554 
Insects  Destructive  to  Books. 
{ Am.  Jour.  Pharm, 
\   December,  1910.  ^ 
find  that  rye,  wheat,  and  the  various  other  varieties  of  grain  are 
constantly  being  damaged  by  the  work  of  different  species  of  in- 
sects. These  insects  and  other  small  life  live  upon  the  exudations 
of  plant  life,  and  the  human  body  is  also  giving  off  exudations  in 
the  form  of  perspiration  which  is  also  a  source  of  nourishment  to 
many  forms  of  life. 
We  will  take  rye  and  wheat,  which  are  principally  used  in  paste 
making,  as  an  example.  The  whole  grain  is  taken  to  the  mill, 
husked  and  ground,  and  prepared  by  various  processes  for  the  sus- 
tenance of  the  human  family.  After  all  the  processes  of  the  miller 
have  been  completed,  it  is  barrelled  or  bagged  and  is  ready  for  dis- 
tribution. In  the  processes  we  find  that  alum  has  been  and  is  still 
being  used  as  a  whitening  agency  for  the  different  grains.  The 
flour  is  taken  into  the  factory  apparently  pure,  clean,  and  free  from 
all  forms  of  animated  life ;  but  in  a  very  short  time,  especially  if  it 
is  kept  in  a  compartment  that  is  heated,  or  in  a  moist  atmosphere, 
and  is  left  standing  some  time  before  being  used,  life  is  apparently 
created  in  it,  a  puzzle  to  all,  as  to  its  origin  and  nature,  and  stranger 
still,  the  first  life  noticed  is  always  worm  life.  In  this  case  it  is 
known  as  the  "  flour-worm."  Mr.  James  Stone,  a  flour  merchant 
of  Philadelphia,  in  reply  to  my  questions,  stated  that  they  always 
discovered  the  worms  first,  that  they  were  only  found  in  the  centre 
of  the  barrel,  never  near  the  sides,  and  that  the  loose  flour  laying 
around  the  floors,  of  which  there  always  was  a  quantity,  was  never 
found  to  have  worms  in  it.  The  lower  or  coarser  grades  which  are 
used  exclusively  for  paste  were  first  damaged.  The  finer  grades 
were  more  seldom  found  to  be  affected.  This  goes  to  prove  my 
theory  that  the  life  was  in  the  flour  before  grinding,  and  that  it  lay 
dormant  until  the  proper  conditions  were  produced,  such  as  heat  and 
dampness.  The  grinding  of  these  grains  allows  the  gases  in  the  air 
to  reach  the  particles  which,  to  a  large  extent,  were  before  protected 
by  skin  or  husk.  These  gases  cause  a  chemical  change  to  take 
place,  which  has  been  little  studied,  and  this  will  be  found  to  give 
food  for  forms  which  were  heretofore  in  a  dormant  condition. 
Many  eggs  of  the  smaller  forms  of  life  can  hardly  be  seen,  even 
with  a  compound  microscope.  The  following  are  some  of  the 
species  that  may  be  classed  as  paste  eaters :  Pyralis  farinalis,  a  moth, 
and  Tenebroides  mauritanicus,  Silvanus  surinamensis,  Calandra  gra- 
naria,  and  Tenebrio  molitor,  all  beetles. 
Paper. — Paper  is  made  from  cotton,  linen3  hemp,  rags,  and 
