curve,  by 
means  of  which  it  may  be  constructed  or  plotted.  In  the  same  way 
we  may  construct  a  curve  showing  the  effect  of  foods  in  a  state  of 
health,  in  which  the  normal  dose  is  that  which  keeps  the  body  in  a 
state  of  equilibrium  and  may  be  represented  by  100.  The  lethal 
dose  of  food  is,  of  course,  zero.  Now  it  is  evident  that  we  cannot 
measure  the  infinitely  small  effect  of  an  infinitely  small  dose  of  a 
