AmjvS??ri J?arm* }  Carmine  Solution.  333 
it  may  be  inferred  that  commercial  carmine  is  mainly  a  tin  or  alumin- 
ium salt  of  an  acid  glucoside.  Further,  Dechan  found  that  all  alumin- 
ium or  tin  compounds  of  cochineal,  are  readily  soluble  in  dilute  am- 
monia, whereas  the  substances,  with  which  it  is  liable  to  be  adultera- 
ted, as,  for  example,  vermilion,  chrome  red,  starch,  uncombined  alum- 
ina, etc.,  are,  as  a  rule,  not  soluble  in  that  menstruum.  Liebermann 1 
found  that  pure  cochineal  carmine  is  not  entirely  soluble  in  alcohol  and 
water  ;  water  dissolves  it  sparingly,  alcohol  considerably.  Instead  of 
containing  only  traces  of  alumina  and  lime,  as  is  usually  supposed,  he 
found  as  high  as  8  per  cent. 
Some  months  ago,  I  commenced  a  series  of  experiments  upon  carmine 
and  its  solvents,  in  order  to  obtain,  if  possible,  some  practicable  pro- 
cess not  open  to  the  objections  previously  mentioned,  whereby  a  more 
stable,  concentrated  and  thoroughly  representative  product  could  be 
secured.  Suffice  it  to  say,  that  the  result  has  been  obtained  and  I 
present,  for  your  inspection,  a  sample  of  the  solution  made  over  two 
weeks  ago.    The  following  is  the  formula  : 
Carmine  (No.  40.)  giv. 
Water  of  ammonia,  f^iii- 
Glycerin,    f  ^iii. 
Water,  q.  s  \  ad  f^viii. 
Rub  the  carmine  into  a  fine  powder,  in  a  wedgwood  mortar,  make  a 
paste  with  and  dissolve  in  the  water  of  ammonia  and  then  add,  with 
constant  trituration,  the  glycerin.  Transfer  to  a  porcelain  capsule,  and 
heat  upon  a  water-bath,  until  the  liquid  is  entirely  destitute  of  ammo- 
niacal  odor,  cool  and  add  the  water.  The  entire  removal  of  the  am- 
monia gas,  requires  the  constant  stirring  of  the  liquid,  with  a  glass  rod, 
and  rather  lengthy  heating. 
The  finished  product  is  a  permanent  deep,  ruby-red  liquid,  per- 
fectly transparent,  destitute  of  ammoniacal  odor  and  mixes,  without 
turbidity,  with  all  aqueous  solutions.  It  should  develop  no  precipi- 
tate with  mercuric  chloride,  indicating  the  absence  of  free  ammonia • 
and  on  the  addition  of  AmHO  should  acquire  a  purplish  tinge.  It 
gives  the  true  carmine  color  to  solutions  without  exhibiting  the  pur- 
plish tinge  so  characteristic  of  alkaline  solutions.  30  to  60  drops  to 
a  pint  of  liquid  are  sufficient  to  color,  but  the  depth  of  color  may  be 
varied  to  suit  individual  tastes. 
iRundschau^o.  52.  p.  835;  A.  J.  P.  1886,  p.  102. 
