290  Pharmacology  of  Cotton  Root  Bark.     {^"^  ^ Zay^^Q^: 
teen  samples  were  then  given  to  fowls,  the  combs  of  which 
had  previously  been  blued  by  small  doses  of  ergot.  From  the 
results  shown  in  Table  3  it  may  be  seen  that  none  of  the  thir- 
teen samples  were  distinctly  active  in  bluing  the  comb  in  doses 
of  3  c.c.  per  Kg.  This  dose  is  four  times  the  amount  which 
was  required  of  fluidextract  of  ergot  to  produce  a  distinct 
bluing  in  the  same  fowls.  Testing  by  the  cock's  comb  method 
was  therefore  discontinued. 
Table  3 
Tests  on  Samples  of  Different  Varieties  of 
Cotton  Root  Bark,  Collected  at  Flowering 
Cock's  Comb  Method 
Dose 
Sample      Fowl     Weight     per  Kg.  Results 
No.  1         540        2.000        2  c.c.      No  noticeable  bluing  of  comb. 
 544        1.713        3  c.c.   "      "  "  
No.  2         535        1.424        2  c.c.        "         "  "      "      "    (?)  (Cold) 
 548        1.785        3  c.c.  
No.  3         545        1.921         2  c.c.        "         "  "      "      "  (Redder) 
 540        1.404        3  c.c.   "      "  "  
No.  4         541        1.852        2  c.c.        "         "  "      «      «  (Redder) 
 541        1.923        3  c.c.  
No.  5         554        1.703        2  c.c.        "         "  "      "      "  (Redder) 
 535        1.547        3  c.c.   "      "  "  
No.  6         548        1.908        2  c.c.        "         "  "  " 
 545        1.924        3  c.c.   "  "    Warm  red 
No.  7         540        1.957        2  c.c.        "         "  "      "      "    (?)  (Cold) 
 541        1.981         3  c.c.   "  "    (?)  (Cold) 
No.  8         541        1.859        2  c.c.        "         "  "      "      "    (?)  (Cold) 
 540        2.106        3  c.c.   "      "      "    (?)  (Cold) 
No.   9        545        1.871         2  c.c.      No  noticeable  bluing  of  comb. 
 548        1.776        3  c.c.   "    (?)  (Cold) 
No.  10        545        1.342        2  c.c. 
544        1.746        3  c.c.        "         "  "      "      "    (?)  (Cold) 
No.  11 
535 
1.342 
2  c.c. 
u 
«  u 
535 
1.584 
3  c.c. 
u 
a 
u  « 
"    (?)  (Cold) 
No.  12 
544 
1.678 
2.  cc. 
u  u 
539 
1.716 
3  c.c. 
u 
u  u 
"    (?)  (Cold) 
546        1.775        3  c.c.      Extremely  faint  bluing  of  comb  (?) 
In  the  cases  marked  (?)  there  seemed  to  be  a  mere  suggestion  of  bluing,  so 
faint,  however,  that  it  could  not  be  distinguished  with  certainty.    No.  13  with 
3  c.  c.  was  the  most  pronounced  of  these. 
BLOOD  PRESSURE  EXPERIMENTS. 
Before  presenting  the  results  of  blood  pressure  experi- 
ments on  cotton  root  bark,  results  cf  normal  blood  pre?sures 
of  anaesthetized  dogs  were  observed  in  order  to  determine 
with  what  regularity  the  normal  pressure  would  run  when 
recorded  by  the  method  and  apparatus  employed.  Such  re- 
sults may  be  seen  in  Table  4.  Slight  variations  in  pressure 
would  probably  be  recorded  with  the  best  of  apparatus  and 
under  the  most  careful  technic.  Occasionally,  however,  more 
pronounced  changes  may  be  caused  by  a  slight  movement  of 
the  animal  as  happened  in  experiment  786.  A  somewhat  more 
