Volume 3 > Half-Volume 6

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made one brilliant discovery before his early death.
His place was nobly supplied, as regards the theo-
retical and mathematical part of the work, by
Fresnel; but it is to Brewster that we owe nearly all
the most important of the concomitant experimental
results. With an amount of patient labour of which
few can form a conception, and with a singular ex-
perimental skill which rose superior to defects of
apparatus, he examined minutely every curious frag-
ment of transparent crystallized mineral which the
collections of his numerous scientific friends con-
tained. The tables of refractive indices and dis-
persive powers which he thus framed would alone,
and even with improved instrumental means, repre-
sent the results of no mean labour. The same may
be said of his tables of the polarizing angles of
various reflecting surfaces, and of innumerable other
tedious investigations, apparently gone into at first
with the sole object of discovering facts, and not
laws." In apologizing for his scientific errors, es-
pecially on the subject of light, the writer adds,
"Liebig is reported to have said, 'Show me the
man who never made a mistake and I will show you
one who never made a discovery.' The mistakes or
misconceptions into which Brewster fell were nearly
all connected with the theoretical or mathematical
part of a subject; very rarely indeed with the experi-
mental. We may wonder that he never explicitly
adopted the undulatory theory of light; let us ask,
what should we have been inclined to do now had
we listened to the teaching of such masters as Laplace
and Poisson, to whom the greater part of the scien-
tific world deferred when Brewster was in the first
ardour of his career. . . . But the philosopher
who first discovered the existence of biaxial crystals,
the connection of the polarizing angle with the re-
fractive index, the production of double refraction by
irregular heating, and numerous other grand proper-
ties of matter�each, as it were, a leaven whose in-
fluence was widely felt, and which are even now
fundamental principles in science; who explained
thoroughly hosts of more simple yet paradoxical
phenomena, such as the colours of mother-of-pearl;
and who, besides all this, wrote not merely with the
earnest exactitude of the true man of science, but
sometimes with the impassioned language and verbal
imagery of the poet;�such a philosopher appears
but rarely, and never fails to leave his mark behind
him."
It would have been strange, however, if this pro-
gress, so like a triumphal procession, had been
unaccompanied by the slave behind the chariot and
his dispiriting whisper; and Sir David, amidst his
successes, was followed by an evil influence that
often marred his satisfaction by depriving him of the
reputation of many of his discoveries. The source
of annoyance is thus explained by the writer from
whom the foregoing passages have been quoted:�
"Unfortunately, Brewster's turn of mind was not
mathematical, and when he sought to discover the
laws of the phenomena which were deducible from
his patient measurements, he often found the second
task harder than the first. Sometimes, by a species
of trial and error, he succeeded brilliantly, as in his
discovery (from the two series of researches we have
just already mentioned) that the index of refraction
of a substance is the tangent of its polarizing angle.
More often the mere mathematician stepped in, took
the toilsome, elaborated facts, and from them in a
few minutes deduced (sometimes taking the whole
credit of it) the law he would have been utterly
unable to seek experimentally. It seems to us that
sufficient allowance has not been made for the natural
irritation which such treatment was certain to cause,
especially in a high-souled and single-minded man
incapable of treating others as he felt himself treated.
His biographer will have a painful, but a necessary
and salutary, task to perform in gibbeting such thank-
less parasites. Many a much-praised scientific article,
nay, even volume, may be found, where the facts are
taken mainly from Brewster, though his name is not
even mentioned. He was driven by such treatment
into frequent disputes about priority, and in general
he was successful, though often, before the final
settlement of the question, the obnoxious paper had
found its way to a non-scientific public, and even to
foreign journals. It is always a difficult matter to
determine what the proper course of a philosopher
should be under such circumstances. Few have the
calmness to rely upon the almost invariably just
decision of posterity; and most of those who do so
go unrecognized to their graves."
After his appointment to the office of principal of
the university of Edinburgh, Sir David Brewster
regularly resided in our northern capital, where he
was recognized both by natives and strangers as its
chief living celebrity. His active person, unbroken
by years, and his white, venerable head attracted the
reverence of those who passed him in the streets;
while in every company the unassuming style of his
conversation, and the intelligence with which it over-
flowed, made him a welcome guest. His ardour in
the prosecution of science also continued unabated,
so that until within a few days�perhaps it might be
even said within a few hours�of his death he was
employed in his favourite investigations. To him
indeed nature was a gospel on which a revelation was
written by the finger of its Creator, and he regarded
it as his sacred mission to decipher these written
characters and proclaim them to the world. To him
indeed the study of a phenomenon in science was
not merely an intellectual, but a devotional act. Of
this reverential appreciation of his allotted work the
following incident was told a few days after his death
by a relative who dwelt with him. " When we were
living in his house at St. Andrews twelve years ago
he was much occupied with the microscope; and as
was his custom always, he used to sit up studying it
after the rest of the household had gone to bed. I
often crept back into the room on the pretence of
having letters to write or something to finish, but
just to watch him. After a little he would forget
that I was there, and I have seen lam suddenly
throw himself back in his chair, lift up his hands,
and exclaim, 'Good God! good God! how marvel-
lous are thy works !'" Remembering these scenes
of which he had been informed by the above-men-
tioned relative, Sir J. Y. Simpson, the medical
attendant of the death-bed of Sir David, adds, "I
said to him on Sunday morning (the day before he
died), that it had been given to him to show forth
much of God's great and marvellous works; and he
answered, 'Yes, I found them to be great and mar-
vellous, and I have felt them to be his.'"
During the later years of his long life Sir David
had suffered repeated attacks of serious illness, but his
death was occasioned by an attack of pneumonia and
bronchitis. This occurred at his seat of Allerly,
near Melrose, on Monday evening, the loth of Feb-
ruary, 1868, in the eighty-seventh year of his age.
Even to the last his attachment to science was undi-
minished, and his solicitude about its progress was
manifested on more than one occasion. He wrote
calm and considerate farewell letters to the various
scientific societies with which he was connected, and
among whom his memory is still affectionately cher-
ished. A week before his death he wrote a long
letter in his own handwriting, and characterized by