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Joseph
Henry | ||||
| DOCUMENTS
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"RECORD OF
EXPERIMENTS"
March 27th 1847 |
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Davy suggests that the greatest intensity of heat possible may be produced by the combination of the effect of the voltaic arc and the jet of the compound blow pipe1-- This would merely produce a greater quantity of heat without increasing the intensity. Dr Ure says the light of a flame may be increased while its heat is diminished.2 I
was very much struck
last night in going to bed to
observe the candle
in my hand surrounded with a series of perfectly distinct coloured
circles--the
perfect representation of Newtons rings.3 My eyes were slightly
inflamed
and particularly the one with which the coulered rings were most
distinctly
seen. The inner &A more distinctly exhibited ring was about 4
inches
in diameter the candle being about 15 inches from the eye. The order of
colour was yellow Red blue Yellow Red Blue &c. The diameter of the rings increased as the candle was removed from the eye. The plane of the rings was perpendicular to the line joining the eye and the candle and continued to be so when the candle was moved. I have often seen colours around the candle when I have got up from bed in the night before washing my eyes but never so distinctly have the rings been exhibited as on the present occasion. The effect is probably due to a film of mucus
spread
over the surface
of the eye and may perhaps be imitated by dipping the finger into a
Solution
of sugar and applying this to the eye. | ||||
| The order of
succession is that of the
transmitted light of Newtons
rin[g]s.Henry Papers, Smithsonian Archives. 1 Humphry Davy, "Some Researches on Flame," Phil. Trans., 1817, p. 74. 2 Andrew Ure (1778-1857) was a consulting chemist in London. DNB. We have not identified the source. 3 A reference to Sir Isaac Newton's
discovery
that
various spectra
in the form of circular rings are produced when light is either
reflected
from or transmitted through a thin film of varying thickness. The order
of the colors from reflected light differs from that due to transmitted
light. David Brewster, A Treatise on Optics (London, 1831), pp.
102-103.
See also Henry Papers, 3:390; |
