Animal Quinoidine

IT is a well-known fact that the nails, skin, teeth and bones fluoresce blue when exposed to a source of ultra-violet radiation.This is best seen by inter- posing between the source of radiation and the irradiated object a sheet of material which excludes the visible rays.While examining the properties of some of the yeast concentrates obtained in the course of another research, it was observed that these also showed a blue fluorescence.Specimens of normal urine are also known to behave similarly.The coincidence of these facts led to this work.We have found the following literature upon the subject of blue fluorescence in ultra-violet light in the animal organism.