ON  HAIR  AND  HORNY  SUBSTANCES. 
147 
sure  off  this  quantity  correctly  for  the  final  operations,  which 
consisted  in  precipitating  the  quinine  therefrom  by  means  of  a 
solution  of  caustic  soda,  slightly  washing  the  precipitat#  with 
distilled  water,  redissolving  it  in  alcohol,  and  after  filtering  the 
alcoholic  solution,  evaporating  it  to  dryness  in  a  water  bath.  The 
residue  was  then  weighed  and  examined  in  the  usual  manner,  to 
ascertain  if  it  were  quinine. 
I  need  scarcely  explain  that  the  sulphate  of  soda  in  the  acid 
solution  is  employed  to  effect  the  more  ready  and  complete  se- 
paration of  the  watery  fluid  from  the  oily  one,  and  that  the 
sulphuric  acid  is  added  to  dissolve  out  and  combine  with  the 
quinine  which  exists  in  the  oil  in  (if  I  may  use  the  term)  a 
caustic  condition. 
From  experiments  made  with  cod-liver  oil  with  quinine,  pre- 
pared by  myself,  of  known  strength,  I  feel  justified  in  observing 
that  the  method  described  gives  sufficiently  accurate  results  to 
be  relied  on  for  all  practical  purposes. 
In  cases  where  other  alkaloids  have  to  be  detected  and  esti- 
mated, the  process  of  separation  to  be  employed  would  be  pre- 
cisely similar  to  that  described  for  the  separation  of  quinine. 
When  separated,  they  will  of  course  be  recognized  by  the  methods 
laid  down  in  the  text  books  on  chemical  analysis. 
In  conclusion,  I  may  add  that  the  quantity  of  sulphuric  acid 
employed  in  this  process  should  be  sufficient  to  render  the  aqueous 
fluid  slightly  acid  after  it  has  been  well  agitated  with  the  oil 
containing  the  alkaloid,  and  that  the  proportion  of  the  extract- 
ing fluid  may  be  varied,  in  accordance  with  the  convenience  of 
the  operator,  and  the  nature  and  quantity  of  the  alkaloid  to  be 
extracted — London  Pharm.  Journ.  Nov.  1856. 
CHEMICAL  RESEARCHES  ON  HAIR  AND  HORNY  SUBSTANCES. 
By  M.  Von  Bibra. 
It  has  long  been  admitted,  that  the  color  of  hair  and  fur  is  not 
due  to  a  coloring  matter,  but  that  it  depends  on  the  structure  of 
the  appendages.  This  is  also  confirmed  by  Von  Bibra's  re- 
searches, in  which  he  vainly  endeavored  to  extract  the  coloring 
matter.  On  this  point,  microscopy  may  give  more  information 
than  chemistry. 
