344  Volumitric  Analysis,  {"""j^Iiris^so"™' 
5.  Volumetric  Solution  of  Oxalic  Acid. 
aH^O^  126. 
Oxalic  acid  being  bivalent,  the  normal  solution  is  made  by  dissolving 
-  =  63  grams  of  the  acid  in  a  sufficient  quantity  of  water  to  make 
the  solution  measure  one  liter. 
6.  Volumetric  Solution  of  Soda. 
NaHO  =  40. 
This  is  a  normal  solution,  and  contains  40  grams  of  sodic  hydrate  in 
one  liter  of  liquid. 
Might  not  the  process  of  volumetric  analysis  be  much  simplified,  and 
especially  in  view  of  the  abandonment  of  measures  of  capacity  by  the 
U.  S.  Pharmacopoeia,  would  it  not  be  more  in  accordance  with  the 
plan  of  the  work,  if  measures  of  capacity  were  abandoned  here  also  ? 
True,  the  process  would  no  longer  be  volumetric,  but  the  leading  prin- 
ciple upon  which  the  system  is  based  would  still  remain. 
It  is  proposed,  then,  that  all  test  solutions  should  be  made  gravimet- 
ric instead  of  volumetric  ;  that  is  to  say,  repeating,  for  example,  the 
process  of  testing  the  amount  of  silver  in  a  Bland  dollar,  the  standard 
solution  of  chloride  of  sodium  would  be  prepared  by  dissolving  58*5 
grains  of  chloride  of  sodium  in  distilled  water,  and  diluting  the  solution 
until  it  weighed  1,000  grains,  instead  of  measuring  1,000  grain-mea- 
sures, as  before.  In  this  case  every  grain  (weight)  of  this  solution, 
upon  being  added  to  the  silver  solution,  will  combine  with  O'loS  grain 
of  pure  silver,  and  no  further  observation  is  necessary  than  to  note  how 
many  grains  of  the  salt  solution  have  been  used.  This  plan  would  do 
away  with  all  apparatus  ;  the  only  instruments  necessary  to  carry  it  out 
would  be  flasks  or  appropriate  vessels  in  which  to  weigh  the  solutions, 
and  an  accurate  set  of  scales  and  weights  to  weigh  them. 
Variations  in  temperature  would  not  affect  the  results,  and  inasmuch 
as  weighing  can  be  done  with  more  exactness  than  measuring,  greater 
accuracy  would  be  obtained. 
This  plan  would  be  equally  satisfactory  with  any  system  of  weights, 
whether  the  British  system  or  the  metric  system,  or  simply  parts  by 
weight  were  used. 
This  same  principle  applied  to  all  the  test  solutions  would,  in  my 
•  opinion,  render  the  operation  more  easy  of  execution,  retaining  all  the 
advantages  and  discarding  some  disadvantages  of  the  present  system. 
The  principal  facts  herewith  presented  have  been  derived  from 
"The  Systematic  Handbook  of  Volumetric  Analysis,"  by  Francis 
Sutton,  F.  C.  S,,  published  London,  1876,  to  which  the  reader  is 
referred  for  further  information  on  the  subject. 
