New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1872-12-16
PROF. TYNDALDS TOPICS.

From r7< Un,,sd STATES Railroad Ifiaia9 Rsgst~.
That the expectation OF pleasure and profit
from the of lectures which Prof Tyndal has pre-
narpd for delivery in country not likely 10 be dis
appointed will appear from the following chreiu anay-
his theme Light and Heat a. he has arranged Ior
lie begins in a predatory way, and dwells upon the
Introduction Of the experimental method INTO science
sneaks of the srdor Of Investigators and OF their
wards. he seeks 81 show that most OF them wrought
for the Of knowledge, and with no practical emu IN
view though their discoveries Travelled to the most
astonishing practical applcanOna lnsFhhehl MS are e1-
paned aud the principles upon which they depend ne
points Oul the prOXluate aud action OF the cleo
fric light which to be used IN the ILLUSTRATIONS Ihe
laws OF reflection demonstrated, and one or two
striking practical applications addueed Ihen ne goes
on no refraction. RefactOn Is followed by an inquiry
into the constitution OF nght It's analysis anu snheSS'
This occupies the first lecture.
In the second lecture tho Demonstrated constitution OF
light applied the doctrine OF cOlOrs de goes very
thoroughly and plainly into thus matter, making per
feetly evident the causes on when ordinary eGio5 e
and blue light when mixed together produce whlte ana
moi green. lie describes the difference between the
Emissions from solids and their yapors Metallic yapOrs
Are produced and shown vita their characteristic cOors
Their lt rs analy zed and Is shown 10 be distinctive Of
he substance from which It comes Spectrum aIaly SIS
IN his t1Td lecture Tyndan deals with solar Light,
dwelling upon the distinction between the bright lines
Of metallic vapOrs and the dark lines OI FraushnOer
The recprOcity OF radiation aud absorption Is demon
straied and IL shown experwentaly that an mean
descent Vapor aDsOrbs the hght whch II ents' Inis
leads 10 the theory Of the ply steal constitution OF the
mn Then he goes on 10 show the extension OF the
spectrum beyond lts visible range performing Win
qrartz prisIns and lenses Stokes's experiments on
dnorescence and rendering invisible rays visible. The
a5ber NE OF tine spectrum Is handled ITS
extension heat beyond the limits Oh IA, ngh IL. Is
ing poWeE OF the rays from the electric gnt are maus
fnsion and combustion being thus effected Here DC
e,nna the Famous FIorentine experiment OF the ini
ton of diamond In oxygen. using, however, teFres-
trial source OF radauf heat He also endeaVors 10 pro
duce combustion by concentrated by Lens OF ee
The heatrays then filtered rom the hghtrays ahc
IL shown that all the foregoing effects are produced Dy
rays totally beyond the range OF Vision i1s1n or
tion and explosion being produced &C foci perfectly
dark and far the air Il concerned perfectly eou
II ais these
of Evaporation IN the tropical and the work OF
fusion upon tie Alpine Ice ana SHOWS Inc rays, morc
over are shown be competent 10 raise platinum TO
xht neat that Intervention one may extract
trom the dark rays all colors OF the spectrum TINS
brings him 10 the end Of the third lecture.
In the fourth lecture ne shows the tendency 81 the
human mind 10 seek governing principles which rule
facts and correct them, rendering them 80 20 say,
organic He dwells upon the exercise OF the theorzng
yarEv taking Newton as an example. lie tries " snow
how naturally his optical theory gre" OUT VI MS
knowledge The aoctrine oi coOrs Is now eA.s i
nv the Introduction OF the cOlors or thin plates
al str,afed surfaces &c, ana he unrsyels the
subtle additions which Newton made IN ms .heo,y. IA
h. then contracted with the theory Of undulaton The
latter Is rendered familiar to the mind by preliminary
considerations regarding waer-waves, and p{ expert
ments regarding sound He dwes upon the labOrs OF
Thomas Young and the effect OF BroughAh sttasaH ~
the Bdsab~gh Reriep TINS wiz Do nus n oss an ~
lecture but he has wrought hard 10 make ~ clear anu
is essential 10 comprehension OF she oes
In the nth lecture Tyndall enters upon the pnsnoe
non OF capitalization. and seeks 10 give an eApanno
of crystalline architecture. The process OF
ton is expermenaly Illustrated Inis N u9no VIII
view 10 the action OF cry stalls upon light In the nrst
no deals vita cr solely with reference
20 the polarization Of Light. This eApaineu anu
The stat OF the two halves Of the divided beam are
dWelt upon Then the chromate phenomena on
nosrzed light The effects of mechanical strains aud
treasures in producing quasi crystalline STRUCTURE ala
exhibited Then tho simIar phenomena OF un'hheas0o
glass. They Will moro Than al the nith leisure 49,.
The lecture Is devoted % the inithor "hN Eh"
of the action oil crystals upon light untNa hnh haKa
olysss CIRCULAR polarization. tud lhe -hs'hH1S 'us0-'