REMARKS  ON  GUM  MEZQUITE. 
15 
dant  tree  of  the  plains,  and  covers  thousand  of  miles  of  surface.  From  them 
the  gum  exudes  spontaneously  in  a  semi-fluid  state,  and  hardens  in  a  few- 
hours,  forming  more  or  less  rounded  lumps  of  various  shades  of  color,  and 
weighing  each  from  a  few  grains  to  several  ounces.  These  soon  bleach  and 
whiten  by  exposure  to  the  light  of  the  sun,  finally  becoming  semi-transpa- 
rent, and  often  filled  with  minute  fissures. 
The  quantity  yielded  by  each  tree  varies  from  an  ounce  to  three  pounds, 
but  incisions  made  in  the  bark  not  only  greatly  facilitates  its  exudation, 
but  causes  the  tree  to  yield  a  much  greater  amount.  The  gum  may  be  col- 
lected during  the  months  of  July,  August  and  September,  but  the  most 
favorable  period  for  that  purpose  is  in  the  latter  part  of  August,  when  it 
may  be  obtained  in  the  greatest  abundance  and  with  but  little  trouble.  By 
proper  care  and  attention,  I  am  of  the  opinion  that  a  sufficient  quantity 
may  be  annually  obtained  not  only  to  supply  the  home  market,  but  to  ad- 
mit of  a  large  surplus  for  exportation.  I  have  employed  the  gum  medi- 
cinally in  several  instances,  and  find  it  answers  the  purpose  cf  the  best 
gum  acacia  ;  with  water  it  forms  a  beautiful  mucilage,  while  for  a  proof  of 
its  great  tenacity  I  will  refer  you  to  this  package  with  which  it  is  sealed. 
I  would  be  pleased  to  hear  from  you  upon  the  subject. 
Respectfully  yours, 
Geo.  G.  Shumard,  M.I). 
Surgeon  and  Geologist  to  Capt.  R.  B.  Marcv's  Expedition  to  Brazos  and  Witchita  Rivers. 
To  Charles  Ellis,  President  of  the  Philada.  College  of  Pharmacy. 
Dr.  Shumard,  in  a  letter  to  Hon.  Thos.  S.  D.  Drew,  of  the 
Indian  Agency,  uses  the  following  language,  viz : 
"  Sir, — I  cheerfully  comply  with  your  request  to  furnish,  for  the  use  of 
the  Indian  Department,  a  short  description  of  the  gum  mesquite,  discovered 
during  our  recent  expedition  to  the  head  waters  of  the  Big  Wachita  and 
Brazos  rivers. 
"  This  gum,  for  which  I  propose  the  name  of  gum  mezquite,  is  believed 
to  occur  in  inexhaustible  quantities,  and  will  no  doubt  prove  a  source  of 
revenue  to  the  State  of  Texas,  New  Mexico  and  the  adjacent  Indian  terri- 
tory, besides  affording  employment  to  the  different  tribes  of  Indians  now 
roving  upon  the  plains,  many  of  whom  would  no  doubt  be  glad  to  gather 
and  deliver  it  to  the  different  frontier  posts  for  a  very  small  compensation." 
The  specimen  of  gum  sent  to  Mr.  Ellis  consists  of  tears  of 
various  sizes,  and  degrees  of  purity,  from  colorless  to  dark  amber 
color.  The  pieces  are  much  fissured,  like  the  true  gum  acacia, 
and  even  the  darkest  pieces,  when  broken,  soon  exhibit  the  ten- 
dency to  crack  into  fragments.  Many  of  the  pieces  have  parti- 
cles of  bark  attached  to  them.  The  sp.  gravity  of  the  solid  lumps 
is  1-311?  which  is  about  the  same  as  that  of  gum  arabic.  Putin 
