Carmine. 
Am.  Jour.  Pharm 
Jan.,  1886. 
CARMINE. 
By  M.  Dechan,  F.C.S. 
(Read  before  the  British  Pharmaceutical  Conference.) 
The  discovery  of  carmine  is  generally  supposed  to  Have  been  acci- 
dentally made  by  a  Franciscan  monk  while  engaged  in  the  preparation 
of  some  medicament  from  the  body  of  the  cochineal  insect,  which  was 
at  that  time  (about  the  sixteenth  century)  and  is  even  now  considered 
by  many  to  possess  valuable  medicinal  properties. 
Preparation  of  Carmine. — In  the  preparation  of  commercial  carmine 
no  attempt  is  made  to  produce  a  compound  possessing  a  constant  chem- 
ical composition,  the  prime  object  of  the  manufacturer  being  to  obtain 
a  substance  having  certain  well-marked  physical  properties.  I  have 
selected  the  following  methods  from  those  given  in  standard  works, 
for  the  purpose  of  showing  that  we  may  expect  to  find  considerable 
diversity  in  the  composition  and  general  characters  of  this  substance. 
China  or  Spirit  Process. — One  pound  of  cochineal  is  boiled  for 
fifteen  minutes  in  3  gallons  of  water,  then  1  drachm  of  powdered  alum 
is  added,  and  the  whole  boiled  for  five  or  six  minutes  longer.  When 
the  liquid  has  become  cold,  the  clear  portion  is  decanted,  and  again 
heated.  Tin  spirits  is  now  cautiously  dropped  in  until  all  the  carmine 
is  precipitated;  it  is  then  collected,  drained  and  dried. 
French  Process. — The  quantity  of  cochineal  and  water  is  the  same  as 
in  the  preceding  method,  and  after  boiling  fifteen  minutes  1  ounce  of 
cream  of  tartar  in  powder  is  added,  and  the  boiling  further  continued 
for  ten  minutes,  when  ounces  of  alum  are  thrown  in.  After  two 
minutes'  boiling  the  heat  is  withdrawn,  and  in  five  or  six  minutes 
more  the  clear  portion  is  decanted  into  porcelain  vessels,  which  are  set 
aside  until  the  carmine  falls  down. 
English  Process. — One  pound  cochineal  and  J  ounce  carbonate  of 
potash  are  boiled  for  fifteen  minutes  in  seven  gallons  of  water.  The 
heat  having  been  withdrawn,  1  ounce  of  powdered  alum  is  added; 
the  whole  is  well  agitated  and  allowed  to  settle  for  about  fifteen  min- 
utes. The  clear  liquid  is  next  decanted  into  a  clean  copper,  and  J 
ounce  isinglass  having  been  added  heat  is  applied  until  coagulum  forms 
on  the  surface ;  it  is  then  stirred  briskly  and  allowed  to  settle. 
Madame  Genette's  Process. — This  process  is  said  to  yield  carmine  of 
extraordinary  lustre  and  beauty.  The  carmine  is  said  to  be  pre- 
pared by  this  method  without  the  use  of  either  alum  or  tin  spirits,  but 
I  have  utterly  failed  to  prepare  carmine  by  it,  although  the  specified 
