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LITMUS  PAPER. — FLBUR  DE  GARANCE,  ETC. 
PREPARATION  OF  LITMUS  PAPER. 
By  A.  Yacher. 
I  have  had  much  trouble  in  obtaining  a  thoroughly  satisfactory 
litmus  paper.  When  used  with  blotting  paper  it  is  not  as  deli- 
cate as  could  be  wished,  and  on  one  occasion,  when  attempting  to 
make  it  with  sized  paper,  the  blue  tincture  persistently  turned 
red  when  it  touched  the  paper.  The  latter  reaction  seemed  to 
be  due  to  the  sizing  material,  and  it  occurred  to  me  that  if  I 
sized  some  paper  myself  with  pure  gelatin,  my  object  would  be 
obtained. 
I  can  recommend  the  following  receipt : 
"  Digest  20  grm.  litmus  with  100  c.  c.  water  for  some  time, 
shaking  occasionally  ;  then  filter.  To  the  filtrate  add  a  slight 
excess  of  nitric  acid,  and  boil ;  then  neutralize  exactly  with  pot- 
ash. Now  make  a  weak  solution  of  gelatin  by  boiling  1  part  of 
isinglass  with  50  parts  of  water ;  draw  white  blotting  paper 
through  this,  and  hang  it  up  to  dry.  When  dry,  paint  one  side 
with  the  above  solution  of  litmus. 
20  Great  Marlborough  Street,  May  30. 
— London  Chem.  News,  June  5,  1868. 
ODORIFEROUS  PRINCIPLE  OF  FLBUR  DE  GARANCE  AND 
GARANGINE  ALCOHOL. 
It  is  a  well  known  fact  that  when  ground  madder  root  is  pre- 
paied  into  garancine,  or  fleur  de  garance,  a  saccharine  liquor  is 
obtained  which,  on  fermentation  and  distillation,  yields  an  alco- 
hol which  is  contaminated  with  what?  for  years  past,  was  con- 
sidered to  be  methyl  alcohol.  More  recent  researches  have 
brought  out  the  fact  that  the  peculiar  odor  of  the  alcohol  ob- 
tained from  the  washing  liquors  of  the  garancine  and  fleur  de 
garance  works  is  due  to  acetic  ether5  and  far  more  largely  to 
aldehyd.  The  impure  madder  spirit,  as  ordinarily  met  with  in 
trade,  is  an  excellent  source  from  which  to  prepare  and  obtain 
large  quantities  of  aldehyd  ammonia  by  the  following  method : 
From  20  to  30  litres  of  the  impure  spirit  are  placed  in  a  distill- 
ing apparatus  provided  with  a  long  metal  (copper)  worm,  and 
heated  to  60°  or  70°  C.,  while  at  the  same  time  a  rapid  current 
