ULTRA-VIOLET RAY AS DETECTIVE

Taranaki Daily News, 23 March 1935, Page 16 (Supplement)

ULTRA-VIOLET RAY AS DETECTIVE

Becoming Of Service' In War Against Crime T AND KNOWS AN EGG’S AGE BY LOOKING AT IT! 'THE scientific detective—with an eye more penetrating than any of the celebrated detectives of fiction—has arrived. This is the ultra-violet ray, known to most people solely for its great curative powers. Its scope of detection is so wide that it is becoming of great service, not only in certain classes of crime detection, but also to people so differently occupied as Customs officers, analysts, museum curators and stamp collectors (says a special correspondent in . the “Daily Telegraph”). It has been discovered that the ray has a marvellous range of service, and all over the world scientists are experimenting with its ever-increas-ing uses as a detector. “This study is as yet only in its infancy,” I was told by Dr Julius Grant, a well-known analyst, who has made a special. study of the subject. “We who are experimenting with it are constantly adding to our store of knowledge of its possibilities.” Various branches of crime will be made mote difficult because of the growing uses to which this knowledge is being put. In connection with foodstuff frauds the ray has many uses. It can, in many cases, detect the adulteration of food, such as butter, coffee, milk and flour, merely by revealing a colour foreign to the normal article. As an illustration, milk subjected to the rays develops a canary yellow colour, but if even a trace of sodium salicylate has been added the colour changes to a bluish white. Eggs cannot conceal their age from this detective. According to Dr Grant, the serum or white of the egg changes its colour by minute degrees as the egg grows older, and while the change is invisible to the naked eye, it cannot escape the ultra-violet ray,. The ray is also able to. tell if the marks of origin of imported eggs have been obliterated, by making the erasure visible again. Recent experiments have also disclosed a new sphere of activity for this scientific detective. It has been discovered that under the rays the microscope can reveal cultures in organisms which were unknown to students using the ordinary white light.