50 PHILIPPINE AGRICULTURAL REVIEW. 



fication. In addition to this the sulphur acts to some extent di- 

 rectly as a clarifying agent, by precipitating some of the impur- 

 ities. It also acts as a bleaching agent by extracting the oxygen 

 from the impurities and lastly it acts as a disinfectant. It is 

 formed by burning crude sulphur in a stove made for that pur- 

 pose. S (sulphur) -+- O (oxygen heat) S(X (sulphur dioxide). 



Sometimes bombs filled with liquid sulphur dioxide are pur- 

 chased for this purpose. These are inconvenient to use, and this 

 method is ordinarily more expensive than the usual one of burn- 

 ing the sulphur and producing the gas directly at the factory. 



Sulphur dioxide is a heavy gas which is very readily absorbed 

 in water, and at a temperature of zero C. nearly 80 per cent by 

 volume of the gas will be taken up. 



At 40 C. only about 18 per cent by volume of the gas will 

 be absorbed. It may readily be seen that the percentage of 

 gas contained in the juice when saturated will be determined 

 by the temperature. 



The following equation expresses the absortion of sulphur 

 dioxide in water at ordinary temperature: 



S0 2 (sulphur dioxide) -f H,0 (water at low temperature) 

 "11,80;, (sulphurous acid). 



Another thing of very great importance is the cooling of the 

 gases to condense any water that may be present so that no 

 hot gas will reach the juice to be treated or combine with water 

 in the pipes. The equation represented when high temperatures 

 are used is as follows : 



S0 2 (sulphur dioxide) -fH,O (water) +0 (high temperature) 

 -H,SO 4 (sulphuric acid). 



This last-named acid is very corrosive and a powerful invest- 

 ing agent. It therefore has the property of rapidly destroying 

 sucrose, especially at a high temperature. 



In the burning of sulphur it is well that as thorough a com- 

 bination as possible be obtained, else there will be a loss of 

 sulphur, which will deposit in the tubes and choke them, and 

 more time will be required for the process. The fumes from 

 a well-regulated sulphur furnace should contain from 15 to 16 

 per cent sulphurous acid. The theoretical percentage obtainable 

 is about 21 per cent of the acid. 



Carbon dioxide. In recent years carbon dioxide gas has found 

 a very useful application in the cane-sugar factories, where a 

 good grade of plantation sugar is desired. 



Java factories have been the foremost in elaborating a system, 

 through their eminent technologists, so that today one may 

 find the bulk of the sugars they turn out from certain factories 



