36 FRAGMENTS OF SCIENCE. 
refer to the excellent researches of Professor Stokes at the 
opposite end of the spectrum. The above results consti- 
tute a kind of complement to his discoveries. Professor 
Stokes named the phenomena which he has discovered and 
investigated Fluorescence; for the new phenomena here 
described I have proposed the term Calorescence. He, by 
the interposition of a proper medium, so lowered the re- 
frangibility of the ultra-violet rays of the spectrum as to 
render them visible. Here, by the interposition of the 
platinum foil, the refrangibility of the ultra-red rays is so 
exulted as to render them visible. Looking through a 
prism at the incandescent image of the carbon points, the 
light of the image is decomposed, and a complete spectrum 
is obtained. The invisible rays of the electric light, re- 
molded by the atoms of the platinum, shine thus visibly 
forth; ultra-red rays being converted into red, orange, 
yellow, green, blue," indigo, violet, and ultra-violet ones. 
Could we, moreover, raise the original source of rays to a 
sufficiently high temperature, we might not only obtain 
from the dark rays of such a source a single incandescent 
image, but from the dark rays of this image we might 
obtain a second one, from the dark rays of the second a 
third, and so on a series of complete images and spectra 
being thus extracted from the invisible emission of the 
primitive source.* 
*0n investigating the calorescence produced by rays transmitted 
through glasses of various colors, it was found that in the case of 
certain specimens of blue glass, the platinum foil glowed with a 
pink or purplish light. The effect was not subjective, and consider- 
ations of obvious interest are suggested by it. Different kinds of 
black glass differ notably as to their power of transmitting radiant 
heat. When thin, some descriptions tint the sun with a greenish 
hue: others make it appear a glowing red without any trace of green. 
The latter are far more diathermic than the former. In fact, carbon 
when perfectly dissolved and incorporated with a good white glass, 
is highly transparent to the calorific rays, and by employing it as an 
absorbent the phenomena of "calorescence" may be obtained, 
though in a less striking form than with the iodine. The black 
glass chosen for thermometers, and intended to absorb completely 
the solar heat, may entirely fail in this object, if the glass in which 
the carbon is incorporated be colorless. To render the bulb of a 
thermometer a perfect absorbent, the glass ought in the first instance 
to be green. Soon after the discovery of fluorescence the late Dr. 
William Allen Miller pointed to the lime-light as an illustration of 
exalted refrangibility. Direct experiments have since entirely con- 
firmed the view expressed at page 210 of his wprk on " Chemistry." 
published in 1855, 
