The Montgomery advertiser., 1903-03-14
TESTING SUGAR
LITTLE PHIAL OF SOLUTI0l
 TELLS FATE OF CARGO.
Use of the Polariscope In Making the Examinations-It Is Very Easy to Operate. But Difficult to
 Explain.

reckoned at approximately S,WO0OO tons, more than half of which is used in the United States. Of this vast amount prac- tially every pound has been tested before 1t goes to the sugar reflners, who event ually prepare 1t for domestic consump ton. This test determines the grades of the sugar and therefore the price which will be paid for 1t and is conducted in a chemical laboratory. But the curious thing is that the sugar is not tested by subjecting it to chemical agents, but merely by looking at solutions of Il through what at first sight appears very like a small telescope with an incan- descent light at one end.
 It Is only of late years that the i'm portancs of these tests has been fully realized. And of the technical schools in this country the Massachusetts Institute of Technology here in Boston has per haps the only school laboratory espe cially devoted to sugar analysis. Indeed the Question-which was discussed at the last International meeting of sugar eX perts in Paris-of bringing all such tests the world over, to uniform standard, has not yet been worked out to sat isfactory conclusion
 Grading sugar as 1t comes from the su- gar plantations to any one of the four Atlantic ports of entry-Boston, New York, Philadelphia or New Orleans-is a rapid and interesting process. When the sugar Is subject to duty the Gov ernment itself grades 1t and both con signor and consignee are usually con tent to accept the verdict of the Govern ment's experts But since a considerable amount of sugar now comes in without any duty at all the parties interested aTN iy,f thnf nnrtS yho nrlr t,N- dependently on either side, but whose tests must agree within three-tenths of l per cent. before they are accepted as final.
 How the Test is Made.
 Except for a certain amount of "open Gettle' sugar. so-cadled-the Drown" sugar of our manifestation Porto Rico and Cuba and another variety that comes from Java, our sugar now arrives in 100 or 300 pound bags Into each bag or hogshead from Porto Rico, or each crate from Java, long tin tube Is push ed diagonally from corner to corner. When this ''trier," as 1t Is called, Is withdrawn, its contents thus represent every part of the bag or crate. The next bag is sampled in the same way, and the next; and so on until every bag in the cargo has contributed and a big com poste sample of the whole consignment has been got together for the test. This is boxed and the box closed. sealed and labeled for the chemist
 Only small part of the contents of the box-thoroughy mixed of course, so as to be representative of the whole cargo is, however. used for the test, the re- mainder being sent to the refinery. This small sample Is very carefully trans formed into a solution which Is exam ined with the polariscope-a piece of la boratory apparatus extremely easy to operate and extremely difficult to ex- plain Comparatively few men who use the polariscope know the principles upon which 1t Is constructed. the main and im- portant fact being the action of a soiu- uon Of sugar on pOlarized ray of light "a beam of light, that is, that has been already passed through a peculiarly con structed prism of Iceland spar and has to quote the theoretical exclamation. been reduced to the condition of light vibrating in single plane of direction. " In the polariscope. before the sugar so- luton enters into the problem. a single ray or pencil of light passes through sev- eral prisms of different shapes and thick nesses. And by the mechanical manipu- lation of the prisms nearest the eyepiece the ray of light definitely records the changes which 1t undergoes in transmits sion.
 Now these changes are known and re- duced to a scale as are the further changes produced by the passage of light through solution of pure sugar After the instrument has been put in working order tube of standard length filled with a solution of the sugar to be tested Is introduced between the prisms Here 1t causes certain changes in the ray of light now passing through 1t and the op- orator must immediately change the po- sihon of the optical parts of the tnstru- ment In order to restore the original con- ditions on the field of vision. These changes are registered on the scale of the polariscope If the sugar. for exam pie is only 90 per cent. pure, that fact will be read on the dial the moment that the original appearance of the field of vision Is perfectly restored. If the sugar Is of standard purity the reading will be 100.
 Students Sent Abroad.
 Grading brown sugar. practically all of which nowadays goes directly to the re- iineries, Is of course only a small frac- ton of the work of sugar analysis-a de- partment of applied science that plays so large a part in modern commerce that hundreds of thousands of dollars may sometimes depend upon the exact knowl- edge of the sugar expert. Many of the