5 1 6  Stan day dilation  of  A  drenalin .        j  Amjl™  ri92i arm' 
only  by  this  means  that  its  efficacy  can  be  established.  Detailing  his 
ten  years'  experience  in  handling  adrenalin  and  preparations  of  the 
suprarenal  gland,  M.  TifTeneau  described  his  researches,  and  the 
methods  adopted  for  the  evaluation  of  these  products.  The  most  re- 
liable method  of  establishing  the  physiological  activity  of  adrenalin 
consists  in  comparing  in  the  same  animal  the  variations  in  the  arterial 
blood  pressure  produced  by  injections  of  these  products.  An  adrena- 
lin of  absolute  purity  and  full  activity  is  used  as  the  standard.  For 
these  tests  the  dog  is  found  most  suitable,  and  the  animal  is  first 
anaesthetised  and  then  given  an  injection  of  atropine  sulphate  in  the 
proportion  of  one  milligram  for  every  kilogram  of  body  weight. 
Without  entering  into  the  details  of  the  test,  minutely  described  by 
the  author,  it  may  be  stated  that  it  is  based,  first  of  all,  upon  establish- 
ing by  a  series  of  tentative  injections  of  a  1 :  10,000  solution  of  the 
standard  adrenalin  the  most  convenient  increase  in  blood  pressure 
produced,  which  is  6  cm.  to  8  cm.,  corresponding  to  an  increase  of 
pressure  of  12  cm.  to  16  cm.  of  mercury.  It  was  generally  found 
that  this  was  effected  by  a  dose  varying  between  2/100  and  6/100  of 
a  milligram  of  standard  adrenalin.  As  a  result  of  his  exhaustive  re- 
searches, M.  TifTeneau  was  able  to  establish  that  natural  laevogyrate 
adrenalin  possesses  a  vasoconstrictive  action  which  is  more  than 
double  that  of  the  racemic  (synthetic)  product,  the  exact  relation- 
ship being  1  =  0.46,  and  from  this  may  be  inferred  the  dangers  at- 
tending the  use  of  a  product  not  possessing  the  full  activity  of  the 
official  substance,  particularly  in  the  case  of  so  active  a  drug.  In  de- 
scribing his  investigations  on  various  preparations  of  the  suprarenal 
glands,  in  the  form  of  a  desiccated  powder,  and  as  extracts  of  the 
glands,  the  author  stated  that  he  had  established  that  one  kilo,  of 
fresh  suprarenal  gland  obtained  from  horses  contained  on  an  average 
2  grams  of  adrenalin.  Since  the  loss  incurred  in  desiccation  and  by 
removing  the  fat  amounts  to  about  80  per  cent.,  it  follows  that  100 
grams  of  desiccated  suprarenal  gland  corresponds  to  500  grams  of 
fresh  gland  (of  horses),  and  contains  1  gram  of  adrenalin,  the 
standard  also  adopted  by  the  United  States  Pharmacopoeia.  With 
one  exception,  the  commercial  products  complied  with  this  standard, 
and,  indeed,  some  samples  examined  showed  a  slightly  higher  con- 
tent of  adrenalin.  Of  interest  is  the  observation  that  if  carelessly 
stored — i.  e.,  kept  in  imperfectly  closed  bottles  and  exposed  to  light — ■ 
desiccated  preparations  ,of  the  suprarenal  gland  at  the  end  of  a  year 
show  a  loss  of  about  50  per  cent,  of  their  original  content  of  adrena- 
