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PRODUCTION  OF  MANNITE  BY  MARINE  PLANTS. 
The  action  of  acids  upon  analogous  bodies  having  given  rise 
to  decompositions  producing  peculiar  principles  and  glycose,  I 
endeavored  to  ascertain  the  presence  of  the  latter  in  the  mother- 
liquors  from  which  the  crystals  of  colchiceine  were  deposited, 
but  I  only  succeeded  in  isolating  a  resinous  matter,  insoluble  in 
water,  combined  with  some  coloring  matter  and  very  soluble  in 
alkalies,  a  product  consequently  of  an  acid  nature.  The  characters 
of  this  resinous  matter  are,  that  it  is  soluble  in  alcohol  and  ether, 
acquires  a  blood-red  color  with  nitric  acid,  and  dissolves  in  am- 
monia, to  which  it  also  gives  an  intense  red  color. 
Physiological  Experiments. — According  to  experiments  made 
by  Prof.  Schroff*  of  Vienna,  the  colchicine  obtained  according 
to  the  process  of  Hess  and  Geiger  has  a  poisonous  action  upon 
rabbits  even  in  doses  of  0-01  grm. ;  the  animal  only  dies  in  from 
twelve  to  eighteen  hours.  Given  in  large  doses,  even  of  1  grm., 
it  does  not  produce  death  in  less  than  seven  or  eight  hours.  When 
colchiceine  is  injected  into  the  stomach  in  a  dose  of  0-01  grm., 
the  animal  does  not  die  for  ten  or  twelve  hours,  but  in  a  dose  of 
5  centigrms.  it  causes  a  complete  paralysis  of  the  members  and 
death  in  a  few  minutes  Chemical  Gazette,  March,  1857,  from 
Comptes  Rendus,  Dec,  1856. 
ON  THE  PRODUCTION  OF  MANNITE  BY  MARINE  PLANTS. 
By  Dr.  T.  Phipson. 
It  has  been  for  some  time  known  that  certain  marine  algae 
produce,  when  dried  in  the  open  air,  efflorescences  of  mannite 
(sugar  of  manna)  on  their  surface.  Of  this  number  are  Lami- 
naria  saccharina,  D.  digitata,  Rhodomenia  palmata,  Fucus 
siliquosus,  F.  nodosus,  F.  vesiculosus,  F.  saccharinus,  F.  ser- 
ratus,  &c.  In  1855,  I  observed  this  production  of  mannite  on 
many  of  these  algae  (which  are  very  common),  and  especially  on 
the  Laminaria  saccharina,  the  Fucus  vesiculosus,  and  its  numer- 
ous varieties,  the  F.  serratus.  I  have  no  doubt,  that  all  the 
algae  which  contain  vegetable  mucilage  produce  this  substance, 
when  in  conditions  favorable  to  its  formation. 
*  Oesterreich,  Zeitschr.  fur  prakt.  Heilkunde,  June  6,  1856. 
