94  Notes  on  Some  Saps  and  Secretions.  { ^febr^imT' 
Catechu  is  us^d  in  medicine  as  a  gentle  tonic  and  a  powerful  astrin- 
gent, on  account  of  the  large  quantity  of  tannic  acid  (50  per  cent.) 
which  it  contains.  Combined  with  opium  it  answers  a  good  purpose 
as  an  internal  remedy  in  chronic  diarrhoea,  catarrh  or  dysentery. 
Cutch  is  not  specified  in  the  American  imports,  but  gambier  is 
named,  but  appears  among  gums,  with  the  old  misnomer  of  "Terra 
japonica."  The  quantity  imported  fluctuates  between  27,000,000 
and  35,000,000  pounds. 
Sugars. — The  maple  tree,  several  palms,  the  white  beet  root, 
sorghums,  the  sugar  cane,  and  other  plants  and  trees,  yield  saccharine 
saps,  but  as  the  product  of  these  have  chiefly  dietetic  uses,  rather 
than  medicinal,  I  shall  not  enter  into  details  on  them. 
Aloes  Species. — The  simply  inspissated  juice  of  the  leaves  of 
various  species  of  this  gum  constitutes  the  "  aloes  "  drug  of  phar- 
macy. It  is  best  obtained  by  using  neither  heat  nor  pressure  for 
extracting  the  sap.  By  redissolving  the  aqueous  part  in  cold  water 
and  reducing  the  liquid  through  boiling  to  dryness,  the  extract  of 
aloes  is  prepared.  All  species  are  valuable  in  localities  where  they 
are  hardy,  and  can  be  used  (irrespective  of  their  medicinal  import- 
ance) to  beautify  any  rocky  or  otherwise  arid  spot. 
Aloe  Ferox,  Lamarck. — This  yields  the  best  Cape  aloes,  as  observed 
by  Dr.  Pappe.  Other  species,  such  as  A.  pcrfoliata,  Lin.,  also  yield 
the  drug.  A.  africana,  Mill.,  and  A.  plicatis,  Mill.,  and  A.  commelini, 
Salm.,  are  said  to  yield  a  less  powerful  kind. 
The  following  are  also  South  African  species :  A.  arborescens, 
Miller;  A.  lingnceformis,  Mill.;  A.  angulata,  Willd.  From  this 
species  the  purest  gum  resin  is  obtained. 
A.  purpitrascens,  Haworth,  is  one  of  the  plants  which  furnish  the 
Cape  aloes  of  commerce.  A.  spicata,  Lin.,  also  provides  Cape  aloes. 
A.  Zeyheri,  Harvey,  a  magnificent,  very  tall  species,  is  doubtless  valu- 
able like  the  rest.  A.  soccotrina,  Lamarck.,  is  also  indigenous  to  South 
Africa;  A.  dichotoma,  Lin.  fil.,  in  Damara  and  Namaqualand,  at- 
tains a  height  of  30  feet  and  expands  occasionally  with  its  branches 
so  far  as  to  give  a  circumference  of  40  feet.  The  stem  is  remarkably 
smooth,  with  a  girth  sometimes  of  12  feet.  It  is  a  yellow-flowering 
species.  A.  Bainesii,  Baker  and  Dyer,  is  almost  as  gigantic  as  the 
foregoing.  Both,  doubtless,  yield  the  medicinal  gum  resin,  like 
several  others. 
In  many  parts  of  the  Colony  of  Natal,  a  wild  aloe  is  very  abund- 
