NORTHERN SUGAR INDUSTRY. 



103 



Two kinds of polariscope are in common use : 



(1) Those which use ordinary light, like that of a lamp or the sun. 



(2) Those which use light of one color (monochromatic light). 



The first kind is more expensive and more convenient as regards the 

 source of light ; the second, cheaper and more accurate. 



The chief objection to the use of a polariscope in small sugar works 

 is [a) the cost and (b) the absence of any one skilled in its use. 



Polariscopes of the finest construction and large size cost several 

 hundred dollars, while even those less carefully constructed and smaller 

 in size cannot be had for much less than $100. 



• The figure (12) contains a view of the apparatus necessary for mak- 

 ing an optical analysis of the juices of the cane. 



