AtOcto°ber ^91™ ')  Monobromated  Camphor  in  Migraine  Tablets.  669 
amalgam,  an  effective  reagent  and  at  all  times  under  complete  con- 
trol of  the  operator. 
Experimental. 
The  tabulated  data  are  representative  of  numerous  results  ob- 
tained with  both  control  and  commercial  mixtures.  The  mono- 
bromated camphor  required  for  the  controls  was  prepared  by  recrys- 
tallization  of  a  well-known  foreign  brand  carrying  a  slight  excess 
of  halogen.  The  purified  product  melted  sharply  at  760  and  had  a 
bromine  content,  as  determined  by  Carius,  of  34.6  per  cent.  In 
general,  the  treatment  consisted  in  subjecting  the  powdered  sample 
in  alcoholic  solution  and  suspension  to  the  action  of  the  amalgam 
at  about  the  temperature  of  boiling  alcohol,  at  first  over  a  wire  gauze 
and  with  appropriate  reflux,  finally  on  the  steam  bath  to  practical 
exhaustion  of  the  amalgam,  and  with  no  attempt  at  condensation. 
The  amalgam  was  applied  in  a  strength  of  about  1  per  cent,  of 
sodium,  although  in  Expts.  5  to  8,  inclusive  (see  table),  a  product 
containing  only  0.6  per  cent,  of  sodium  was  employed.  After  quan- 
titative separation  of  the  liquid  from  the  mercury,  the  halogen  is 
precipitated  by  silver  nitrate  in  acidified  solution,  and  the  insoluble 
bromide  determined  in  the  usual  way.  In  general,  estimation  of  the 
bromine  via  Volhard  is  not  advocated,  on  account  of  possible  inter- 
ference from  accompanying  organic  substances. 
Experi- 
ment 
No. 
C10H15BrO 
Gram. 
PhNHAc 
Gram. 
Caffeine 
Gram. 
Starch 
Gram. 
NaHg 
Gram. 
AgBr 
Gram. 
Ci0H13BrO 
Calcd.  G. 
CinH15BrO 
Calcd. 
Per  Cent. 
I 
0.2000 
.... 
25 
O.I62I 
O.1994 
99-7 
2 
0.1000 
25 
0.08l0 
O.0996 
99-6 
3 
0.2000 
25 
O.1628 
0.2002 
100. 1 
4 
0.1000 
25 
O.0809 
0.0995 
99-5 
5 
0.2000 
25 
O.1619 
O.I99I 
99-6 
6 
0.2000 
20 
O.1617 
O.I989 
99-5 
7 
0.2000 
IS 
O.1596 
0.1963 
98.2 
8 
0.2000 
10 
O.I526 
0.1877 
93-8 
9 
0.2000 
IS 
6.1623 
O.I996 
99-8 
10 
0.2000 
10 
0.1622 
0.1995 
99-8 
11 
0.2000 
0.8000 
0.1000 
0.1000 
25 
O.1627 
0.2001 
100. 1 
12 
0.1000 
O.4OOO 
0.0500 
0.0500 
25 
0.08l2 
O.C998 
99.8 
13 
0.0Q72(?) 
O.3888 
0.0486 
■> 
25 
O.0762 
0.0937 
96.4(?) 
14 
0.0Q72(?) 
O.3888 
0.0486 
p 
25 
O.O768 
0.0945 
97-2(?) 
15 
0.1000 
O.4OOO 
0.0500 
0.2000 
25 
0.0812 
0.0999 
99.9 
16 
o.i296(?) 
O.1944 
0.0648 
~> 
25 
0.1052 
0.1294 
99-8(?) 
17 
O.I2Q6(?) 
O.1944 
0.0648 
-> 
25 
O.IO56 
0.1299 
100. 2(?) 
18 
0.1300 
0.2000 
0.0650 
0.1000 
25 
0.1059 
0.1303 
100.2 
19 
O.I2Q6(?) 
O.648O 
p 
25 
0.1068 
0.I3I4 
IOI.3(?) 
20 
O.I2Q6(?) 
O.648O 
p 
25 
O.IO65 
0.I3I0 
IOI.l(?) 
21 
0.1300 
O.65OO 
0.1000 
25 
6.IO56 
0.1299 
99.9 
