COETEX  WINTERANUS  AND  GANELLA  ALBA.  27 
If  platina-black  is  made  into  a  paste  with  a  concentrated 
solution  of  mannite,  the  mixture  assumes  at  a  moderate  heat, 
after  several  days,  a  peculiar  odor,  resembling  valerianic  acid  ; 
in  oxygen,  carbonic  and  acetic  acids  are  formed ;  but  by  active 
oxygen,  a  fixed  acid  is  produced  which  yields  a  precipitate 
with  acetate  of  lead,  and  was  isolated  as  a  brown  amorphous 
mass. 
One  part  of  mannite  was  distilled  with  30  p.  water,  1  p.  sul- 
phuric acid  and  1  p.  binoxide  of  manganese ;  the  distillate  con- 
tained acroleine  and  formic  acid ;  carbonic  acid  is  likewise 
evolved. 
The  mucilage  of  manna  was  obtained  by  repeatedly  dissolv- 
ing it  in  water  and  precipitating  by  strong  alcohol  ;  the  precipi- 
tate with  acetate  of  lead  has  the  composition  3PbO,  ^-zJ^icfi-zo  5 
the  formula  of  the  mucilage  agrees  with  Leuchtweiss's  results, 
who  calculated  C^H^O^.  By  dilated  nitric  acid,  mucic  acid 
was  obtained  which  has  the  same  composition  as  that  analyzed 
by  Liebig,  which  was  obtained  from  gum  arabic.  Bouillon- 
Lagrange  obtained  the  mucic  acid  from  the  mucilage  of  manna 
as  early  as  1819,  (^Ann.  de  Chim.  et  de  Phys.  iv.  10)  ;  but  it  is 
interesting  that  it  may  be  obtained  also  from  other  compounds 
than  carbohydrates. 
The  sugar  which  remains  in  the  alcoholic  mother  liquids 
cannot  readily  be  obtained  free  from  mannite  ;  but  it  seems  to 
be  identical  with  grape-sugar,  for  it  is  crystalline  ;  its  solution 
deviates  polarized  light  to  the  right,  is  readily  fermentable  by 
yeast,  reduces  alkaline  solution  of  copper  in  the  cold,  and  turns 
10  a  yellowish-brown  color,  when  heated  with  caustic  soda. 
J.  M.  M. 
ON  CORTEX  WINTERANUS  AND  GANELLA  ALBA. 
Canella  alba,  Murr.,  growing  in  theWest  Indies,  is  supposed  to 
be  the  origin  of  the  Canella  alba  of  commerce,  and  Wintera 
aromatica,  Murr.  s.  Drymis  winteri,  Forst.,  of  Patagonia,  the 
plant  yielding  the  commercial  Winter's  bark.  On  account  of 
their  similarity,  the  former  has  been  sometimes  called  Cortex 
Winteranus  spurius,  and  both  have  been  frequently  mistaken 
for  one  another. 
