THE PREPARATION AND USE OF LIME AS A NEUTRALIZER 195 



The common practice in creamery work is to measure the 

 lime mixture, in adding it to the cream, instead of weighing it. In 

 case this is done the mixture should be made up so that there 

 will be 12.5 pounds of quicklime in 10 gallons of the mix, that is, 

 this quantity of lime should be mixed with about 8 gallons of hot 

 water and then brought up to 10 gallons by adding sufficient hot 

 water. This water to be added should be heated in an open vessel 

 so as to drive off any carbonic acid gas there may be in it, and 

 should not be added directly from a hose or tap. 



In 10 gallons of the mixture there are 12.5 pounds lime. 



12 t\ 



In i quart of the mixture there is - = .3125 pound lime. 



40 



We have already shown that .3111 pound quicklime will 

 reduce the acidity of 1000 pounds cream .1 per cent. Hence, i 

 quart of the lime mixture, which contains .3125 pound quicklime, 



will reduce the acidity of 1000 pounds cream- '- - = .1004 



.3111 



per cent = .1 per cent practically. Or, i pint of the lime mixture 

 will reduce the acidity of 1000 pounds cream .05 per cent. It 

 is upon these figures that the table on page 196 is based. 



How many pints of lime mixture will it take to reduce the 

 acidity of 3400 pounds of cream from .70 to .25 per cent? In the 

 column under .70 and opposite 3400, this is given as 30.5 pints. 

 The same quantity of lime mixture would be used for all acidities 

 nearer to .70 per cent than either .65 per cent or .75 per cent. 

 This principle applies all through the table. 



Note the simple numbers opposite 1000 pounds of cream. 

 The quantity of mixture required for any weight of cream can be 

 quickly determined by multiplying the weight of cream by the 

 amount of mixture required to reduce the acidity of 1000 pounds 

 of cream to .25 per cent and dividing by 1000 (or pointing off 

 three decimal places) . Example : 



How many pints of lime mixture will be required to reduce the 

 acidity of 6300 pounds of cream from .80 per cent to .25 per cent? 



1000 pounds of cream require 1 1 pints of mixture. 



6300 pounds of cream require n X 6.300 = 69.3 =69.5 pints of 

 mixture. 



