POLARISCOPE

an instrument now extensively employed for examining subjects in polarized light. One of the most important uses from the standpoint of food supplies, is to determine the amount of saccharose contained in sugars. The chief underlying principle is the fact that when a beam of polarized light is passed through a solution of pure sugar and water, it is rotated or twisted to a certain uniform extent toward the right. When any commercial sugar is similarly tested, its comparative purity is determined by its variance from, or agreement with, the standard of pure sugar.