Am.  Jour.  Pharm.  ) 
Nov.  1, 1873.  j" 
Preservation  of  Food. 
495 
saltpetre,  and  sugar  or  molasses,  this  last  being  the  method  by  which 
the  well-known  sugar-cured  hams  of  the  "West  are  prepared.  The 
use  of  salt  and  other  chemicals  is  objectionable,  from  the  fact  that 
they  more  or  less  impair  the  original  flavor  of  the  meat,  and  if  the 
provisions  prepared  in  this  way  are  indulged  in  for  a  length  of  time 
they  are  apt  to  produce  disease.  The  action  of  salt  has  never  been 
thoroughly  explained  ;  salt  and  sugar  are  supposed  by  some  to  owe 
their  preservative  effects  to  the  fact  that  they  abstract  water  from 
the  article  to  be  preserved  ;  others  claim  that  salt  acts  by  coagulating 
the  albuminoid  bodies  which  give  rise  to  putrefaction;  while  still  a 
third  class,  including  most  of  the  prominent  investigators  in  this 
line  of  research,  allege  that  salt,  carbolic  acid,  creasote  and  similar 
articles  act  as  a  poison  to  infusoria  and  thus  prevent  the  commence- 
ment of  decay. 
Shortly  after  the  discovery  of  oxygen,  it  was  observed  that  if  oxy- 
gen in  a  free  state  was  completely  excluded  from  animal  or  vegetable 
matter,  they  might  be  preserved  for  an  indefinite  length  of  time. 
This  fact,  like  many  others,  had  been  used  blindly  and  imperfectly  for 
ages.  The  bodies  of  men  and  animals  had  been  preserved  in  cloths 
saturated  with  pitch  and  rosins,  and  the  great  were  buried  in  leaden 
coffins,  hermetically  sealed.  But  no  practical  use  of  this  fact  seems 
to  have  been  made  until  the  year  1807,  when  a  patent  was  granted  in 
England  for  pouring  a  hot  solution  of  gelatin  or  meat  extract  over 
the  meat,  so  as  to  completely  exclude  the  air.  This  has  since  been  a 
favorite  method  with  inventors,  who  have  endeavored  to  preserve 
meats  by  covering  them  with  various  impervious  substances,  but  they 
have  not  generally  proved  very  successful,  it  being  exceedingly  diffi- 
cult to  keep  such  coverings  intact. 
The  patent  which  may  be  said  to  have  given  rise  to  the  modern 
industry  of  packing  meat  and  vegetables  in  air-tight  cans  was  one 
granted  in  England  to  Peter  Durand,  in  August,  1810.  The  main 
points  of  this  patent  are  as  follows  : 
First. — Preserving  animal  food,  vegetable  food  and  other  perishable  articles 
a  long  time  from  perishing  and  becoming  useless,  by  excluding  all  communica- 
tion with  the  external  air.  The  articles  are  enclosed  in  bottles,  or  other  vessels 
of  glass,  pottery,  tin,  or  other  metals  or  fit  materials,  and  they  are  closed  by 
the  usual  methods  of  corking,  soldering,  luting  or  cementing.  Further,  making 
use  of  vessels  with  stoppers  fitted  or  ground  with  emery,  or  screw  caps,  with 
or  without  a  ring  of  leather  or  other  soft  material  between  the  faces  of  closure, 
or  with  covers  of  cloth,  leather,  parchment,  bladder  and  the  like. 
