88 MARKET DAIRYING 
PRECAUTIONS IN MAKING ACID TESTS. 
1. Always thoroughly mix the cream or milk before 
taking a sample for a test. : 
2. Prepare the tablet solution and dilute the cream 
with water as nearly neutral as possible. Soft water is 
better than hard. 
3. Keep the tablets dry and well bottled. 
4. Keep the Manns neutralizer and the Farrington 
tablet solution carefully stoppered with a rubber stopper, 
as exposure to the air will weaken the solutions by absorb- 
ing carbonic acid. 
5. With the Farrington tablets it is best to prepare 
a new solution every day. 
6. Make the tests where there is plenty of light so 
that the first appearance of a permanent pink color can 
readily be noticed. 
RELATION OF RICHNESS AND ACIDITY IN CREAM. 
In practice we find that the ripening is slower in rich 
than in poor cream. The reason for this is that the acid 
develops in the milk serum, which really should be used 
as the basis in measuring the degree of acidity, if this 
were possible. 
In a cream testing 25% we find that more acid must 
be developed to get the desired effects in cream ripening 
than is necessary in a 35% cream. This is so because in 
the 25 % cream we have the acid distributed through 75% 
milk serum, while in the 35% cream it is distributed 
through only 65% milk serum. 
If both the above creams show an acidity of .5%, this 
means that in the poor cream the .5 pound of acid is 
distributed through 75 pounds of serum, while in the rich 
