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1 Aprir, 1899.] QUEENSLAND AGRICULTURAL JOURNAL, 259 
Dairying. 
HOW TO TELL THE ACIDITY OF CREAM. 
Tir most satisfactory test for estimating the percentage of lactic acid in milk 
cream, skimmed milk, or whey, is known as the “ titration test,” and to apply 
it you must be free from colour-blindness. ‘The appliances needed are— 7 
One 50 c.c. burette, with glass tap 
One burette stand 
One 50 c.c. test measure 
One piece of glass rod 
A. glass tumbler or white teacup 
1 oz. aleoholic solution of phenol phthalein (1 in 500) 
}-gallon decinormal solution of caustic soda (4 grammes of pure caustic 
soda to 1 litre distilled water). 
You take a sample of milk or cream after it has stood at least half-an-hour, 
and is at or near the temperature of 60 degrees T'ahr. Shake the whole, to 
get a fair sample. Measure 50 c.c., and transfer to the tumbler or teacup. 
You should wash out the measure with water, so as to get all the milk or 
cream, and add that to the sample. Into this stir with the glass rod six drops 
of the indicator or phenol phthalein solution. Fill the burette up to 0 with 
the decinormal solution of alkali. ‘Turn the tap, and allow it to flow or trickle 
slowly on to the milk or cream containing the indicator. Keep up a brisk 
agitation with the glass rod. A bright pink colour develops as soon as the alkaline 
solution reaches the milk, but as rapidly disappears as the stirring is maintained. 
A point, however, is reached when the pink colour becomes permanent, and is 
observed throughout the milk or cream. Turn off the fluid quickly by means 
of the tap, and then read off the register of the burette the exact amount of 
alkaline-solution in cubic centremetres that is required to produce this effect. 
This permanent colour shows the exact point at which the alkali neutralises the 
lactic acid, and provides an essential factor in estimating the percentage of 
acidity. Each cubic centremetre of alkaline solution will neutralise ‘009 lactic 
acid, hence the formula for calculating the result. Say, for instance, that the 
milk sampled became neutral with 12 c.c. of solution, then— 
12 x :009 
x 100 = :216 per ec. lactic acid. 
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The principal point to keenly watch is the exact time at which the per- 
manent pink colour permeates the milk or cream, and to smartly shut off the 
alkaline solution. Dexterity in this direction means more accurate determina- 
tions, : 
DISCUSSION ON A DAIRYING PROBLEM. 
Tim Kansas State Board of Agriculture lately submitted a number of 
questions on dairying to several experts in America, with the view of gaining 
from their experience information on several points interesting to those who are 
engaged in the dairying industry. We append some of the answers to the 
following question :— 
__ What quantity of butter or cheese ought a cow to yield in a year to be 
tightly regarded as profitable for the dairy ?. 
Hoard.—Not less than 250 lb. of butter or 500 1b. of cheese. 
Haecker.—300 Ib. of butter and 500 lb. of cheese. 
Wallace.—At least 200 lb.; strive for 800 Ib. 
Wilson.—lt. depends upon locality and cost of feed; 200 1b. is tolerable. 
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