200 
On  Coca. 
Am.  Jour.  Pharm. 
April,  18i8. 
which  I  hold  in  my  left  hand — just  see  what  a  difference  there  is  in  the  form, 
in  the  size  and  in  the  texture  of  the  leaf.  This  specimen  I  collected  under 
peculiar  circumstances. 
There  are  two  rivers  which  unite  at  this  point,  they  come  from  near  the  foot 
of  the  mountain,  one  from  Cuzco,  Peru,  and  the  other  from  La  Paz,  in  Bolivia. 
Now  all  the  way  down  this  river  coming  from  Bolivia  we  find  the  wild  coca 
exists.  It  is  of  the  Bolivian  form,  but  as  soon  as  we  strike  the  other  we  find 
the  larger  leaves,  the  Peruvian  form.  So  that  here  we  have  two  species,  or  not 
two  species,  but  two  varieties. 
Here  wehave  a  form  of  diseased  coca,  called  Taja.  It  is  probably  a  fungus  which 
produces  this  peculiar  condition.  We  know  this  condition  can  be  produced  in 
the  leaf  by  simpl}^  picking  them  carelessly  so  that  the  twigs  are  wounded. 
Then  when  the  new  leaves  are  produced  they  present  this  appearance. 
This  is  a  sufficient  comment  upon  the  idea  which  has  lately  been  advanced 
by  a  writer  to  the  efiect  that  some  of  the  coca  leaves  which  reach 
the  market  are  beaten  off"  from  the  plants  with  poles,  an  opinion  which  is 
evidently  erroneous.  If  an  attempt  were  made  to  beat  the  leaves  from  the 
plant  with  poles,  the  owner  would  never  get  another  crop. 
In  this  specimen  the  lines  are  much  less  prominent  than  in  the  cultivated 
form.  Two  other  forms  of  coca  which  I  have  here,  I  should  rather  say  not  of 
coca,  but  of  Erythroxylon,  are  distinct  species  growing  throughout  the  Eastern 
section  and  even  through  Brazil. 
I  wish, gentlemen,  I  had  time  to  show  you  all  my  specimens.  Perhaps  many 
of  you  would  be  as  much  interested  in  them  as  I  am  myself,  but  it  impossible 
for  me  to  do  so. 
These  two  varieties  of  coca,  the  Bolivian  and  the  Peruvian,  are  so  different 
that  one  Bolivian  writer  has  described  the  Bolivian  form  under  the  name  of 
Erythroxylon  Bolivianum.  The  name,  however,  is  not  correct,  both  are  Ery- 
throxylon Coca.  I  am  not  certain,  however,  that  these  two  cultivated  forms 
have  not  descended  from  distinct  species.  The  two  varieties  are  distinguished 
not  only  by  the  leaves  but  by  the  fruits  which  are  much  larger  in  the  Bolivian 
species,  while  the  leaves  are  much  larger  in  the  Peruvian  species.  The 
Bolivian  variety  is  much  higher  esteemed  by  the  Peruvians,  they  saving 
enough  from  their  scanty  earnings  to  purchase  one-third  of  the  Bolivian  pro- 
duct, although  you  can  obtain  the  native  article  at  a  much  lower  price.  As  you 
are  students  of  Pharmacy,  and  I  think  are  about  to  study  up  the  subject,  per- 
haps a  few  facts  on  the  chemical  constituents  of  the  leaves  might  be  interest- 
ing and  I  will  give  them  to  you  very  briefly. 
You  are  aware  that  there  are  two  methods  of  estimating  the  cocaine  which 
the  coca  leaves  contain.  The  first  is  to  extract  it  in  the  pure  form  and  weigh 
it.  This  method  was  impossible  for  me,  traveling  as  I  was  through  the  coun- 
try and  not  being  able  to  carry  the  necessary  apparatus,  especially  a  balance, 
I  was  therefore  obliged  to  resort  to  the  test  by  titration,  and  this  test  is  about 
as  follows  :  We  obtain  the  cocaine  in  an  aqueous  acid  solution,  about  two  drams 
of  the  solution  representing  two  and  one-half  grams  of  leaves.  This  can  now  be 
tested  with  Mayer's  reagent.  As  the  precipitate  is  formed  this  precipitate  is 
filtered,  and  the  reagent  again  added.  When  no  more  precipitation  occurs  we 
assume  that  the  right  amount  of  reagent  has  been  used,  and  for  every  cubic 
centimeter  so  used  we  have  eight  milligrams  of  cocaine  in  the  leaves.  Now, 
