CHANGES  IN  THE  BLOOD  BY  COD-LIVER  OIL,  ETC.  421 
All  these  precipitates  are  particularly  adapted  for  the  fabrica- 
tion of  marbled  papers  and  paper-hangings  ;  for  if  the  mixture 
of  the  size,  glaze,  and  color  is  well  effected,  the  metallic  lustre 
makes  its  appearance  even  on  rubbing  with  a  stiff  brush. 
As  a  guide  in  the  preparation  of  these  colors,  I  give  the  fol- 
lowing formulae  : — 
1.  10  lbs.  of  good  Brazil-wood  are  deprived  of  their  coloring 
matter  by  repeated  decoction  in  river-water,  and  the  collected 
decoctions  left  standing  for  from  four  to  eight  days  in  an  open 
wooden  tub.  The  clear  decoction  is  then  poured  away  from  the 
sediment,  and  put  again  into  a  clean  vessel.  Part  of  it  is  then 
heated,  and  whilst  hot  5  lbs.  of  alum  are  dissolved  in  it,  and  the 
solution  is  mixed  with  the  remainder.  The  precipitate  will  have 
collected  in  about  eight  days ;  it  is  strained  through  cloth  till  it 
acquires  a  pasty  consistence,  and  preserved  for  use  in  that  form. 
2.  10  lbs.  of  logwood  are  boiled  twice  with  river-water,  and 
the  strained  decoction  evaporated  to  one-half  in  the  kettle  ;  10 
oz.  of  chloride  of  tin  are  then  added,  and  the  precipitate  is 
strained  through  cloth. 
3.  The  decoction  is  prepared  and  concentrated  as  before,  and 
10  oz.  of  alum  are  added  to  it,  and  allowed  to  dissolve  ;  powdered 
bichromate  of  potash  is  then  sprinkled  in  gradually  as  long  as  a 
sample  taken  out  and  laid  on  paper  still  appears  dark  blue ;  for 
this  purpose  1 J  oz.  are  generally  required.  Too  much  of  the  bi- 
chromate of  potash  renders  the  color  black,  and  spoils  it.  This 
is  also  strained  through  cloth. — Chem.  Gaz.,  July 1854,  from 
Dingier 's  Polyt.  Journ.,  cxxvi.  p.  433. 
ON  THE  CHANGES  PRODUCED  IN  THE  BLOOD  BY  THE  ADMIN- 
ISTRATION OF  COD-LIYER  OIL  AND  COCOA-NUT  OIL. 
Br  Theophilus  Thompson,  M.D.,  F.R.S. 
The  author  has  found  that  during  the  administration  of  cod- 
liver  oil  to  phthisical  patients  their  blood  grew  richer  in  red  cor- 
puscles, and  he  refers  to  a  previous  observation  of  Dr.  Franz 
Simon  to  the  same  effect.  The  use  of  almond-oil  and  of  olive- 
oil  was  not  followed  by  any  remedial  effect,  but  from  cocoa-nut 
oil  results  were  obtained  almost  as  decided  as  from  the  oil  of  the 
liver  of  the  Cod,  and  the  author  believes  it  may  turn  out  to  be  a 
