I am versatile
My wonders did not cease in treating ailments alone. If I had the colour blue associated with me, I could also make light appear yellow when passing through the aqueous infusion of this wood and yet I seemed to emit blue light which reflected from the very same infusion.
You might wonder that I was restricted to botanical pursuits only, but you may be pleased to know that more recently, several highly fluorescent glucosyl-hydroxychalcones were isolated from this plant.
Have you heard of lapis solaris? It is a widely known stone called Barium sulphate. Galileo Galilei, after having received inspiration from the work of a Bolognian shoemaker, Vincenzo Casciarolo, confirmed my presence in the famous stone. Galilei said, “It must be explained how it happens that the light is conceived into the stone, and is given back after some time, as in childbirth.”
You must be remembering that I talked about kidney wood a little while ago. My existence was further investigated into by Robert Boyle in 1664 when he was inspired by Monardes’ report and investigated this system more fully. He discovered that after many infusions the wood lost its power to give colour to the water and concluded that there was some “essential salt” in the wood responsible for the effect. He also discovered that addition of acid abolished the colour and that addition of alkali brought it back.
I do not limit myself
And if you thought that I could limit myself to yellow and blue light alone, you are mistaken, my friend, for how can the colours not multiply when something as ‘moving’ as alcohol is around. And who could brew alcohol better than Mr. Brewster himself? David Brewster, in 1833, described that when a beam of white light passed through an alcohol solution of leaves a red beam could be observed from the side (which was of course chlorophyll fluorescence). He considered the effect due to “dispersion”.
John Herschel went a step further by calling me “epipolic dispersion” when he observed me for the first time in quinine sulphate. George Gabriel Stokes (1852) published his massive treatise “On the Change of Refrangibility of Light” – more than 100 pages. He initially used the term “dispersive reflection” to describe the phenomenon presented by quinine sulphate. Stokes used a prism to disperse the solar spectrum and illuminate a solution of quinine. He noted that there was no effect until the solution was placed in the ultraviolet region of the spectrum.
These observations led Stokes to proclaim that I am of longer wavelength than the exciting light, which led to this displacement being called the Stokes Shift. He also seems to have been the first to propose, in 1864, of my use as an analytical tool, in a lecture “On the application of the optical properties to detection and discrimination of organic substances”.
I did not create this illumination from quinine sulphate alone. I went on to emit light from calcium sulphate also upon being excited in the UV. This was noted by Becquerel where he says that the emission occurs at a wavelength longer than that of the incident light.
Adolph Von Baeyer, a German chemist, synthesized Spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one, 3′,6′-dihydroxy dervatives in 1871. He apparently coined the name “fluorescein”, from “fluo” and resorcin (resorcinol), which he reacted with phthalic anhydride.
All these famous scientists should give me credit for the fame that I have brought them, you know. For it is because of me that, in 1905, Adolph Von Baeyer was awarded the Nobel Prize in Chemistry “in recognition of his services in the advancement of organic chemistry and the chemical industry, through his work on organic dyes and hydroaromatic compounds”.
Following this were several incidents which resulted in the discovery and production of various compounds where I happened to be the principal characteristic factor.
