532         Preparations  of  the  Suprarenal  Glands.  {AxovJembefhi9oim' 
pharmacologic  activity,  owing  to  the  liability  to  undergo  chemical 
or  bacteriological  decomposition  before,  during,  or  after  manufac- 
ture, in  the  various  products  that  were  to  be  obtained  on  the  market. 
Believing  that  the  results  of  my  observations  may  be  of  some 
interest  to  members  of  the  Association,  I  will  briefly  outline  the 
method  that  has  given  me  the  best  results.  This  method  is  based 
upon  the  changes  produced  in  the  blood  pressure  of  the  carotid 
artery  when  variable  quantities  of  a  given  preparation  of  the  supra- 
renal glands  dissolved  in  slightly  acidulated  water,  the  inert  sub- 
stance being  removed  as  far  as  possible,  are  injected  into  the 
femoral,  or  jugular  vein,  of  an  anaesthetized  dog  or  other  animal. 
The  apparatus  required  are  an  operating  table  suitable  for  experi- 
8 
c 
\  A 
Ik 
°-25  is"  ft"  }2eC 
Fig.  i. — Blood-pressure  tracing  taken  from  the  carotid  artery  of  a  dog  anes- 
thetized with  chloretone.  Suprarenal  liquid  diluted  with  normal  saline  solution 
to  5  c.c.  in  each  instance  was  slowly  injected  into  the  femoral  vein. 
When  injected  into  the  circulation  the  principle  of  the  suprarenal  gland 
causes  a  marked  temporary  rise  in  the  blood-pressure.  The  height  of  the 
waves  in  the  above  tracing  (indicating  the  amount  of  pressure  in  the  carotid 
artery)  is  directly  proportionate  to  the  quantity  of  adrenalin  injected  in  each  in- 
stance. For  example,  at  A  is  shown  the  effect  of  the  administration  of  0*25 
c.c.  of  suprarenal  liquid  ;  at  B,  of  0*5  c.c.  ;  at  C,  of  1  c.c.  ;  and  a±D,  of  2  c.c 
menting  on  dogs,  and  such  surgical  instruments  as  are  usually  found 
in  physiological  and  pharmacological  laboratories,  including  small 
glass  conulae,  suitable  for  inserting  in  blood-vessels  and  veins  and  a 
syringe  of  10  c.c.  capacity.  A  large-sized  kymograph,  with  mano- 
meter arranged  for  taking  blood-pressure  tracings  on  continuous 
rolls  of  white  paper,  with  ink  pens,  or  fitted  with  the  more  con- 
venient smoked-paper  sheets,  upon  which  the  results  are  traced  with 
a  stylus  is  required.  In  either  case,  whether  smoked  or  unsmoked 
paper  is  employed,  for  convenience  in  making  measurements  of  the 
height  of  the  blood-pressure  tracings,  the  paper  should  have  linear 
rulings,  five  millimeters  apart. 
The  method  is  as  follows:  A  small  or  medium-sized  dog  is  care- 
