176 
Opuntia  Vulgaris,  Mill. 
(  Am.  Jour.  Pharm. 
\       April,  1896. 
cose  and  -30  per  cent,  of  saccharose.  Neither  gelatin  and  alum 
solution  nor  ferric  chloride  indicated  the  presence  of  tannin.  A 
portion  of  the  water  extract  was  mixed  with  4  volumes  of  abso- 
lute alcohol  and  set  aside  for  twenty-four  hours.  The  precipitate 
of  mucilaginous  and  albuminous  matter  was  collected  on  balanced 
filters,  washed  and  dried.  It  equalled  376  per  cent,  of  the  weight 
of  the  powdered  fruit. 
When  a  weakly  alkaline  water  was  applied  to  the  residue  from 
the  treatment  of  the  powdered  fruit  with  water  and  the  other  three 
solvents,  5-02  per  cent,  of  organic  matter  was  dissolved. 
Some  of  this  alkaline  solution  was  made  slightly  acid  with  acetic 
acid,  and  then  mixed  with  four  volumes  of  absolute  alcohol.  The 
mucilaginous  matter  which  was  precipitated  represented  2*35  per 
cent,  of  the  fruit. 
Water  acidulated  with  hydrochloric  acid  removed  1-91  per  cent, 
of  organic  solids.  This  acid  solution  did  not  contain  phosphates. 
After  the  powdered  fruit  had  been  subjected  to  the  action  of  all  of 
the  foregoing  solvents  in  the  cold,  the  remaining  undissolved  por- 
tion was  washed  free  from  hydrochloric  acid,  and  then  boiled  for 
some  minutes  in  water.  The  mixture  was  allowed  to  become  cold, 
and  a  portion  of  the  water  tested  with  potassium  tri-iodide  for  starch; 
but  this  substance  was  not  found.  The  mixture  was  then  filtered, 
and  after  the  residue  had  been  expressed  to  further  rid  it  of  water, 
it  was  dried,  weighed,  and  finally  incinerated.  The  weight  of  the 
ash  obtained  by  this  operation  was  deducted  from  the  weight  of  the 
residue  before  incineration,  in  order  to  ascertain  the  amount  of  insol- 
uble organic  matter.  The  difference  showed  37  07  per  cent,  of  this 
substance. 
The  stem  was  found  to  contain  8663  per  cent,  of  water  and  -21 
per  cent,  of  ash.  The  constituents  of  this  ash  were  the  same  as 
those  found  in  the  ash  of  the  fruit. 
According  to  the  "  Food  Products  of  American  Indians,"  the 
fruit  of  Opuntia  vulgaris  is  a  favorite  article  of  diet  with  this  race 
of  people.  The  tribes  of  the  southwestern  part  of  the  United 
States  call  the  fruit  by  the  Spanish  name,  "  tunis,"  which  is  more 
than  probably  derived  from  their  use  of  the  fruit  of  Tuna  species. 
They  dry  great  quantities  of  it  for  winter  use.  In  gathering  it  they 
brush  off  the  spines  with  a  bunch  of  grass.  The  Apaches,  however, 
use  wooden  tongs,  or  hooked  sticks,  to  gather  the  fruit.  The 
