332 
Thalleioquin  Reaction. 
Am.  Jour.  Pharm. 
May,  1921. 
ABSTRACTED  AND  REPRINTED 
ARTICLES 
THE  ORIGIN,  DEVELOPMENT  AND  VALUE  OF  THE 
THALLEIOQUIN  REACTION  * 
By  Wm.  Beamont  Hart,  F.  G.  C. 
An  investigation  as  to  the  analytical  value  of  the  thalleioquin 
reaction  was  carried  out  by  the  author  in  the  year  1909,  but  the  re- 
sults as  to  its  quantitative  value  were  of  such  a  negative  character 
that  they  were  not  considered  to  be  worthy  of  publication  at  the 
time;  in  view,  however,  of  later  published  work,  they  appear  to 
have  some  importance. 
The  earliest  published  record  of  the  green  coloration  produced 
by  the  addition  to  a  quinine  solution  of  chlorine  water  followed  by 
ammonia  is  made  by  H.  A.  Muson  (Phil.  Mag.,  1835,  158),  who  gave 
its  sensibility  as  1  in  8750.  In  Merck's  "Reagentzien  Verzeichnis" 
Manson's  reaction  for  morphine  and  quinine  is  mentioned,  but  from 
the  description  and  references  it  is  quite  evident  that  the  name 
"Manson"  is  a  misprint  for  "Muson."  Brandes  and  Leber,  1839, 
gave  the  -name  of  dalleiochin  or  thalleioquin  to  the  green  product, 
hence  the  name  of  the  reaction. 
The  reaction  has-been  developed  in  various  ways  too  numerous 
to  detail  here,  by  substitution  of  bromine  for  chlorine  or  by  different 
methods  of  liberating  halogen,  to  a  sensitiveness  of  1 :  20,000. 
Attempts  have  been  made  to  use  this  reaction  for  the  colorime- 
tric  determination  of  quinine,  using  varying  quantities  of  halogen  for 
•'quinine  molecule:  Trimble  2  used  38  atoms  of  chlorine;  Leger 3  used 
13  atoms  of  bromine,  and  states  that  the  method  is  useless;  Von- 
draseck,4  using  potassium  bromate  and  hydrochloric  acid,  assumed 
*Reprinted  from  the  Journ.  of  the  Soc.  of  Ckem.  Industry,  40:  7;  April, 
1921. 
^liickiger,  1872;  Vulpius,  Vitali,  1886;  Hyde,  1897,  etc. 
2  Allen,  "Comm.  Orig.  Anal.",  2nd  ed. ;  vol  3,  pt.  2,  pp.  401-402. 
3  Leger,  /.  Pharm.  Chim.,  1904,  281. 
4  Merck,  Ann.  Rep.,  1908,  275. 
