144 
ON  FALSE  ISINGLASS. 
most  distinctly  to  observe  the  formation  of  iodide  of  starch.  The 
presence  of  an  iodide  may  be  shown  in  a  still  more  marked  man- 
ner, by  suspending  the  stem  of  the  same  plant  in  a  dry  atmos- 
phere, when  the  surface,  after  the  lapse  of  some  hours  or  days, 
will  become  covered  with  numerous  transparent  crystals,  which 
on  examination  will  be  found  to  consist  principally  of  chlorides, 
but  at  the  same  time  to  contain  so  much  of  an  iodine  compound 
as  to  impart  an  intense  blue  color  to  the  test-mixture. 
Many  marine  plants,  when  placed  in  a  fresh  state  in  contact 
with  the  test-mixture,  impart  an  orange  color  to  it,  owing  to  the 
liberation  of  bromine. —  Quart.  Journ.  of  Ohcm.  Soc,  iv.  p.  155. 
A  FALSE  ISIXGLASS  FROM  PARA. 
A  substance  has  lately  been  imported,  under  the  name  of 
Isinglass,  which,  on  examination,  proves  not  to  be  isinglass,  but 
the  dried  ovary  of  a  large  fish. 
Two  boxes  were  imported  :  they  did  not  contain  more  than  14 
or  16  lbs.  A  similar  article  has  been  before  imported  into 
London.  They  somewhat  resemble  a  bunch  of  grapes  ;  and 
consist  of  ovoid  or  rounded  masses,  attached  by  peduncles  to  a 
central  axis ;  by  immersion  in  water  this  axis  is  found  to  consist 
of  a  convoluted  membrane,  to  one  side  only  of  which  these  ovoid 
masses  are  attached. 
A  very  superficial  examination  of  this  so-called  isinglass, 
proves  that  it  is  neither  the  swimming  bladder  of  a  fish,  nor  is  it 
gelatinous  ;  but  it  is  in  reality  the  ovary  of  some  large  fish,  and 
is  of  an  albuminous  nature.  When  soaked  in  water  its  fishy 
odor  becomes  very  obvious. 
The  ovoid  masses  are  ova.  They  are  highly  vascular  on  the 
surface,  and  are  filled  with  an  animal  substance  of  a  yellow 
color.  In  general  appearance  they  resemble  the  vitellus  of  a 
shark  or  ray. 
The  Sudis  Gyas,  a  large  osseous  fish,  upwards  of  six  feet  in 
length,  is  found  at  Para.  Its  flesh  is  dried,  salted,  and  eaten 
by  the  lower  classes;  and  its  swimming  bladder  constitutes  one 
of  the  kinds  of  Brazilian  isinglass  imported  into  London.  It  is 
probable,  therefore,  that  the  ovary  of  this  fish  constitutes  the 
false  isinglass  in  question.  If  not  from  this  fish,  it  is  probably 
obtained  from  some  allied  genus  (as  Amia)  of  highly  organized 
osseous  fishes. — Pharm.  Journ.,  Jan.  1,  1853. 
