Am.  Jour.  Pharm. 
Jane,  1398. 
Mucilage  in  Plants. 
285 
In  testing  for  aldehyde,  the  Pharmacopoeia  requires  that  on 
shaking  equal  volumes  of  amyl  nitrite  and  ^  potassium  hydrate, 
the  aqueous  layer  shall  not  be  more  than  pale  yellow.  As  the  table 
shows,  none  of  the  samples  is  fully  up  to  the  standard  in  this 
regard. 
The  writer  wishes  to  acknowledge  valuable  advice  and  aid 
received  from  Dr.  Charles  Rice  and  Prof.  Virgil  Coblentz  in  con- 
nection with  the  subject  of  this  paper. 
Pharmaceutical  Laboratory  of  the  New  York 
College  of  Pharmacy,  May,  1898. 
ORIGIN  AND  DETECTION  OF  MUCILAGE  IN  PLANTS. 
By  Hexry  Kraemer. 
By  the  term  "  mucilage  in  plants "  is  meant  those  substances 
which  are  soluble,  or  at  least  swell  very  perceptibly  in  water,  and 
which,  upon  the  addition  of  alcohol,  are  precipitated  in  a  more  or 
less  amorphous  or  granular  mass.  Mucilage  originates  in  the  plant 
either  as  a  part  of  the  contents  of  the  cell  or  as  a  part  of  the  wall 
thereof.  When  it  occurs  as  a  part  of  the  cell  contents  (as  cell-sap), 
mucilage  is  produced  either  as  an  "  Auscheidung  "  from  the  proto- 
plasm, or  it  may  possibly  arise  in  some  cases  as  a  disorganization 
product  of  some  of  the  contents.  When  it  occurs  as  a  "  membrane 
mucilage,"  it  owes  its  origin  to  several  causes,  viz.:  either  as  a  form 
of  secondary  thickening  or  addition  product  to  the  wall ;  or  as  a 
metamorphosis  of  the  cell  wall,  at  least  in  part.  In  the  latter  case 
it  may  arise  either  as  a  disorganization  product  of  the  primary  wall 
as  an  intercellular  substance  ;  or  of  the  subsequent  lamellae  making 
up  the  pith,  medullary  ray,  parenchyma  and  other  cells.  In  addi- 
tion to  these  two  well- authenticated  cases  of  the  origin  of  mucilage, 
viz.,  as  a  cell  contents  and  cell-membrane,  we  have  mucilage  given 
out  by  some  secreting  hairs  (glands).  In  such  instances  we  can 
simply  say  that  the  mucilage  appears  between  lamellae  of  cutin  on 
the  one  hand  and  of  cellulose  on  the  other  hand,  of  the  epidermal 
cells  of  the  secreting  hair.1 
For  convenience  of  reference,  the  following  table,  containing  some 
1  De  Bary,  Vergleichende  Anatomie,  S.  98. 
