Am.  Jour.  Pharm. 
Dec,  1893. 
Effect  of  Noxious  Gases. 
563 
caused  me  to  make  the  following  experiments  to  satisfy  myself,  an 
accurate  knowledge  on  this  subject  being  necessary  to  the  pursuit  of 
my  profession,  and  I  am  well  aware  of  the  great  difficulties  experi- 
enced by  my  predecessors  in  making  accurate  mixtures  of  gases, 
owing  to  the  crude  appliances  at  their  command  for  this  purpose. 
As  a  prelude  to  my  experiments  I  will  give  the  results  obtained 
with  carbon  dioxide  by  scientists  whom  we  are  accustomed  to  quote  : 
CARBON  DIOXIDE. 
J.  H.  Merrivale  says  it  extinguishes  lights  and  is  fatal  to  animal  life. 
Per  Cent. 
J.  J.  Atkinson  says  dangerous  to  life,  8 
lights  extinguished,  10 
Fairley's  Catechism — dangerous  to  life,   3 
will  cause  death  quickly,  10 
lights  will  burn  in,  10  to  20 
Sir  H.  Roscoes'  Chemistry — will  not  support  combustion  of 
candle,   3  to  6 
Dr.  A.  Smith — lights  extinguished,  about   2 
would  suffocate,   4 
Watts'  Dictionary  of  Chemistry  says  :  "  Animals  immersed  in  it 
soon  die,  not  for  want  of  oxygen,  but  in  consequence  of  a  direct 
poisonous  action,  violent  spasms  being  sometimes  produced  ;  some- 
times complete  atony  of  the  cerebral  faculties." 
Ency.  Brit.,  Vol.  5,  p.  87,  says:  "Will  not  burn;  neither  does 
it  support  combustion." 
Dr.  Karl  Friedlander,  of  Berlin,  in  experiments  on  animal  life, 
states  that  62-8  per  cent,  killed  a  rabbit  in  27  minutes;  65  per  cent, 
killed  a  rabbit  in  45  minutes,  the  higher  per  cent,  in  this  instance 
taking  longer  to  kill  the  rabbit  than  the  lower  per  cent.,  showing  a 
wide  variation  in  his  tests,  which  I  can  only  account  for  in  the  im- 
perfect appliances  at  his  command  for  placing  definite  quantities  of 
gas  in  the  atmosphere  and  maintaining  a  constant  mixture  of  defi- 
nite proportions.  Rabbits,  like  human  beings,  have  their  ailments, 
and  I  have  found  in  the  course  of  my  experiments  that  disease  in 
the  shape  of  a  fatty  accumulation  about  the  heart,  disqualifies 
the  animal  entirely  for  tests  of  this  nature,  death  resulting  in  one- 
tenth  of  the  time  necessary  to  produce  the  same  result  on  a  perfectly 
healthy  animal,  but  in  the  above  instance  the  difference  in  time  of 
immersion  in  such  a  high  per  cent,  is  not  great  enough  for  me  to 
