Am.  Jour.  Pharm. ) 
January,  1911.  j 
Note  on  Lactic  Acid. 
17 
TABLE  I.  —  Continued. 
No.  of 
sample. 
No.  of 
procedure 
Amount  of 
lactic  acid  so- 
lution taken. 3 
(c.c.) 
N/io  NaOH 
added  before 
titration, 
(c.c.) 
N/io  NaOH 
required, 
(c.c.) 
Lactic  acid 
strength  of 
sample. 
5 
I 
20 
0 
18.70 
71.90 
5 
2 
20 
0 
21.70 
83-44 
5 
3 
20 
0 
22.55 
86.71 
5 
4 
20 
40 
23-15 
89.01 
c 
5 
5 
40 
23.20 
09.21 
6 
I 
20 
0 
18.65 
71-75 
6 
2 
20 
0 
21.60 
83.09 
6 
3 
20 
0 
22.60 
86.94 
6 
4 
20 
40 
23.20 
89.25 
0 
5 
20 
40 
23-25 
«9.44 
7 
I 
20 
0 
18.70 
72.71 
7 
2 
20 
0 
21.50 
83-59 
7 
3 
20 
0 
22.25 
86.51 
7 
4 
20 
40 
23.10 
89.82 
7 
5 
40 
23.10 
09.02 
8 
I 
20 
0 
18.35 
71-25 
8 
2 
20 
0 
22.45 
87.17 
8 
3 
20 
0 
23-75 
92.22 
8 
4 
20 
40 
24.30 
94-35 
8 
3 
20 
40 
24-35 
.  94-55 
TABLE  II. 
Showing  the  Results  Obtained 
on  Titrating 
Lactic  Acid  with  Nor- 
mal  Alkali  by  Various  Procedures. 
No.  of 
experiment 
No.  of 
procedure^ 
Amount  of 
sample  taken. 
(Gm.) 
N/i  NaOH 
added  before 
titration. 5 
(c.c.) 
N/i  NaOH 
required, 
(cc.) 
Lactic  acid 
strength  of 
sample. 
(Per  cent.) 
I 
I 
2.4280 
0 
19.50 
72.28 
2 
2 
2.4280 
0 
23.20 
85.99 
3 
3 
2.4280 
0 
23-35 
86.55 
4 
4 
2.4143 
50 
23-50 
87.60 
5 
5 
2.3649 
50 
23.12 
87:99 
6 
6 
2.3899 
50 
23.27 
87.63 
*  Procedure  No.  6  differed  from  No.  4  only  in  that  the  alkaline  mixture 
was  allowed  to  stand  fifteen  minutes  instead  of  thirty,  before  titrating  the 
excess  alkali. 
°  Where  no  alkali  was  added  before  the  titration  an  equal  volume  of 
water  was  added  instead. 
