88 MANUAL FOR SUGAR GROWERS, 



one of them. If sufficient lime lias been used tlie 

 addition of tlie phenol-plitlialein solution will cause 

 a slight change of colour to pink ; if the quantity of 

 lime is insufficient there will be no change of colour ; 

 in this case a little more lime must be put into the 

 clarifier, care being taken that it is well mixed, and 

 a fresh portion of the juice put into the tubes and 

 tested as before ; and this must be repeated until a 

 very faint pink coloration is obtained. If too much 

 lime has been used the addition of the phenol-phtha- 

 lein solution will cause a strong pink to red colour- 

 ation, and in this case the excess of lime must be 

 corrected by adding a sufficiency of fresh juice until, 

 on applying the test, only a faint change of colour' is 

 observed. 



" This method of working has been emploj^ed 

 successfully on several sugar estates, resulting in 

 much more uniform work than has hitherto been 

 obtained ; it is also found that juice thus tempered 

 gives very little scum in the subsequent process of 

 evaporation, inversion is checked, and consequently 

 the yield of molasses is lessened. 



" To prepare the test solution, about ten grains of 

 phenol-phthalein are dissolved in about half a pint 

 of alcohol, white rum, or high-Avines. The alcohol- 

 being frequently slightly acid, the acidity is neutral- 

 ized by adding lime-water drop by drop to the solu- 

 tion until a faint pink colour makes its appearance 

 and remains permanent. This faint colour is next 

 destroyed by adding a small quantity of spirit until 

 the colour just disappears ; with good spirit the use 

 of lime-water to correct acidity is imnecessary." 



