New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1874-04-21
NEW PUBLICATIONS.
THE SCIENTIFIC METHOD.

i H.
49,, ,,;thont except,ou been so absorbed i'll 'no
nanct ~ their researches as to take no
20 Tho nrinciples of their method OF the oonoi'i0
90 snccessfu issue. Their process mas peer Puioi9
,h;act;ve without an analysis Oh tue ineAi', ~,
-. essential TO the attainment OF uuth Inc
o,.;ra vicor of their minds has been gwen 10 INC
,,henomena of Nature; force OF reasoning mas pech
combined it is true, with keenness Oh oDserva''on'
Sut rarely have they made the attempt to discover
a.. s,ements of their method, and TO reduce the
processes of scientific research to scientific system
T. .ho resnect they have builded wiser than they
hnexp and erected a spacious and goodly edihce
without calculating the depth of it's foundation or
The strenQth of its materials The present WORK is
intended to supply the deficiency in the theory Oh
investigation. 1t is not adapted to facilitate the
labors of the explorer but to elucldate the eondl-
lions ON which all legitimate conclusions must be
based Regarding logic as the science OF the funda-
mental laws of thought, the author has aimed 10
exhibit the logical principles Of reasoning when are
involved in the true method of scientific research,
and has accordingly written in the interests OF
psychology rather than of physics. In his opinion
there is no such thing distinct method OF induc-
ton as contrasted with deduction, but induction is
simply an inverse employment of deduction Ihere
Ia at present reaction against the purely emplrlca
procedure of Bacon, and physicists have learned 10
advocate the use of hypothesis. Bacon Professor
Jevons maintains, although insisting upon constant
reference TO experience had no correct ideas as
logical method by which helaws Of nature are edueed
from particular facts. But the Hypothetical antlc
patton of nature is essential part OF nducuVe III
ouiry. The great triumphs of physical science are
due to the Newtcnian method OF deducuVe reasoning
combined with elaborate experimental Verlncation
From this point of departure the author proceeds
to show that the sciences of number and quantity
rpose upon the moro general science OF logic that
the theory of probability, which enables us 10 es
innate quantities of knowledge, involves the true
principle of inductive procedure, and that the
logical value of every inductive result must
be determined by the inverse method OF
probability. As the phenomena OF Nature
are manifested in quantities of time, space,
force energy the measurement of the various guam
titatiye conditions involved demand much employ
ment of scientific procedure. The author, accord
inglv. considers the methods by which exact meas
urement is effected, errors eliminated, probable
mean result attained and the probable error OF that
mean eliminated. He then illustrates the conditions
requisite for accurate observation successful expert
ment and the certain detection OF the quantitatlye
laws of Nature The details Of Professor Jeyonss
system, of which we have given the merest skeie-
ton are too profound in their character and too abb
struse in their method, for anything like popular
exposition in this place. but must be made the sub
ject of accurate study by the reader who wishes to
comprehend their application and bearing. Inc
work however is afluent in incidental discussions
OF the deepest interest remarkable for the wise dls
elimination Of their tone, the breadth and sagacty
of their Judgment, and their vigoI, and frequent
felicity of expression. few specimens of this kind
win be of value TO many thoughtful readers, and
we trust will tempt them to further acquaintance
with one of the most profound and suggestive works
Of the present year.
In the chapter on Experiment, which is full of
important directions to the cultvators of physical
science Professor Jevons presents several admirable
illustrations of the influence of unsuspected con-
ditions on the process of inquiry. The expermenter
is seldom of all the circumstances under which
his researches are made. Some power may be In
action which escapes the most vgilant examination
There little doubt that the alchemsts were mlsed
by the unsupported presence of traces Of gold and
silver in the substances they proposed to transmute
Lead as drawn from the smelting-furnace, almost
always contains certain amount of silver Gold is
associated with many other metals. Thus small
quantities of noble metal would often appear the
result of experiment and raise delusive hopes. In
many cases the presence of common salt In the ar
has caused great trouble. Although proved to exist
by Sir Humphry Davy it continued a stumbling
block in the science of spectrum analysis, and
probably prevented such men as Brewster, Herschel
and Talbot, from anticipating by thirty years the
discoveries of Bunsen and KirchO In the science of
radiant heat early inquirers were led to the con-
cuson that radiation proceeded from the surface Of
solid, or from very small depth below it. But they
happened to experiment upon surfaces covered by
coats Of varnish, which is highly impenetrable to
heat Had they varied the character of the surface,
by using q substance of opposite quality in that
respect like rock salt, they would have obtained
very different results One of the most extraordinary
instances of an erroneous opinion due to overlooking
the influence Of certain agencies is that concerning
the increase of rainfall near the earth's surface.
More than century ago it was observed that rain
gauges placed upon church-steeples house tops and
other elevated points gave considerably less rain
than If they on the ground. Many theories
have been started to account for the fact But the
author himself has shown as he believes. that it is
simply due to the interference of wind which defects
more OF less rain from all the gauges tnat ey
posed to it. The great magnetic power of irOn is
well known, makes il constant source of disturb
apce in magnetic experiments. In building q mag
netic observatory ii is necessary to take great
that no iron is employed in the construction, and
that no masses of iron are near at hand. In some
cases magnetic observations have been disturbed by
masses of iron ore in the neighborhoOd In Fara-
days experiments upon diamagnetic substances, he
took the greatest precautions against the presence
of any disturbing influence in the copper wire, wax,
paper, or other substances used In suspending the
test objects 1t his invariabe custom to try the
effect of the magnet upon the apparatus before at
tempting the main experiment. Professor Iyndau
has also employed the same mode for testing the
freedom of electromagnetic coils from iron. Even
In the very infancy of the science of magnetism,
Gilbert one Of the most acute of the early expert
menters accounted for the opinion existing In his