INFLUENCE  OF  HYPODERMIC  INJECTION,  ETC.  41 
which  had  solved  some  of  the  great  astronomical  problems,  the 
phenomena  of  the  animal  organism  were  a  sealed  book. 
Albinus  took  no  meagre  view  of  organic  activity  in  nature 
when  he  established  the  axiom  that  the  essence  of  life,  or  the 
vital  force,  consisted  in  motion. 
Changes  are  continually  going  rapidly  forward  in  the  living 
body  ;  physical  forces  are  always  striving  for  the  equilibrium ; 
the  matter  set  in  motion  by  them  finds  its  centre  of  gravity — its 
point  of  rest.  Force  is  nothing  more  than  the  expression  of  the 
causal  action  of  natural  laws ;  and  if  facts  do  not  accord  with 
our  laws,  we  have  either  formed  false  opinions,  or  have  imper- 
fectly investigated  the  different  circumstances  under  which  they 
were  exhibited. 
Within  the  past  few  years  the  science  of  toxicology,  as 
developed  by  the  German  and  French  chemists,  has  attained  an 
accuracy  which  is  surprising,  when  we  contemplate  the  crude 
state  it  was  in  fifty  years  ago.  But  rapidly  as  has  been  its 
progress,  there  has  suddenly  arisen  a  barrier  to  its  advance,  more 
formidable  than  any  it  had  to  meet  before. 
Friedberg  and  Ritter  mournfully  acknowledge  that  the  day 
has  not  yet  arrived  when  we  can  detect  the  difference  between 
dried  human  and  ox  blood.  A  few  enthusiasts  have  claimed  a 
peculiar  odor  to  different  kinds  of  blood ;  but  these  tests  stood 
on  so  slender  a  foundation,  and  required  an  almost  hyper-excited 
nose  to  detect  them,  that  no  conscientious  expert  will,  for  one 
moment,  depend  on  it  for  convicting  the  criminal.  The  micro- 
scope, with  its  polarizing  prism,  is  not  able  to  distinguish 
between  the  most  of  domesticated  animals'  blood  and  that  of 
man,  after  it  has  been  dried  any  length  of  time. 
We  are  not  able  at  the  present  day  to  detect  absorbed 
alkaloidal  poisons,  and  that  is  the  fact  forming  the  subject  of 
this  essay,  and  to  which  I  wish  most  particularly  to  call  your 
attention.  There  can  be  no  doubt  that  these  powerful  agents, 
of  which  strychnia  and  morphia  are  the  types,  are  absorbed  into 
the  blood,  and  diffused  throughout  the  system,  like  other  poisons. 
There  seems  to  be  a  want  of  unity  in  the  statements  relative  to 
their  deposition  in  the  viscera,  and  their  subsequent  elimination. 
M.  Stas,  in  1847,  announced  the  discovery  of  the  alkaloid  in 
