Am.  Jour.  Pharm.  ) 
Sept.  1,  1871.  J 
On  Cotton  Seeds, 
387 
The  cotton  seed  oil  is  of  a  mild  taste,  non-drjing  and  congeals  some- 
what below  0°  C.  According  to  Slessor,*  it  consists  marnly  of 
olein  and  palmitin  ;  the  author,  however,  did  not  succeed  to  readily 
prove  the  presence  of  olein  by  testing  with  hyponitric  acid. 
For  technical  purposes,  it  ranks  with  benne  seed  and  olive  oil,  pro- 
yided  it  be  obtained  colorless  or  faintly  yellow.  It  is  exported  in 
large  quantities,  partially  purified,  from  England, f  and  from  Mar- 
seillesj  to  Italy,  whence  it  is  re-exported  as  olive  oil.  50,000  gallons 
of  cotton  seed  oil  were  expressed  in  St.  Louis,  Mo.,  in  1868,  and  a 
factory  in  Providence,  R.  I.  turns  out  a  sweet  golden  yellow  oil,§  the 
process  of  purification  being  kept  secret ;  it  is  probable  that  the  crude 
dark-brown  oil  is  treated  with  lye,  and  a  similar  process  appears  to 
be  in  use  in  Marseilles.  Heated  with  alkalies,  insufficient  for  saponifi- 
cation, most  of  the  color  is  removed,  including  the  coloring  matter 
mentioned  before,  which  may,  perhaps,  be  made  available  for  dyeing. 
Cotton  seed  oil,  in  its  crude  state,  is  colored  purple  by  concentrated 
sulphuric  acid,  and  if  bichromate  of  potassa  be  added  at  the  same 
time,  blood  red  ;  potassa  colors  it  yellowish,  and  in  contact  with  the 
air  finally  bluish  purple.  After  the  first  reaction,  water  will  separate 
a  matter  which  dissolves  with  beautiful  colors,  ranging  between  blue 
and  red,  in  alcohol,  chloroform,  bisulphide  of  carbon,  potassa,  sul- 
phuric acid  and  ether ;  if  these  colors  could  be  fixed  an  excellent  dye 
stufi"  would  be  gained.  This  body  is  probably  formed  by  the  splitting 
of  a  tannin  ;  Kuhlmann||  found  in  it  68*9  carbon  and  8-2  hydrogen. 
Nitric  acid  of  spec.  grav.  1*2  imparts  to  the  purified  oil  a  very  faint 
yellowish  color  ;  a  cold  mixture  of  equal  parts  of  nitric  and  sulphuric 
acid  renders  it  red  brown. 
The  yield  in  oil,  aside  from  the  species  and  from  climatic  influences, 
varies  with  the  treatment  of  the  seeds ;  the  felt  cover,  amounting 
sometimes  to  14  per  cent,  of  the  weight,  if  present  during  the  expres- 
sion, must  retain  considerable  of  the  oil ;  15 — 29  per  cent,  of  oil  have 
been  obtained,  and  after  the  removal  of  the  testa  31  to  over  50  per 
cent.  The  economic  value  of  cotton  seed  rests  mainly  in  the  fact  that 
the  oil  may  be  obtained  in  enormous  quantities  as  a  by-product. 
*Jahresb.  d.  Chemte,  1866,  p.  366,  Gmelin,  Organ.  Chem. 
t  Dingler's  Polytechn.  Journ.,  1865,  p.  236. 
X  Authentic  private  information. 
I  Sold  under  the  name  of  salad  oil. — M. 
II  Jahresber.  d.  Gliemie,  1861,  944, 
