174 
The  Manna  of  Scripture. 
Am.  Jour.  Pharm. 
March,  1920. 
THE  MANNA  OF  SCRIPTURE.* 
By  E.  M.  H01.MES,  F.L.S. 
The  recent  discussion  in  The  Chemist  and  Druggist  concerning 
the  nature  and  origin  of  the  manna  of  the  Israehtes  has  led  me  to 
venture  to  express  the  opinion  of  a  botanist  on  the  subject,  for  to  a 
student  of  that  science,  especially  to  an  economic  botanist,  the  sub- 
ject presents  an  exceedingly  interesting  problem. 
The  description  given  by  the  Jewish  historian  in  the  Pentateuch 
does  not  exactly  fit  in  with  any  known  vegetable  production,  and 
the  various  plants  or  plant  products  with  which  manna  has  been 
doubtfully  identified  from  time  to  time  cannot  reasonably  be  con- 
sidered by  any  botanist  to  meet  the  requirements  of  the  case. 
The  plant  that  has  most  generally  been  accepted  as  being  the 
manna  of  Scripture  is  a  lichen,  Lecanora  esculenta,  var.  mannifera, 
Ehrenb.,  which  is  abundant  on  stones  and  rocks,  and  in  certain 
stages  of  its  growth  is  broken  up  by  drought  and  violent  winds  into 
small  particles,  which  collect  in  quantity  under  the  lee  of  small 
bushes  which  arrest  its  career,  or  is  carried  away  by  rainstorms  and 
deposited  in  wave-like  furrows  in  sandy  desert  ground  in  consider- 
able quantities.  An  illustration  of  this  plant  is  given  in  Kerner  and 
Oliver's  "Natural  History  of  Plants,"  Vol.  I,  p.  195,  and  a  description 
of  its  curious  growth  and  distribution  in  Vol.  II,  pp.  810,  811.  Two 
other  species  are  mentioned  as  being  found  mixed  with  it — viz., 
Lecanora  desertorum  and  Lecanora  Jussufii. 
Lecanora  esctdenta  is  abundant  from  Persia  and  Asia  Minor  to 
Algeria  and  the  Sahara  in  North  Africa.  But  this  lichen  differs 
from  manna  in  not  appearing  with  the  dew,  not  breeding  worms 
and  not  stinking  if  kept  for  two  days.  I  have  had  a  specimen  of 
it  in  my  possession  for  over  thirty  years,  and  it  is  as  hard  and  solid 
as  when  it  first  came  into  my  possession.  It  is  obvious,  therefore, 
that  it  cannot  be  the  manna  of  Scripture,  as  it  does  not  possess  any 
of  its  characters.  It  may  be  useful  to  quote  here  the  actual  descrip- 
tions given  in  the  Pentateuch  of  the  appearance  of  manna.  The 
best  account  of  it  occurs  in  Exodus  xvi,  14-36,  which  reads  thus: 
"And  when  the  dew  was  gone  up,  behold,  upon  the  face  of  the  wil- 
derness a  small  round  (or  flake),  small  as  the  hoar  frost  upon  the 
ground  "  Moses  said,  "Gather  ye  of  it  every  man  accord- 
*  The  Chemist  and  Druggist,  January  3,  1920. 
