Am  Jour.  Pharm. 
Sept.,  1891. 
Sterilized  Milk. 
445 
THE  CHEMISTRY  AND  CLINICAL  VALUE  OF 
STERILIZED  MILK. 
Of  late  years  a  great  deal  has  been  written  upon  the  dangers  of 
transmission  of  infection  by  means  of  milk  derived  from  diseased 
animals  or  improperly  handled  or  exposed,  and,  as  a  consequence, 
sterilization  has  been  regarded  as  a  necessity ;  but  the  milk,  after  ster- 
ilization has  been  found  to  be  so  changed  in  that  process  that  of 
late  a  reaction  has  set  in,  and  the  question  has  arisen  whether  or 
not  the  desired  immunity  could  not  be  better  attained  by  some 
other  means.  In  the  American  Journal  of  the  Medical  Sciences  for 
June,  1 891,  Professor  A.  R.  Leeds  and  Dr.  E.  P.  Davis  contribute  a 
valuable  paper  as  to  the  nature  of  the  changes  effected  in  milk  by 
sterilization  and  the  clinical  value  of  sterilized  milk. 
Professor  Leeds  is  well  known  as  an  authority  on  the  subject  of 
milk  analysis,  and  his  conclusions  are  extremely  interesting  and 
valuable.  Dr.  Leeds  finds  that  raising  the  temperature  to  the  boil- 
ing point,  and  still  more  the  retaining  of  it  at  that  point  for  a 
lengthened  period,  as  in  sterilization,  converts  a  considerable  portion 
of  the  soluble  into  insoluble  proteids.  The  effect  of  heat  is  greatest 
on  the  galactozymase — the  ferment  found  in  raw  milk,  which  has  the 
power  of  liquefying  starch;  even  raising  milk  for  a  moment  to  the 
boiling  point  destroys  this  ferment  action.  Experiments  made  to 
contrast  the  behavior  of  sterilized  milk  with  raw  milk,  when  sub- 
jected to  the  action  of  rennet,  acid,  artificial  gastric  juice,  and  pan- 
creatic juice,  show  that  the  casein,  while  not  coagulated  by  the  heat,  is, 
nevertheless,  less  readily  coagulated  by  rennet,  and  yields  slowly  to 
the  action  of  pepsin  and  pancreatin.  Moreover,  a  part  of  the  lact- 
albumen  of  the  milk  is  coagulated,  although  only  partially  so.  Its 
effect,  however,  is  to  thicken  the  milk  and  intensify  its  colloidal  (ropy 
or  mucilaginous)  character.  The  fat  globules  are  likewise  somewhat 
affected  by  the  heat,  and  the  coagulated  proteid  matters  attach  them- 
selves to  the  fat  globules,  and  probably  have  an  influence  in  bring- 
ing about  the  difficulty  with  which  the  fat  is  assimilated. 
Finally,  milk-sugar,  Dr.  Leeds  finds,  is  completely  destroyed  by 
long-continued  heating,  and  is  probably  affected  to  a  certain  extent 
during  the  interval  ordinarily  allowed  for  sterilization.  Dr. 
Leeds  thus  shows  that  sterilized  milk  is  less  readily  and  less 
perfectly  digestible  than  raw  milk,  and  if  sterile  milk  is  sought 
for,  the  present  desideratum  is  to  obtain  it  either  directly  from 
