228  The  Pharmaceutical  Chemist.       { AmxJ°iir'  £ J1™' 
to  our  supposed  "  law."  For  example,  pyrocatechol  (ortho-dihy- 
droxy-benzene)  is  more  poisonous  than  its  monomethyl  derivative, 
guaiacol,  which  in  turn  is  more  potent  than  the  dimethyl  derivative, 
veratrol.  Apparently  we  are  on  the  road  to  prove  that  alkylation 
of  a  hydroxy  group  in  aromatic  compounds  decreases  the  toxicity, 
but  presently  we  find  that  from  resorcinal,  which  is  meta-dihydroxy- 
benzene,  we  obtain  a  dimethyl  derivative  that  is  very  much  more 
toxic  than  the  parent  substance  and  our  interesting  theory  suffers 
a  rude  shock. 
If  now  we  cautiously  advance  along  some  of  the  blazed  trails  in 
the  jungle  of  organic  compounds,  hoping  fervently  that  harsh  and 
unrelenting  facts  will  not  pounce  upon  and  tear  to  pieces  some  of 
our  nicely  domesticated  pet  theories,  we  discover  some  rather 
astonishing  things.  Take  adrenalin,  which,  as  derived  from  its 
natural  source,  is  levorotatory.  When  prepared  synthetically  it  is 
racemic  and  much  less  active  than  the  naturally  occurring  form. 
Further  investigation  shows  that  the  dextrorotatory  form  is  only 
about  one-twelfth  as  powerful  in  increasing  the  blood  pressure  as 
the  levorotatory  form.  The  peculiar  effect  of  the  atropine  group 
of  alkaloids  in  dilating  the  pupil  of  the  eyes  is  about  fifteen  times 
as  great  in  levohyoscyamine  as  in  its  stereoisomer.  Atropine  and 
cocaine  are  not  widely  different  chemically,  both  being  derivatives 
of  the  nucleus  tropine,  but  while  some  points  of  likeness  may  be 
found  in  their  physiological  action,  there  are  many  and  pronounced 
differences,  for  instance,  cocaine  is  a  powerful  local  anesthetic,  while 
atropine  is  devoid  of  this  effect.  Again,  cocaine  is  methyl-benozyl- 
ecgonine  and  ecgonine  has  no  local  anesthetic  properties,  while 
neither  benzoyl-ecgonine  nor  ecgonine-methyl  ester  have  more  than 
a  very  slight  effect  of  this  kind.  And  so  we  go,  gradually  accumu- 
lating a  great  store  of  isolated  facts  and  laboriously  fitting  them 
together.  We  are  very  like  the  child  with  a  jig-saw  picture  puzzle: 
we  fit  together  a  few  facts  here  and  a  few  more  over  there  and 
occasionally  have  to  take  apart  some  which  do  not  fit  perfectly, 
hoping  that  some  day  we  will  get  enough  of  this  picture  together  to 
find  out  what  it  really  looks  like. 
Turning  for  a  moment  to  other  questions,  how  shall  we  deter- 
mine the  medicinal  activity  of  aconite  preparations?  The  drug  con- 
tains one  important  and  highly  toxic  alkaloid,  aconitine,  but  also  vary- 
ing amounts  of  related  alkaloids  which  are  not  only  much  less  toxic 
but  in  some  cases  actually  antagonistic  in  their  action  to  the  aconi- 
