134  Notes  on  Some  Saps  and  Secretions.  { AmiLJ^p^fm- 
Fraxinus  ornus,  Lin.;  F.  rotundifolia,  Lam.;  Orni/s  Europcea, 
Pers.;  or  Ornus  rotundifolia.  The  sweet  exudation,  known  as 
<(  Manna,"  is  chiefly  the  concrete  juice  obtained  by  incising  the  bark 
of  the  ash  and  collecting  it  on  pieces  of  stick,  hence,  called  flaky 
manna.  The  best  is  in  oblong,  light,  friable  pieces,  of  a  whitish 
color  and  somewhat  transparent,  with  a  sweetish,  sharp  taste  and  a 
weak  smell.  The  inferior  kinds  are  moist,  unctuous  and  dark- 
colored.  It  is  a  mild  aperient  medicine.  Each  hectare  (of  two  and 
one-half  acres)  planted  with  the  ash — 4,000  to  5,000  trees — pro- 
duces on  an  average  nearly  2,000  pounds  of  manna.  It  used  to  be 
produced  in  Calabria,  but  that  exported  comes  chiefly  now  from 
Palermo,  in  tin  boxes  weighing  about  14  pounds.  Small  flake- 
manna  is  sent  out  in  cases  of  about  120  pounds,  large  flake-manna, 
in  cases  of  half  that  size.  The  export  of  manna  from  Italy,  in 
1884,  was  about  446,000  pounds.  Spurious  manna  is  known  by  its 
uniform  color  and  freedom  from  the  slight  impurities,  as  well  as 
from  the  peculiar  odor  and  slight  bitterness  of  true  manna. 
Calabria  was,  many  years  ago,  the  only  source  of  the  manna  of 
commerce,  but  the  production  there  has  ceased,  and,  as  stated 
above,  Sicily  is  now  the  chief  seat  of  production.  Manna  is  nutri- 
tious, particularly  when  recent.  It  is  a  mild  laxative,  does  not 
excite  inflammation,  useful  for  children  and  delicate  females,  usually 
operating  mildly,  but  in  some  cases  produces  flatulence  and  pain. 
In  certain  cases,  the  leaves  of  Larix  Europcea  exude  a  species  of 
manna  called  "  Manna  of  Briancon,"  which  is  eaten  in  Russia. 
Another  kind  is  from  Tamarix  mannifera,  and  the  Oriental  manna 
of  the  desert  from  Alhagi  mauromm,  DeC,  A.  mannifera,  Desf. 
The  sugary  secretion  obtained  naturally  from  this  plant  is  chiefly 
collected  in  Khorasan,  Kurdistan  and  Hamadan,  and  imported  into 
Bombay.  As  a  medicine  its  effects  correspond  to  those  of  the  ash 
manna. 
The  Arabs  who  cross  the  deserts  avail  themselves  of  the  manna  of 
the  camel's  thorn  [Alhagi  camelorum,  Fisch.).  It  is  found  in  the 
morning  on  the  ground  round  the  plant,  during  several  days  of  the 
summer,  and  is  collected  before  the  sun  can  melt  it.  It  occurs  in* 
small,  round,  unequal  grains,  the  size  of  coriander  seed,  of  a  yellow- 
ish white  or  greenish  yellow  color,  caking  together  and  forming  an 
opaque  mass,  in  which  are  found  portions  of  the  thorns  and  points 
of  the  plant.    This  manna  is  inodorous,  its  flavor  is  sweetly  saccha- 
