I24 
Estimation  of  Caseine. 
f  Am.  Jour.  Pharm. 
\      March.  1906. 
A  b 
2S 
*0 
Q'8 
IO*2 
^  a 
20 
12*0 
8'o 
5  b 
20 
12*2 
7*8 
5  c 
IO 
i6*o 
4'o 
5  d 
IO 
i6*o 
4'o 
6  a 
20 
I2'0 
8o 
6  b 
20 
n-8 
8'2 
6  c 
IO 
i6'o 
A'O 
6  d 
IO 
i6'o 
d'O 
7  a 
XO 
o 
8-o 
12  "O 
7  b 
o 
8-o 
I2'0 
7  c 
20 
12*0 
8-o 
7  d 
20 
I2'0 
8-o 
7  e 
IO 
i6*o 
A'O 
7  f 
IO 
l6'2 
^•8 
8  a 
t; 
o 
i8*o 
2*0 
8  b 
5 
i8*o 
2*0 
8  c 
IO 
i6*o 
4*o 
8d 
IO 
i6*o 
4*o 
8  e 
20 
I2'0 
8'o 
8  f 
20 
12*0 
8*o 
q  a 
20 
n-8 
8*2 
9  b 
20 
n-8 
8'2 
Q  C 
IO 
4*2 
q  d 
IO 
T  C  *n 
4  1 
io  a 
5 
i8'o 
2  0 
io  b 
5 
i8-o 
2'0 
IO  c 
IO 
i6-2 
3'8 
io  d 
IO 
i6'o 
4*o 
io  e 
20 
ii -8 
8-2 
IO  f 
20 
I2-0 
8-o 
As  shown  by  above  figures  the  results  are  definite  as  to  caseine 
content.  It  will  be  observed  that  the  amount  of  ferric  alum  used 
for  5,  io,  20  or  30  c.c.  is  in  direct  proportion  to  these  amounts,  and 
that  the  variation  on  different  samples  of  milk  is  no  greater  than 
would  be  expected  of  its  varying  caseine  content. 
The  feasibility  of  the  process  depends  on  whether  the  other  con- 
stituents of  the  milk,  such  as  sugar  and  fat,  enter  into  the  reaction 
with  ferric  alum.  The  following  experiments  seem  to  show  that 
such  fears  are  groundless. 
Filtrate  from  10  c.c.  milk,  plus  20  c.c.  ferric  alum  solution,  required 
16  2  c.c.  decinormal  thiosulphate  solution.  Filtrate  from  10  c.c. 
same  milk,  plus  0*4  grammes  milk-sugar  (same  amount  as  in  original 
milk),  required  16-2  c.c.  decinormal  thiosulphate  solution. 
