■^l?ay^^9'2":}    Pharmacology  of  Cotton  Root  Bark.  287 
made  from  commercial  lots  of  drug,  by  extraction  with  50%  alcohol. 
The  pituitary  extracts  used  in  comparative  tests  were  either  samples 
of  commercial  extract,  or  laboratory  extractions  of  commercial  lots 
of  glands. 
METHODS. 
It  was  decided  to  test  the  activity  of  cotton  root  barks  by  the 
methods  commonly  employed  for  the  testing  of  ergot,  namely,  the 
cock's  comb,  blood  pressure,  and  uterus  methods.  These  methods 
as  carried  out  in  this  work  are  briefly  as  follows : 
cock's  comb  method. 
The  cock's  comb  method  consists  in  administering  to  pure-bred, 
single-comb,  white  leghorn  roosters,  by  injection  into  the  pectoral 
muscles,  gradually  increasing  or  diminishing  doses  of  fluidextract 
until  a  slight  but  distinct  and  unmistakable  bluing  of  the  comb  points 
has  been  produced.  This  method  is  simple  and  rapid,  and  has  been 
reported  as  giving  results  which  seem  to  run  closely  parallel  to  those 
obtained  by  the  intact  uterus  method.  Perhaps  no  other  method  is 
so  commonly  employed  for  the  testing  of  ergot.  The  end-point, 
unlike  that  of  the  other  methods,  is  a  purely  visual  one. 
BLOOD  PRESSURE  METHOD. 
The  blood  pressure  method  consists  in  recording  the  change  in 
carotid  pressure  caused  by  the  intravenous  injection  of  the  fluid- 
extract  by  way  of  the  saphenous  vein.  Young,  medium  sized  dogs 
are  the  subjects  preferred.  These  have  seemed  to  give  the  most 
satisfactory  records  when  anaesthetized  with  morphine  sulphate 
(0,010  to  0.012  G.  per  Kg.)  and  hyoscine  hydrobromide  (0.000,064 
to  0.000,128  G.  per  Kg.).  Ether  is  used  for  the  operation  of  inserting 
cannulae,  etc.,  but  is  withdrawn  as  soon  as  the  apparatus  is  set  up  and 
running.  Artificial  respiration  is  established  in  all  cases.  The  com- 
mon mercury  manometer  was  employed  in  this  work.  The  doses  of 
fluidextract,  calculated  per  Kg.  of  body  weight,  were  diluted  for  in- 
jection with  one  or  two  times  their  volume  of  salt  solution. 
A  few  experiments  were  carried  out  on  decapitated  dogs  and  cats, 
prepared  according  to  the  method  of  Sherrington.^ 
The  blood  pressure  method,  essentially  as  described,  is  a  com- 
monly employed  laboratory  method  for  studying  the  effect  of  drugs 
on  the  circulation.  It  has  been  used  extensively  for  determining 
the  pressor  effect  of  preparations  of  ergot. 
