l^-}Cat  Method  for  Tcstiui^  Digitalis,  Etc. 
487 
cat  method  where  No.  416233  is  decidedly  more  active  than  No. 
335929,  the  reverse  of  what  was  found  by  the  frog  heart  method. 
Attention  should  be  called  to  the  lot  of  animals  used  for  No. 
335929,  which  was  perhaps  the  least  suitable  of  any.  It  may  be 
noticed  that  the  greater  number  were  females,  varying-  considerably 
in  size,  some  being  in  different  stages  of  lactation.  (No.  6  was  in 
the  early  stage  and  had  exceptionally  large  glands.)  The  males 
were  all  large  and  the  results,  perhaps  a  coincidence,  varied  some- 
what in  relation  to  the  weight : 
The  assays  on  the  two  samples  of  strophanthus  seed  are  almost 
identical  by  the  frog  heart  method,  and  show  but  a  small  difference 
by  the  cat  method. 
Animals. — Hatcher  and  Brody  selected  cats  in  preference  to 
dogs,  and  I  believe  rabbits,  for  several  reasons,  namely :  "  Accuracy 
afforded,  facility  with  which  they  may  be  obtained,  ease  with  which 
they  may  be  handled,  cheapness,  and  the  fact  that  their  use 
does  not  affect  the  sensibilities  of  the  sentimental  portion  of  the 
community  to  the  same  extent  that  the  employment  of  the  dog 
does."  Having  used  no  other  animals  for  this  particular  method,  I 
cannot  remark  on  the  point  of  accuracy.  My  experience  has  been 
that  there  is  little  in  their  favor  regarding  cost,  all  things  considered. 
Cats  are  easily  handled,  though  to  my  mind  are  no  more  so  than 
dogs,  or  rabbits,  except  that  in  the  case  of  the  latter  greater  care  is 
necessary  in  regard  to  any  dissection  or  the  giving  of  anaesthetics. 
I  have  found  them  far  more  difficult  to  obtain  than  rabbits  and  hardly 
less  so  than  dogs.  Whether  their  use  affects  the  sensibilities  of  the 
sentimental  portion  of  the  community  less  than  that  of  the  dog 
seems  questionable.  At  any  rate,  the  use  of  cats  certainly  does 
affect  the  sensibilities  of  niany  people,  and  the  ]:)rocuring  of  a  suffi- 
cient number  of  animals  for  this  piece  of  work  has  been  the  source 
of  considcral)le  troul)lc.  And  for  a  manufacturing  \)\^ni  of  this  size, 
to  secure  enough  cats  to  carry  out  the  routine  assays  on  the  several 
members  of  the  digitalis  series,  would  l)c  a  ])ractical  imj^ossibility. 
If  some  easily  procurable  animal  such  as  the  ra1)l>it  could  ])e  used  for 
Weight 
Result 
•140,3 
.127,8 
.090,8 
No.  2 
No.  8  , 
No.  10 
3.18  Kgms. 
3.00  Kgms. 
2.46  Kgms. 
Discussion. 
