*4 
Solution  of  Dialyzed  Iron. 
{  Am.  Jour.  Pharm. 
1       Jan.,  1878. 
A.  Ten  centigrams  of  arsenious  acid  was  dissolved  in  25  cubic  cen- 
timeters of  distilled  water,  and  tested  for  arsenic,  abundant  evidence 
of  which  was  readily  shown.  To  this  solution  5  cubic  centimeters  of 
a  5  per  cent,  solution  of  dialyzed  iron  was  added,  and  the  whole 
diluted  with  distilled  water  to  the  measure  of  100  cubic  centimeters, 
and  filtered.  No  apparent  change  was  effected,  the  filtrate  giving  abun- 
dant evidence  of  the  presence  of  arsenic.  The  experiment  was  again 
performed,  substituting  ordinary  water,  with  like  result. 
B.  A  like  quantity  of  arsenious  acid  was  dissolved  in  the  same 
amount  of  distilled  water  as  before,  with  the  addition  of  a  few  drops  of 
hydrochloric  acid,  and  to  this  solution  5  cubic  centimeters  of  solution 
of  dialyzed  iron  was  added,  and  the  filtrate  tested  as  before,  with  like 
result.  The  experiment  was  then  varied  by  the  substitution  of  ordi- 
nary water  and  the  addition  of,  first,  1  cubic  centimeter  of  the  iron  solu- 
tion, and  afterward  the  addition  of  25  cubic  centimeters,  and  dilution  of 
the  whole  with  water  to  the  measure  of  100  cubic  centimeters  ;  the 
various  testings  were  without  change,  the  abundance  of  arsenic  being 
readily  shown. 
C.  A  third  experiment  was  now  instituted.  Ten  centigrams  of 
arsenious  acid  being  taken  as  before,  and  dissolved  in  the  same  quantity 
of  water,  this  was  added  to  1,000  cubic  centimeters  of  a  solution  made 
to  represent  the  gastric  secretion  of  the  human  stomach,  and  composed 
as  follows  : 
Water,  ....  994*40  Chloride  calcium,  .  .  0*06 
Pepsin,    ....  3-19      Hydrochloric  acid,  .       .       .    0  20 
Chloride  sodium,         .       .       1-46      Phosphate  magnesium,        .  0*12 
Chloride  potassium,        .       .    0  55 
The  quantity  of  this  fluid  taken  (1,000  cubic  centimeters)  was 
believed  to  represent  about  the  normal  quantity  of  gastric  juice  present 
in  the  human  stomach  during  digestion,  or  that  would  be  induced  upon 
the  ingestion  of  a  quantity  of  arsenic.  Immediately  after  the  addition 
of  the  iron  solution,  the  whole  was  transferred  to  a  filter,  and  the 
colorless  filtrate  tested  by  Fleitmann's  and  Marsh's  test.  No  evidence 
of  the  presence  of  arsenic  could  be  discovered,  and  the  experiment  was 
repeated  with  like  result. 
The  experiment  was  then  varied  by  dissolving  50  centigrams  of 
arsenious  acid  in  the  above  quantity  of  artificial  gastric  fluid,  and  allow- 
ing the  whole  to  remain  at  a  temperature  of  38°C.  (ioo°F.)  for  two 
