Report of Society's Meetings. 195 



Society to establish a class of licensed Polarizers with as much dis- 

 favour as would a Surgeon, for instance, the establishing of a class of 

 "bone-setters," or as the members of any other profession would the 

 licensing of any similar kind of interlopers. 



As a Government servant I am of opinion that the matter is not of 

 sufficient importance to be made the subject of legislation. From an 

 experience of several years, I estimate that the number of samples 

 required to be polarized annually for business purposes in the colony 

 does not exceed one thousand, and it seems hardly worth while to 

 create a class of specialists to share the thousand dollars or so that 

 would result from the performance of the work at the reduced fee. 



Granting, however, that the matter is worth legislating upon, the 

 Government would have, I think, great difficulty in giving effecl; to the 

 Commercial Committee's resolution. Many persons are unable to read 

 a polariscope corre&ly owing to defective sight, therefore, before 

 granting a licence it would be necessary to ascertain th?t the applicant 

 was fit to do the work, and examiners would have to be appointed for 

 that purpose. But a professional polarizer should not only be able to 

 do the necessary manipulations, and read his instrument, but should be 

 able to assure himself that his readings are right. Few polariscopes of 

 the kind used in the colony are quite correft, and many are largely in 

 error ; of two instruments now in the Government Laboratory one gives 

 readings ~ v and the other y^ of a per cent, too low at the 96th division 

 or standard for sugar shipped to the American Market. All the other 

 apparatus used in polarizing — scales, weights, measuring flasks and 

 polariscope tubes — may be, and frequently is incorrect, especially the 

 flasks and tubes. In my Annual Report for 1886 I showed that one of 

 the measuring flasks that I examined, amongst a number of others, all 

 incorrect, was so badly graduated that it would cause an error of T 7 n of 

 a per cent, in the testing of a sample of sugar. This large error was 

 simply caused by the flask holding 5 fluid grains of water more than it 

 should have done. Polariscope tubes should be exactly 200 millimetres 

 long, but they also are frequently inexadt and a single millimetre or ^ 

 of an inch excess or deficiency causes an error of a half of one 

 per cent. 



All the amateur polarizations in this colony are done without regard 

 to these points— the accuracy of the apparatus being taken for granted 

 — and if they happen to turn out right it is merely by accident. In 

 establishing professional polarizers it would be necessary, therefore, 



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