1 64  Use  of  Preservatives  in  Foods.  {AmAprU'i^rm' 
the  exclusion  of  every  kind  of  preservative  from  milk,  as  I  have 
already  said,  is  certainly  a  confession  that  he  believes  these  things 
are  injurious.  But  it  may  be  said  in  extenuation  of  this  that  milk 
is  peculiarly  the  food  of  the  infant.  I  do  not  desire  to  contradict 
that  statement,  which  is  doubtless  true.  But  in  what  is  the  diges- 
tion of  the  infant  different  from  the  digestion  of  the  adult  ?  In  no 
respect  whatever  except  that  of  a  mechanical  difference.  The  infant 
is  incapable  of  mastication.  Therefore  he  cannot  use  solid  food. 
Milk  is  a  perfectly  balanced  food.  It  contains  all  the  elements 
necessary  to  the  sustenance  of  the  body  and  in  proportions  best 
suited  for  nutrition. 
"  In  case  of  illness  among  adults  where  digestion  is  disturbed, 
milk  is  a  most  reliable  and  common  diet,  since  it  is  easiest  digested. 
Therefore  if  preservatives  interfere  with  digestion  they  would  have 
a  less  harmful  effect  than  on  any  other  food  product,  because  milk 
of  itself  is  easiest  of  digestion. 
"  The  process  of  metabolism  in  the  infant  is  exactly  that  in  the 
adult.  Metabolism  consists  in  the  change  of  foods,  first,  into  sol- 
uble forms  and  then  the  change  in  the  character  of  these  soluble 
forms  by  absorption  into  the  system,  and  by  utilization  in  building 
of  tissues,  and  finally  by  degradation  into  excretion  products.  With 
the  exception  of  the  mechanical  division  of  foods  by  mastication 
these  two  processes  are  absolutely  identical  in  the  infant  and  the 
adult. 
"  It  follows,  therefore,  as  a  reliable  and  logical  conclusion,  that 
any  added  substance  which  renders  milk  deleterious  would  have  the 
same  effect  on  any  other  food  in  which  it  might  be  used." 
The  particular  testimony  of  Dr.  Vaughan  to  which  I  refer  is  found 
on  page  65  of  the  hearings  before  the  Interstate  and  Foreign  Com- 
merce Committee : — 
"  I  am  sure  that  benzoic  acid  in  the  quantities  in  which  it  is  used 
in  tomato  catsup,  sweet  pickles,  etc.,  one  part  to  1200  or  2000, 
does  not  do  any  harm.  I  should  be  opposed  to  the  use  of  formal- 
dehyde in  milk  in  any  quantity,  or  the  use  of  any  other  preservatives 
in  milk.  I  have  testified  repeatedly  against  the  use  of  sulphite  of 
soda  on  hamburger  steaks." 
I  should  refer  here  again  to  Dr.  Vaughan's  testimony  relating  to 
the  harmfulness  of  benzoic  acid  already  quoted.  If  an  expert  of 
his  experience  is  uncertain  in  regard  to  the  harmfulness  of  two 
