New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1877-03-24
BLUE GLASS.

THE CHEMICAL RAY PARTLY INSTRUCTED BY II
WHITE GLASS BETTER AN UNSATISFACTORY
THEORY.
TO the Editor Of The Tribune
SIR: A good deal has been said and Wrltteh
recently about the curative effects Of light when mas
passed through blue glass Perhaps the most Instructive
and interesting material which this discussion supplies If
the illustration il furnishes OF that tendency OF the nina
10 pace fifth In the 20 ency Of what is unseen nyste-
ons uncOnprehendabe, and To regard such ia'h aS Il
legitimate spring OF action.
In recent issue of THE TRIBUNE ma Il let'er
on this tonic signed M D." This gentleman Gu
deavors 10 give scientific righteousness to the subject
aud what lie says aided by the initials he uses "ch
certainly suggest right to spcak VIII doubtless anee
many nersops vino like TO saved the trouble OF think
ing The arbitrary Classification OF the waveuhd'l"-
lions which constitute light into warm LUMINOUS anu
chemical rays il often convenient hui certainly III CT
roneons view of the phenomena. The vibrations eha-
Mating from the must be regarded "a luehtlci III
character differing only in their falidy nnd Amplitude
Some of them are capable affecting the retina some
the nerves which convey the sensation OF neat bu tEey
all act chemically; that is, they ancct 'he
combinations and dccompositions OF Substances
which react chemically upon each o'Aer' lHHS III
ordinary photography it is the so-calcd acllhc rays
those of hc refancblity at the violet ana blue eho
OF the spcctrum-which chiefly useful III taxing
nicurc Eut every one is that the heat rays ~
thc other end Of the spectrum are also most cei@ec
promoters chemical change and r'ie;i. fecc'o'i
will show that without them should have an moon
cciyabl, degree Of tanaon of all the chemical pro-
ce..cs connected with animate on inanimate nature
which 90 on upon the surface OF the earth.
If impossible to say that effect Is produced upon
pcrson who is exposed tn the light passing through
bIne glass but that Of various diseases may posi-
bl be effected by such treatment will strike most think
inc men as an exceedingly unlikely assumption. There
are pconc no doubt who that the whole light OF
heaven is c0lOrcd bluc by passing through biue giass
This is not so the glass only cuts of the yellow red ana
Green rays more less perfectly which would 0herWSc
IAN runn c uaticnt Ii acts ~ filter, keeping back
those srs ard lctn most Of the blue and violet pass
actc rays which the bues glass give us, and more
bedcs 50 tat II bluc glass at al 1t does 81 not 10y
bathing Us IN blue light, bus ny Withholding our u'ua
bath the other cOl0s, which together win pue go u
| make white.
ri D." evidently is Of opinion that actlnic action is
heightened BY the iutcrpOstOn Of glass OF an acunlI
color; hence its curative power. Ina this Is not t!t
! case he and Others easily demonstrate by nakllI
very simple experiment. Expose To sunlight sheet o
sensitive Iapcr-wbich any photographer will supply
under pieces blue and ordinary transparency Whi;t
glass placed SIDE by side it VIII be found that ihe
gradual lldehcHiUg OF the paper unHef tht Col"Ics'
| rla.s proceeds much rapidly than under tha'
which possesses any shade OF blue or Noitt whatsoever
Your corrrrIv1dcui prpnOrCCS something like bless
iur on the a0ors of Gen. Pcasontcn but venture IL
dCrbt whether be has read the Generals writings
in which be explains the rationale Of tie phenomena ht
mas Observed These writing, have certain (Sl col0sl
cab interest, bat sadly unsatisfactory when ludgeO
| by plain common sense j. o.
| 'Bdsktngoa d. g., Feb. 10, 1877.