"^NoVSrfJgTr}        Insects  Destructive  to  Books.  511 
affected  by  the  light  given  off  by  the  sulphur,  warns  it  of  the 
danger,  and  as  a  consequence  it  seldom  eats  a  poison  that  is  placed 
near  its  haunts.  This  Bureau  made  a  very  large  series  of  experi- 
ments in  order  to  obtain,  if  possible,  a  binding  material  which 
would  be  exempt  from  the  inroads  of  insects,  and  also  to  withstand 
the  effects  of  light  and  gases  without  fading,  and  which  Prof.  S.  W. 
Stratton,  the  Director  of  the  Bureau,  very  kindly  loaned  me  for 
study.  The  tests  were  made  with  cloths,  ducks  and  buckrams  of 
various  colors.  A  portion  of  each  piece  was  chemically  analyzed 
in  order  to  find  what  substances  were  used  in  their  manufacture, 
and  the  rest  of  each  sample  was  exposed  to  the  roaches  for  various 
numbers  of  days.  The  results,  when  tabulated,  proved  that  it  did 
not  seem  to  make  any  difference  as  to  what  materials  were  used  in 
the  coating,  many  of  which  were  poisonous,  as  they  had  nibbled  all 
but  one  of  the  bindings.  They  then  tried  impregnating  some  of 
the  samples  with  a  weak  solution  of  quinine  and  others  with 
strychnine,  but  these  failed  to  give  the  desired  immunity;  and,  upon 
increasing  the  quantity  of  the  poison  in  the  solution,  the  attractive- 
ness of  the  substances  was  increased.  Even  corrosive  sublimate  was 
ineffective.  It  is  true  that  the  insects  died  within  a  few  days,  but 
not  until  they  had  ruined  the  bindings.  One  sample,  seeming  to 
be  exempt  from  their  ravages,  was  selected  and  adopted  by  the 
Bureau  as  a  standard  for  binding  the  United  States  Congressional 
documents,  and  also  accepted  by  the  American  Library  Association 
Committee  on  Book-Binding  as  the  best  binding  for  library  books. 
During  a  conversation  in  the  Government  Printing  Office  last 
winter,  while  being  shown  the  various  materials  used  for  binding 
Government  documents,  I  expressed  doubts  as  to  the  buckram 
approved,  known  as  No.  666,  being  insect-proof ;  and  this  opinion 
has  since  been  confirmed  by  experiments  made  by  the  Philippine 
Bureau  of  Science,  Dr.  Stratton  and  myself. 
My  own  experiments  with  a  poison  of  an  entirely  different  char- 
acter gave  better  results.  One-half  of  each  of  the  various  kinds 
of  binding  materials  tested  was  treated  with  my  preparation  and 
the  other  half  left  untouched.  They  were  placed  in  boxes  and 
exposed  to  the  attacks  of  the  roaches  for  various  periods.  Upon 
examination,  I  found  that  while  the  coloring  matter  in  certain 
samples  had  been  eaten  on  both  the  treated  and  untreated  portions, 
the  poisoned  portions  of  quite  a  number  of  the  others  were  left 
alone.    In  some  cases  pieces  of  the  same  color,  although  of  different 
