86 MANUAL FOR SUGAR GROWERS. 



is led into a steam-jacket surrounding these vessels, 

 so that the juice is made hot as quickly as possible. 

 Cane-juice is always slightly acid, so, as soon as the 

 clarifier is about one-third or half full, a quantity of 

 slaked lime, made into a thin cream by mixing with 

 water, is thrown in, and the lime kept in slight 

 excess until the clarifier is nearly full. When the 

 clarifier is full the contents are vigorously stirred, 

 and the quantity of lime carefully adjusted. This 

 operation is known as tempering ; its effect is to 

 neutralise the acidity of the juice and to cause the 

 precipitation of the greater part of the impurities. 



Until recently this final adjustment of the quan- 

 tity of lime was left to the unaided judgment of the 

 workman in charge of the clarifiers. Consequently 

 there was great irregularity in the manner in which 

 the lime was used, sometimes an excessive, some- 

 times a deficient quantity being employed. As a rule 

 an insufficient amount was used. The sugar thus 

 produced of course varied considerably in quality. 

 After a number of experiments, the author, in an 

 article contributed to " Sugar," April, 1890, sug- 

 gested a method of working which is now very gen- 

 erally followed on estates making muscovado sugar, 

 with satisfactory results. The article is here repro- 

 duced : 



" When using lime for the purpose of neutralising 

 the juice of the sugar-cane and thus causing the pre- 

 cipitation of the albumen, some means of ascertain- 

 ing with precision when sufficient lime has been 

 added is highly desirable. 



" To meet this requirement Dr. John Shier, many 



