Am.  Jour.  Pharm.  ) 
January,  1921.  j 
Spiders  Used  in  Medicine. 
21 
to  the  exterior  through  silk  ducts,  which  often  open  on  movable, 
finger-shaped  "spinneretts." 
In  all,  spiders  produce  seven  distinct  kinds  of  silk;  some 
thread-like,  some  band-like,  some  viscid,  some  dry.  Though  most 
spiders  secrete  more  than  one  kind  of  silk,  and  some  spiders  secrete 
several  kinds,  no  one  spider  secretes  all  seven.  Each  kind  of  silk 
originates  in  its  own  distinct  glands  and  passes  to  the  exterior 
through  its  own  opening.* 
For  pharmaceutical  preparations  an  attempt  is  made  to  collect 
the  sheet-like  webs  of  Coras  medicinalis  (Tegenaria  medicinalis) 
from  the  corners  of  rooms  in  warehouses  and  kindred  places.  It 
is  probable,  however,  that  the  webs  of  the  several  species  of 
dwelling-inhabiting  spiders  enter  into  all  pharmaceutical  prepara- 
tions of  web.  No  collector  of  webs  could  be  expected  to  possess 
technical  knowledge  sufficient  to  enable  him  to  distinguish  species. 
If  he  should  possess  the  required  knowledge,  it  would  be  imprac- 
ticable for  him  to  take  the  time  to  apply  his  training  for  the  ex- 
amination of  each  web  collected.  Nor  is  there  need  for  such  dis- 
crimination. No  reason  why  the  web  of  one  species  of  dwelling- 
inhabiting  spider  should  be  of  different  therapeutical  qualities  from 
another,  has  ever  been  recorded. 
We  do  not  know  that  a  chemical  analysis  of  spider  web  has 
ever  been  made.  Tests  given  pharmaceutical  preparations,  how- 
ever, show  an  absence  of  sugar,  but  give  a  slight  reaction  to 
Mayer's  test  for  alkaloid.  This  is  true  also  of  tincture  we  have 
prepared  from  fresh  web.  The  therapeutic  value  of  the  prepara- 
tion may  be  in  part  due  to  this  alkaloid. 
In  the  present-day  practice  of  medicine  the  large  spiders  of  the 
sub-family  Aviculariinae,  commonly  known  as  "tarantulas,"  or 
"bird  spiders,"  are  employed  by  Homoeopathic  physicians.  Under 
the  name  of  My  gale  lasidora  the  Pharmacopoeia  of  the  American 
Institute  of  Homoeopathy,  1897,  page  408,  gives  directions  for 
preparing  the  tincture  of  the  "whole  spider."  Other  references  to 
the  preparation  and  use  of  Mygale  (tarantula)  are  given  in  Allen's 
"Encyclopedia  of  Pure  Materia  Medica,"  Vol.  VI,  1877,  and  else- 
where. 
*A  careful  and  interesting  account,  written  in  non-technical  language, 
of  the  habits,  anatomy  and  classification  of  spiders,  may  be  found  in  The 
Spider  Book,  by  John  Henry  Comstock.   Doubleday,  Page  &  Co.,  1912. 
