58o 
Pharmacopoeial  Standard  for 
/  Am.  Jour.  Pharm. 
December,  19 17. 
Table  I. 
Results  by  Silver  Chloride  and  by  Author's  Method. 
On  Basis  of  1  Cc.  Na2S03  =  0.0038204  Gm.  CI. 
Material  Analyzed. 
No 
Per  Cent.  Chlorine. 
Calc.      By  AgCl. 
By  Is 
Sodium  chloride  (NaCl) 
Potassium  chloride  (KC1) 
BaCl2.2H20  
CUCI2.2H2O  
CuCl2.2KCl.2H2O  
Dry  cell  mixes  
Chloride  liquors  (containing  Mn,  Zn,  NH4 
and  Ca) 
Rare  earth  fluorides  
Manganese  ores  
60.66 
47 
56 
60.66 
47-52 
5.78 
5-40 
17-75 
13.48 
10.92 
o  10 
0.23 
60.74 
60.51 
60.91 
70.67 
60.73 
60.87 
60.81 
47-49 
47-49 
47-49 
47.61 
47.61 
47-51 
47-54J 
28.95 
41-59 
44.67 
5-74 
5-49 
17-65 
13.04 
11.06 
0.13 
0.24 
0.001 
0.005 
0.002 
-Av.  60.75 
Av.  47.53 
In  Table  I  are  tabulated  the  results  of  some  determinations  of 
chlorine  in  chlorides  and  products  containing  chlorides  by  the  above 
method.  If  values  in  Table  I  for  sodium  chloride,  which,  by  precipi- 
tation, gave  60.00  per  cent.  CI  (the  theoretical  content),'  are  used  for 
the  standardization  of  the  sodium  thiosulphate  solution,  the  mean 
value  for  i  Cc.  Na2S203  gives  0.003815  Gm.  CI.  and  if  this  value  is 
used  to  calculate  CI  in  the  potassium  chloride  (Table  I)  the  follow- 
ing* figures  are  obtained : 
Potassium  chloride  No.  11234567  Av. 
Per  cent,  chlorine    47-42   47.41    47.41    47.53    47.54    47.44    47.41  47.46 
The  figures  given  in  this  paper  were  obtained  under  the  ordinary 
technical  analytical  laboratory  conditions  and  no  claims  of  extreme 
precautions  and  care  are  made  by  the  author,  but  from  the  results 
given  it  is  clear  that  the  errors  in  the  determination  of  chlorine  in 
