4 BULLETIN 1114, U. S. DEPARTMENT OF AGRICULTURE. 
Table 1. — The hypochlorite test in tabular form. 1 
Test. 
Parts of available chlorin with different color reactions. 
1:1,000 
1 : 2,500 
1 : 5,000 
1 : 10,000 
1 : 25,000 ! 1 : 50,000 
Take 5 c.c. milk 
Reddish 
color. 
Yellowish 
brown. 
Yellowish 
Slightly 
discolored. 
Deep yellow. 
Deep yellow. 
Deep yellow. 
Blue purple. 
! 
tion. Milk appears. 
Add 4 c.c. HC1. Curd 
fades. 
::::::: :::::;:::: 
appears. 
After heating at 85° G. 
and cooling, the curd 
and liquid below ap- 
pear. 
Add 0.5 c.c. starch solu- 
tion. Liquid below 
curd appears. 
brown. 
Yellowish 
brown. 
Blue purple . 
Yellow 
Blue purple. 
Yellow... 
Dark - red 
purple. 
Pale yellow . 
Red purple. 
Yellowish. 
Pale-red 
purple. 
1 The test for chloramins is approximately the same. 
REACTION IN PASTEURIZED MILK. 
If hypochlorite solution is added to milk in different proportions 
and the milk is then pasteurized at 145° F. for 30 minutes, the 
results obtained by the above test after the milk has been kept in 
the ice box for 24 hours are approximately the same as with raw 
milk. 
REACTION IN CREAM. 
Hypochlorites or chloramins added to 20 per cent cream in dif- 
ferent proportions give results approximately the same as with 
milk. 
With 1 part of chlorin in 2,500 parts of cream, the cream turns 
yellow on adding the iodid solution. At 1:5,000 dilution and 
above, no change is apparent after adding hydrochloric acid to the 
cream -iodid mixture, and it is necessary to heat the cream in order 
to bring about the reaction. At 1 : 25.000 dilution both the curd 
and the liquid below are a pale yellow, while at 1:50,000 dilution 
the curd is a little more yellow than the control and the liquid below 
is the same as in the control. After adding starch to the liquid 
below the curd, it acquires a pale-red purple color with hypo- 
chlorites at 1 : 50,000 dilution, while with chloramins it remains 
the same as the control at this dilution. At 1 : 25,000 dilution the 
reaction is distinct with chloramins. 
After heating the cream- iodid-hydrochloric-acid mixture, the pres- 
ence of small amounts of chlorin must be judged by the color of 
the liquid below the curd, because the curd, owing to the presence of 
the fat globules, has a pale-yellowish color. The yellow color of the 
curd becomes more marked as the amount of chlorin present in- 
creases, while the liquid below the curd has the same color as in milk. 
The above test applies equally well after the milk or cream has 
been kept in the ice box for 48 hours. 
