"""•A-irxs^sor'""'}  The  Thalleioquin  Test.  389 
It  will  be  seen,  by  looking  over  these  tables,  that  as  the  amount  of 
hydrochloric  acid  was  increased  the  ammonia  was  proportionately 
increased  also  ;  for  instance,  fresh  chlorine  water  without  acid  required 
I  drop  solution  ammonia  to  produce  the  emerald-green  color  and  this 
Amount  of  Solution  of  Ammonia  required.  ^ 
Old  chlorine    5  per  cent.    10  per  cent.  15  per  cent.    25  per  cent.         50  per  cent, 
water.  acid.  acid.  acid.  acid.  acid. 
Quinia  solution,  2  drops  2  drops  5  drops  3  drops  5  drops  scarcely  shows 
Quinidia    "  «*  "  "  "  "  precipitate 
seems  to  prove  that  after  a  certain  amount  of  acid  has  been  neutralized 
the  excess  of  chlorine  bleaches  out  the  color,  forming  a  yellow  solu- 
tion, which  turns  to  an  amber-brown  color  if  the  acid  be  not  present 
in  too  large  a  quantity. 
As  a  matter  of  interest  the  bromine  water  test  was  tried,  having 
been  recommended  as  being  more  delicate  than  chlorine  water.  A 
saturated  solution  of  bromine  was  made  by  dissolving  12  drops  of  bro- 
mine in  I  fluidounce  of  distilled  water.  It  was  found  by  experiment 
that  100  grains  of  sulphate  of  quinia  or  quinidia  solution  required  but 
5  drops  of  bromine  water  and  i  drop  solution  ammonia  to  produce  a 
clear  emerald-green  color. 
To  sum  up  these  experiments  it  may  be  stated,  ist.  That  the  chlo- 
rine water  for  performing  this  test  should  be  freshly  prepared  is  not 
absolutely  necessary,  provided  it  is  preserved  in  amber-colored  glass 
bottles,  tightly  corked,  and  kept  in  a  dark  place.  Chlorine  water  which 
had  been  kept  in  this  manner  over  a  year  gave  test  color  well,  as  seen 
in  tables  C  and  D.  2d.  That  hydrochloric  acid,  when  added  to  fresh 
chlorine  water,  in  quantities  not  exceeding  25  per  cent.,  does  not  pre- 
vent its  giving  the  test  color,  but  will  require  a  proportionately  large 
amount  of  ammonia  to  neutralize  the  acid  so  added.  3d.  That  when 
hydrochloric  acid  is  present  in  old  chlorine  water  (the  result  of  decom- 
position)  it  is  due  to  the  loss  of  chlorine  so  incurred,  that  the  solution 
loses  its  value  as  a  test  liquid.  4th.  It  has  been  shown  that  bromine 
water  is  about  four  times  more  delicate  than  chlorine  water,  requiring 
but  one-fifth  to  one-twelfth  as  much  to  produce  the  same  results.  5th, 
On  account  of  the  simplicity  and  ease  with  which  bromine  water  can 
be  made,  it  is  very  much  to  be  preferred  as  a  means  of  performing  the 
thalleioquin  test. 
