^™or\88r™'  }       ^ciive  Principle  of  Adonis  Vernalis.  497 
zoate  of  soda  (288),  one  equivalent  of  caffeine  (244),  or  48*5  per  cent, 
of  caffeine. 
The  double  salt  richest  in  caffeine  can  be  obtained  with  salicylic 
acid.  An  equivalent  of  salicylate  of  soda  (160)  allows  of  the  solution 
of  an  equivalent  of  caffeine  (244),  which  gives  61  per  cent,  of  caffeine 
in  this  double  salt. 
The  solubility  of  these  double  salts  is  such  that  solutions  can  be 
easily  obtained  with  the  benzoate  and  cinnamate  of  soda  containing  20 
centigrams  per  cubic  centimeter,  and  with  salicylate  of  soda  as  much 
as  30  centigrams. 
Benzoic,  cinnamic  and  salicylic  acids  having  supplied  me  with  what 
I  was  in  search  of,  I  have  not  thought  it  necessary  to  ascertain  to  what 
extent  analogous  results  might  be  obtained  by  employing  those  acids 
in  combination  with  other  bases  than  soda.  I  may  mention,  however, 
that  I  have  been  able  to  obtain  double  salts  with  acetic,  lactic,  citric, 
sulphuric  and  hydrochloric  acids. 
With  these  new  salts,  therefore,  it  will  be  possible  in  future  to 
administer  caffeine  hypodermically.  It  is  true  that  the  alkaline  salts 
associated  with  it  have  their  own  peculiar  action ;  but  this  action  is 
known,  and  consequently  it  will,  according  to  the  case  and  the  dose, 
sometimes  be  ignored  and  sometimes  taken  account  of ;  that  will  be  a 
matter  of  therapeutics. 
In  conclusion,  these  salts  may  always  be  prepared  extemporaneously 
by  simple  solution  in  water  in  the  proportions  given  above.  But  since 
the  commercial  benzoate  of  soda  has  sometimes  an  alkaline  reaction, 
it  will  be  as  well,  in  preparing  hypodermic  injections,  to  first  neutra- 
lize the  soda  salts  with  the  corresponding  acids. — Phar.  Jour,  and 
Trans.,  Aug.  5,  1882,  from  Jour,  de  Phar..  1882,  v.  591. 
THE  ACTIVE  PEINCIPLE  OF  ADONIS  VERNALIS. 
By  Dr.  V.  Ckrvello. 
The  use  of  the  Ranunculaceous  plant,  Adonis  vernalis,  L.,  in  some 
forms  of  heart  disease  has  led  to  some  physiological  experiments  from 
which  it  would  appear  that  it  is  capable  of  exercising  an  action  similar 
to  that  of  digitalis,  with  the  advantage  that  it  is  not  cumulative,  its 
administration  during  a  considerable  time  being  without  danger.  But 
hitherto  nothing  definite  has  been  known  with  respect  to  the  constituent 
32 
