394  Commercial  Hypophosphite  Preparations.  {Ammi^r;^rm' 
produced  by  a  volumetric  method  instead  of  drying  at  ioo°  C.  and 
weighing.  All  results  are  expressed  in  terms  of  free  kypophospliorous 
acid,  since  the  basic  constituents  varied  in  the  several  preparations. 
From  2-5  grams  (in  the  first  determination  the  smaller  quantity  was 
taken,  and  if  the  preparation  was  found  to  be  weak,  the  larger  quan- 
tity was  taken  in  the  duplicate)  were  diluted  with  25  cc.  water,  1  cc. 
concentrated  hydrochloric  acid  and  25  cc.  of  a  cold  saturated 
solution  of  mercuric  chloride  added ;  after  heating  for  one  hour  in  a 
water-bath  at  ioo°  C,  the  separated  mercurous  chloride  was  filtered 
off,  thoroughly  washed  with  boiling  water,  allowed  to  drain,  dropped 
(filter  and  precipitate)  into  a  glass-stoppered  bottle  containing  10  cc. 
potassium  iodide  solution  (10  per  cent.)  and  5  cc.  dilute  sulphuric 
acid,  and  agitated  for  several  minutes;  tenth-normal  solution  of 
iodine  was  then  run  in  from  a  burette  until  the  liquid  in  the  bottle 
was  distinctly  brown  in  color  after  frequent  agitation  during  ten 
minutes ;  the  excess  of  iodine,  finally,  was  titrated  with  tenth-normal 
solution  of  sodium  thiosulphate.  By  subtracting  the  cc.  of  thiosul- 
phate  solution  from  the  cc.  of  iodine  solution  and  multiplying  the 
difference  in  cc.  by  0-00165  the  quantity  of  hypophosphorous  acid 
(free  and  combined)  present  in  the  weight  taken  will  be  obtained. 
The  tabular  statement  explains  itself : 
Specific 
gravity 
at  250  C. 
compared 
with  H20 
Hypophosphorous  acid  ; 
grains  per  fluid  ounce. 
Number 
Basic  constituents  present. 
of 
Q  =  Quinine. 
Sample. 
Calculated 
5  =  Strychnine. 
at  250  C. 
Found. 
from 
formula. 
1,  .  .  . 
i' 109 
0-366 
K,  Na,  Ca,  Fe,  Mn,  Q,  S 
2,  .  .  . 
1-299 
2-232 
K,  Ca,  Fe,  Mn,  Q,  S 
3,  •  ■  • 
1-284 
1-615 
same 
4,  .  .  . 
1-286 
1-207 
same 
5,  •  •  • 
1-291 
26-175 
26-520 
K,  Na,  Ca 
6,  .  .  . 
1*285 
24-313 
24-764 
same 
7,  .  .  . 
1-285 
24-564 
24-764 
same 
8,  .  .  . 
1-278 
24-710 
24-764 
same 
9,  .  .  . 
1-225 
31-478 
\  at  least 
K,  Na,  Ca,  Fe 
10,  .  .  . 
1-225 
31-071 
J  29-709 
same 
11,  .  .  . 
1-321 
22-020 
23-988 
K,  Na,  Ca,  Fe,  Mn,  O,  S 
12,  .  .  . 
i"337 
7  695 
Na,  Ca 
13,  •  •  • 
1-308 
12-618 
14*210 
Na,  Ca 
K,  Ca,  Fe,  Mn,  0,  S 
14,  .  .  . 
1-293 
2-893 
3*518 
15,  •  •  • 
1*290 
1 1 792 
10-584 
K,  Na,  Ca,  Fe,  Mn,  0,  S 
16,  .  .  . 
1  335 
19-461 
27-462 
K,  Na,  Ca 
Na,  Fe,  Mn,  0,  S 
17,  .  .  . 
1-297 
4-184 
9-935 
