Am.  Jour.  Pharm.  |  jj^^       jj^^^^^        Disease.  457 
hydrocyanic  acid  is  released  as  a  poison.  In  the  circulation  none 
of  the  cyanogen  seems  to  be  released  and  all  of  the  molecules,  if  in 
reasonable  amounts,  are  removed  by  the  kidneys.  These  glucocides, 
therefore,  behave  in  an  exactly  reverse  manner,  so  far  as  their  poi- 
sonousness  is  concerned,  to  that  of  the  food  proteins. 
All  so-called  poisons  appear  to  possess  specific  affinities  for  differ- 
ent kinds  of  cells  just  as  do  the  poisons  let  loose  from  foods  in  anaphy- 
laxis, and  these  are  but  particular  cases  of  the  general  rule  in  all  food 
substances.  The  bone  cells  attract  a  large  share  of  the  lime  of  the 
circulation.  The  liver  cells  take  up  most  of  the  free  sugar  and  deposit 
it  as  glycogen.  The  thyroid  cells  take  charge  of  most  or  all  of  the 
iodine.  The  cells  of  the  choroid  coat  of  the  eye  drag  in  a  large  share 
of  the  melanin.  In  the  same  way  the  nerves  that  supply  the  extensor 
muscles  accumulate  lead  and  produce,  thereby,  wrist-drop.  The 
neurons  of  central  vision  have  an  affinity  for  something  in  tobacco 
that  leads  toward  dim  vision  and  blindness.  Horses  that  have  fed 
on  tobacco  leaves  suffer,  because  of  this,  from  amblyopia.  Methyl 
alcohol  breaks  up,  in  the  circulation,  into  something  that  acts  on 
these  same  neurons  producing  blindness.  Digitalin  and  aconitine 
act  particularly  on  the  heart  muscles.  Curarine  acts  on  the  termini 
of  the  motor  nerves.  Adrenalin  acts  on  the  terminations  of  the 
sympathetic  fibres.  Caffein  has  a  particular  affinity  for  the  kidney 
and  muscle  cells.  Formaldehyde  by  linking  itself  to  the  aminogen 
groups  of  the  protein  is  supposed  to  arrest  metabolism.  Ether, 
chloroform,  cocaine,  morphine,  codeine,  and  heroine  have  an  affinity 
for  lipoids,  being  soluble  in  them,  and  through  this  solubility  are 
thought  to  be  able  to  act  on  the  nerves  of  sensation,  stop  their  func- 
tioning, and  abolish  consciousness  of  pain,  locally  with  some  and 
generally  with  others.  In  quite  small  amounts  these  substances 
all  seem  to  have  but  a  slight  stimulating  effect  upon  the  cells  that 
they  reach  and  act  upon.  A  judicious  use  of  digitalis,  or  of  digitalin, 
strengthens  the  heart  muscles  to  which  they  appear  to  be  attracted. 
A  similar  use  of  atropine  or  belladonna  tones  and  strengthens  non- 
striated  muscles,  stimulates  the  respiratory  centers  and  increases 
intestinal  peristalsis.  Strychnine  is  attracted  to,  and  acts  upon, 
the  vaso-motor  and  motor  centres  of  the  cord,  thus  increasing  the 
circulation  and  producing  thereby  a  general  tonic  effect,  through 
increased  supply  of  arterial  blood.  These,  and  all  other  so-called 
poisons,  when  given  in  proper  amounts,  act  upon  special  parts  of  the 
body — not  to  injure  them — but  to  increase  their  physiological  tone. 
