New-York tribune., 1873-01-01
REVERSAL or THE SODIUM BAND.

This experiment was very fortunate in exhibiting
completely the reversal OF the sodium hDe giving a
black band in the full spectrum exactly where the yell
low band had appeared alone before The suddeDneSs
with which the black ue made its appearance was re-
markabe 1t seemed spring out in relief. The sodium
flame represented in the diagram was incosed within
chimney 80 as it of from the eyes Of the audi
ence and not interfere with the image on the screen
Mutually as well as physically every age Of the world
IA the Ouigrowth and offspring Of all preceding ages
Science proves itself TO genuine product Of nature
growing according TO this law We have no solution
OF continuity here Every great discovery has been duly
prepared for two ways; first by other discoveries
which rm its prelude, and secondly thrOughthe sharp
ening by exercise Of Tire intellectual instrument itself
Thus Ptoemy grew out OF Hipparohus, Copemeus out
OF both. Kepler out OF all three, and Newton OUT OF al
the four. Newton did Dot rise suddenly from the sea
Level the intellect to his amazing elevation Az the
time that he appeared the table land OF knowledge was
already high He jus, Ii Is true, above the table lana as
"A massive peak still he Is supported by IT, and great
part OF his absolute hight was the hight OF
humanity in his time. II is thus with the DIS
oovery Of Kirchhoh Much had been previously accom-
pshed this he mastered and then by the force OF ind
vidual genius went beyond It, lie replaced uhcertanty
by certainty, vagueneSs by dennlteness cOhuson "
order ana DO not thlnk thatNewton mas suter cat
to the discoveries that have maze ms name lmhloIJh
than KrohhOh has 10 the credit OF gathering up the
fragDentry knowledge OF ms une OF Vastly eSte9Gius
IT, and OF nfusng into 1t the life OF great prlnGlpeas 81
Splendid results have since been obtained In relation 10
which both England and america nave Payed an @ th
part but, splendid as they are they are Dut te
sequel and application OF the principles estapshed III
his Heidelberg laboratory by the German investigator
THE LECTURER's TAsR IN AMERICA.
Ibave now come almost 70 the end OF my task in this
cty ana. indeed I'm America. My desire has been TO
show you with little break Of continuity as possible
the past growth and present aspect OF department Of
science in which have labored some Of the greatest In
telects the world has ever seen My friend Prof Henry
in introducing me at Washington, spoke OF me az IN
APOSTLE but the only apostoate that intended to fulf
was 10 place in plain words my subject before you and
10 permit its own intrinsic attractions 10 act upon your
minds the Of experiment, have tried 10 place
before YOU the best which, under the circumstances
could be provided but trust that each experiment has
had distinct intellectual value for experiments ought
IN he the representatives and expOstOrs OF thoughts
Language addressed TO the eye as spoken words are 10
the ear association with Its context nothing Is more
impressive or instructive than fit experiments but
Dart from its context it rather suits the cOnurers pr
pose surprise than that purpose Of education which
ought 10 be the ruling motive OF the seientnc minq.
And now brief summary OF work wall not be out
of place Our present mastery over the laws and phe
R1o% We have seen the ancents busy with this prob
lem. but, like child who uses his arms aimessy Ior
want of the necessary muscular exercise so these early
men speculated vaguely and cODfusedy regarding gh
not having yet the discipline needed TO give eleaIness
"a their insight and rmness their group OF princ
pes They assured themselves OF the rectllinea prop
cation Of Light and thai the a3gG & 0I ienes tSsn on @
sand yearsI might say, indeed, for more than lOo
years subseQuentyth scientific intellect appears as
smtten with paralysis the fact being that during TINS
time fhe mental force which might have IN the d.
reetion OF science, was diverted INTO otner
THE cAREER OF OPTICS OUTLINED
The oourse OF investigation regards light was re-
sumed in 100 by an Arabian philosopher named Aha
zan Then Il was taken up in succession by Roger
bacon, yteIlio and Kepler These men, though failing
TO detect the principal which ruled the facts kept the
6re OF investigation constantly burning Iheh came
the Fundamental discovery Of sne that cornerstone OF
optics as I have already called II, and immediatey
afterward we have the application by Descartes OF
epeIps discovery to the explanation OF the rainbow.
Tben oame Eowton's crowningI.e xperments on the
snaIysis and syntbess OF white ngbt W Wmsh 81 mas
proved 10 be compounded Of various Kinds Of hsAs OF
Siserent &c grees OF refrang gbility. -
~ e5s an impulse was given 70 optics by astronomy
tn tst year Olaf R0epeT, Learned Dane was enEagod