Show biology supplies newest weapon for crime prevention tion new york crime prevention has gone into the biologists laboratory for its newest weapon fingerprint technique has been made more positive and accurate through the adoption of a staining solution known as flemmings emmings FI reagent which blackens the slight fatty deposit in fingerprints and makes the telltale marks show up plainly in many cases where they are too light and faint to be detected by methods previously used sciences newest aid to law enforcement comes through h the ingenuity ot of dr francis F lucas cas ot of the bell telephone laboratories here dr lucaj had noticed that on many finger prints the fine powder commonly me illy employed by the police technicians does docs not stick he knew that the stuff that holds the powder on a good finger print is a slight deposit of the blodys natural oil the problem therefore was to find something to make even a slight trace of this oily material highly visible biologists helped hun him ile he talked the problem over with some biological friends they told him ot of flemmings solution which has long been used in preparing tissues for microscopic examination it i a mixture of solutions of cosmic and c hromic chromic acid which turns any fatty or oily substance ance intensely black paper bearing bearin suspected fingerprints is first treated with flem solution and then dipped into a dye which under ultraviolet light glows with a brilliant blue green hue the fingerprint stands out black and stark against this shining background its finest details can be examined under a low power microscope cro scope or it can be photographed up to any enlargement desired it if the paper bears print or handwriting filters over the camera lens ions can cut off the ink from registering on the film leaving only the boldly showing fingerprints |