Am.  Jour.  Pharm.  \ 
March,  1889.  J 
Chemical  Notes. 
123 
Tinctura  Ferri  chloridi  was  procured  from  different  stores  by  Wal- 
ter Culin,  Ph.  G.  None  of  the  samples  gave  a  reaction  for  ferrous 
salt  with  potassium  ferricyanide ;  eight  of  the  samples  gave  reactions 
for  nitric  acid,  and  traces  ot  other  metals,  like  zinc,  were  detected  in 
the  same  number. 
The  effect  of  Sodium  chloride  upon  mercurous  chloride  was  studied 
by  John  L.  D.  Morison,  Ph.  G.,  in  the  following  manner :  Three 
beakers  were  placed  in  a  water-bath  for  five  or  six  hours  at  a  temper- 
ature of  40°  C. ;  each  beaker  contained  a  mixture  of  2  gm.  calomel, 
6  gm.  sodium  chloride  and  30  cc.  distilled  water ;  to  one  was  added 
2  cc.  hydrochloric  acid,  and  to  another  a  solution  of  pepsin  acidulated 
with  hydrochloric  acid.  The  light  was  carefully  excluded.  On  testing 
the  liquids  no  mercuric  chloride  was  found  ;  but  the  acidulated  pep- 
sin solution  contained  a  small  amount  of  calomel  (*?),  which  caused  a 
deposit  of  mercury  upon  bright  copper  foil,  and  this,  on  being  heated 
in  a  tube  yielded  a  sublimate  of  metallic  mercury  which,  with  a  frag- 
ment of  iodine,  formed  the  red  iodide. 
A  mixture  of  calomel  and  sodium  chloride  suspended  in  milk  was 
next  introduced,  by  means  of  a  rubber  tube,  directly  into  the  stom- 
ach of  a  dog.  After  one  hour  the  dog  was  killed  with  chloroform  ; 
the  stomach  with  contents  was  digested  with  ether,  the  ethereal  solu- 
tion distilled,  the  residue  freed  from  fat  by  petroleum  benzin,  and 
then  exhausted  with  boiling  distilled  water ;  this  solution  was  free 
from  mercury. 
Iodides  of  Mercury. — Robert  L  Eads,  Ph.  G.,  recommends  for  the 
preparation  of  the  red  iodide  to  use  the  mercuric  chloride  and  potas- 
sium iodide  in  exact  molecular  proportion,  whereby  loss  is  avoided. 
The  color  of  the  green  iodide  seems  to  be  affected,  aside  from  exposure 
to  light,  by  the  temperature  resulting  from  the  combination  of  the  two 
elements,  a  darker  color  with  a  brown  tint  being  produced  on  effect- 
ing the  combination  rapidly  with  the  development  of  heat. 
On  heating  solutions  of  mercuric  nitrate  with  excess  of  iodine  bright 
red  scales  are  obtained  after  cooling.  A  concentrated  solution  of  mer- 
curous nitrate  heated  with  excess  of  iodine  acicular  crystals  of  a  yel- 
lowish color  with  a  pink  tint  were  obtained  ;  dissolved  in  alcohol  and 
the  solution  evaporated  spontaneously,  scarlet  crystals  resulted.1 
1  A  number  of  compounds  of  mercuric  nitrate  with  iodide,  varying  in  color 
between  white  and  red,  have  been  described  by  Preuss,  Souville  and  others. — 
Editor. 
