ON  NEW  ENGLAND  ISINGLASS. 
517 
an  expression  is  proper,  I  would  again  suggest  the  value  of  ex- 
perimenting with  the  air  vessels  of  sturgeon  taken  from  some 
colder  rivers  of  our  country,  with  a  view  of  equalling  the  pro- 
duct of  Russia. 
I  was  surprised  to  learn  that  the  demand  for  New  England 
isinglass  was  very  limited,  and  unless  some  large  increase  in 
its  consumption  should  occur,  there  appears  to  be  no  induce- 
ment for  others  to  engage  in  its  manufacture. 
We  find  the  preparation  of  this  article,  then,  to  be  a  very  sim- 
ple process ;  nothing  more  than  certain  membranous  parts  of 
fishes,  divested  of  adhering  mucus  and  dried  in  the  air.  The 
peculiar  arrangement  of  the  fibres  of  the  article  has  doubtless 
attracted  your  attention,  and  this  elongation  is  readily  explained 
when  the  process  of  its  manufacture  is  understood. 
In  speaking  of  the  yield  of  isinglass  from  the  sturgeon  of 
Russia,  the  "  Acipenser  huso"  of  Linnaeus,  Mr.  Jackson  says, 
(in  apparent  opposition  to  the  general  impression,  which  is,  that 
the  sturgeon  on  account  of  its  cartilaginous  nature  would  yield 
great  quantities  of  isinglass,)  that  no  part  of  the  fish  except  the 
inner  coat  of  the  sound,  or  air  vessel,  promised  the  least  suc- 
cess ;  this  being  so  full  of  "  rugse,"  adheres  so  firmly  to  the 
external  membrane,  which  is  useless,  that  the  labor  of  separat- 
ing supersedes  the  advantage. 
The  intestines,  however,  which  in  larger  fish  are  several  yards 
in  length,  being  cleansed  from  their  adhering  mucus  and  dried, 
are  found  surprisingly  strong  and  elastic,  resembling  cords 
made  from  the  intestines  of  animals  known  as  "  cat  gut,"  and 
promised  to  be  of  some  practical  utility. 
The  characteristics  need  scarcely  be  noticed  here.  The  best 
is  a  whitish,  dry,  tough,  semi-transparent  substance,  unchange- 
able in  the  air,  of  a  leathery  aspect  and  a  mawkish  taste,  nearly 
insipid.  When  steeped  in  cold  water  it  swells,  softens  and 
separates  in  membranous  iaminse.  At  the  boiling  point  it  dis- 
solves in  water,  forming  when  cooled  a  white  jelly,  which  is 
semi-transparent,  soluble  in  weak  acids,  but  precipitated  from 
its  solution  by  alkalies.  It  is  gelatin  nearly  pure,  and  if  not 
brittle,  like  other  glue,  it  is  because  of  its  elastic  texture. 
The  uses  of  isinglass  are  various  and  important.  The  princi- 
pal consumption  is  for  "fining"  liquors,  beer,  wine,  &c, ;  and 
