78 
Why  Popcorn  Pops. 
/Am.  Jour.  Pharm. 
X    February,  1903. 
shell,  we  must  suppose  that  each  individual  cell  is  a  miniature  sealed 
container,  the  walls  of  which  are  sufficiently  dense  to  retain  the  con- 
tained moisture,  until  the  same  has  been  converted  into  steam  under 
pressure.  If  the  residual  moisture  is  sufficient  and  the  conversion 
into  steam  is  uniform  and  rapid,  the  greater  number  of  the  cells  of 
which  the  kernel  is  composed  will  be  exploded  and  the  result  will 
be  a  large,  dry,  mealy  mass  of  converted  cornstarch.  If  the  corn  is 
old  and  dry  it  will  at  best  only  split  open  from  a  number  of  cells 
near  the  centre  of  the  corn  kernel.  If  the  application  of  heat  be 
made  slowly  it  is  possible  to  dry  the  kernels  of  corn,  parch  and  even 
char  them  without  rupturing  the  outer  coat  in  any  way. 
Another  interesting  feature  of  popcorn  may  be  found  in  the  fact, 
that  at  the  base  of  the  kernels,  or  at  the  point  of  attachment  to  the 
cob,  the  cells  are  less  compact  and  are  seldom  if  ever  ruptured  by 
the  generated  steam.  It  is  from  this  point  too  that  the  kernels  of 
corn  appear  to  dry  most  rapidly. 
This  latter  fact  would  appear  to  explain  the  reason  why  popcorn 
is  always  preserved  on  the  cob  and  never  shelled,  as  is  ordinary  fod- 
der corn. 
One  feature  that  appears  to  bear  out  the  theory  of  explosion  by 
steam  is  the  fact  that  popcorn  invariably  bursts  first  at  the  densest 
portion  of  the  kernel,  and  never  at  or  near  its  base  or  point  of 
attachment. 
A  series  of  experiments  that  were  made  appear  to  demonstrate 
the  fact  that  popcorn  loses  considerably  in  weight  by  being  heated. 
Using  corn  from  the  same  cob,  it  was  found  that  the  weight  of  the 
kernels  at  the  several  stages  was  as  follows : 
Whole  or  unpopped  corn,  100  grains  weighed  13-00  grammes. 
Partially  popped  corn,  100  grains  weighed  n-oo  grammes. 
Fully  popped  corn,  100  grains  weighed  9  20  grammes. 
Dried  and  parched  corn,  100  grains  weighed  7-50  grammes. 
The  corn  that  was  used  in  these  experiments  was  rather  old  and 
dry;  the  resulting  popcorn  was  decidedly  tough  and  not  very  light. 
An  attempt  was  then  made  to  see  if  it  were  possible  to  improve  the 
corn  by  moistening.  A  cob  of  approximately  the  same  size  as  the 
one  used  in  the  experiments  noted  above  was  soaked  in  water  for 
twelve  hours,  then  allowed  to  dry  for  twelve  hours.  When  the  corn 
was  shelled  it  was  found  to  be  still  moist.  An  attempt  to  pop  this 
corn  was  not  very  successful,  many  of  the  kernels  being  only  cracked 
