Am.  Jour.  Pharm. 
Jan.,  1886. 
Carmine. 
33 
percentage  of  matter  insoluble  in  ammonia  calculated.  The  residue 
on  the  filter  was  now  washed  with  dilute  hydrochloric  acid  and  dis- 
tilled water,  again  dried  and  weighed;  in  the  absence  of  chrome  red, 
the  loss  in  weight  was  calculated  as  uncombined  alumina  and  lime. 
The  substance  left  on  the  filter,  after  washing  with  hydrochloric  acid 
was  ignited  and  the  loss  calculated  as  albuminous  and  starchy  matters. 
If  vermilion  was  present  the  mercury  was  determined  by  a  combustion 
analysis,  and  the  proportion  of  sulphide  to  the  other  substances  calcu- 
lated. In  all  cases  the  ash  of  the  whole  substance  was  determined, 
as  well  as  the  ash  of  the  insoluble  residue. 
The  following  simple  method  was  adopted  for  detecting  the  presence 
of  aniline  carmine  in  the  ammoniacal  filtrate.  Small  pieces  of  clean 
white  woolen  cloth  were  boiled  for  thirty  minutes  in  the  solution,  and 
the  tint  of  color  produced  carefully  examined.  From  a  series  of  com- 
parative experiments  it  Avas  found  that  1  per  cent,  of  aniline  carmine 
mixed  with  cochineal  carmine  manifests  its  presence  quite  distinctly, 
the  color  assuming  a  red-orange  tint,  whereas  with  pure  cochineal  car- 
mine it  is  of  a  reddish-purple  shade.  [None  of  the  samples  contained 
any  aniline  carmine ;  and  it  is  well  to  know  that  this  substance  need  not 
be  looked  for  if  oxide  of  tin  is  absent  in  the  ash  of  the  whole  substance. 
That  the  carmine  of  commerce,  is  not  above  suspicion  will  be  seen 
from  the  appended  table  in  which  are  summarized  the  results  of  the 
examination  often  samples  obtained  from  different  parts  of  the  coun- 
try. In  one  case  only  was  the  purchase  accompanied  by  any  qualifi- 
cation as  to  purity,  the  seller  of  ~No.  7  stating  that  the  material  sup- 
plied was  only  of  second  rate  quality. 
The  alumina  and  lime  given  as  combined  in  the  table  is  that  which 
has  entered  into  combination  with  the  coloring-matter  of  the  cochineal. 
This  combination  must  not  be  considered  as  purely  chemical,  as  it 
partakes  of  a  physico-chemical  nature;  hence  an  exact  numerical  pro- 
portion must  not  be  looked  for  between  the  combined  alumina,  lime, 
and  coloring-matter. 
No.  1. 
No.  2. 
No.  3. 
No.  4. 
No.  5. 
No.  6. 
No.  7. 
No.  8. 
No.  9. 
No.10. 
Carmine  (coloring-matter)  
Combined  alumina  and  lime 
Matter  insoluble)  ^ 
m  ammonia.  /Vermillon 
6-1 
8-0 
1-  8 
2-  0 
221 
69-2 
9-8 
25 
24 
161 
ioo-o 
341 
11-4 
18-5 
34-0 
2-0 
65  7 
12-0 
00 
Tr. 
22-3 
608 
9-0 
9-8 
02 
20-2 
69-5 
7-0 
o-o 
Tr. 
23-5 
26-1 
04 
o-o 
14-6 
50-4 
8-5 
72  0 
8-1 
8-0 
1-9 
10-0 
18  4 
4-4 
52  4 
36 
2T2 
67-5 
10  0 
9-5 
Tr. 
130 
100-0 
ioo-o 
ioo-o 
ioo-o 
oo-o 
ioo-o 
ioo-o 
ioo-o 
ioo-o 
—Phar.  Jour,  and  Trans.,  December  12,  1885. 
