_Newton enters Trinity College, Cambridge—Origin of his Propensity
for Mathematics—He studies the Geometry of Descartes unassisted—
Purchases a Prism—Revises Dr. Harrow’s Optical Lectures—Dr.
Barrow’s Opinion respecting Colours—Takes his Degrees—Is appointed
a Fellow of Trinity College—Succeeds Dr. Barrow in the Lucasian
Chair of Mathematics._
To a young mind thirsting for knowledge, and ambitious of the
distinction which it brings, the transition from a village school
to a university like that of Cambridge,—from the absolute solitude
of thought to the society of men imbued with all the literature and
science of the age,—must be one of eventful interest. To Newton it was
a source of peculiar excitement. The history of science affords many
examples where the young aspirant had been early initiated into her
mysteries, and had even exercised his powers of invention and discovery
before he was admitted within the walls of a college; but he who was to
give philosophy her laws did not exhibit such early talent; no friendly
counsel regulated his youthful studies, and no work of scientific
eminence seems to have guided him in his course. In yielding to the
impulse of his mechanical genius, his mind obeyed the laws of its own
natural expansion, and, following the line of least resistance, it was
thus drawn aside from the strongholds with which it was destined to
grapple.
When Newton, therefore, arrived at Trinity College, he brought with
him a more slender portion of science than falls to the lot of
ordinary scholars; but this state of his acquirements was perhaps not
unfavourable to the development of his powers. Unexhausted by premature
growth, and invigorated by healthful repose, his mind was the better
fitted to make those vigorous and rapid shoots which soon covered with
foliage and with fruit the genial soil to which it had been transferred.
Cambridge was consequently the real birthplace of Newton’s genius. Her
teachers fostered his earliest studies;—her institutions sustained his
mightiest efforts;—and within her precincts were all his discoveries
made and perfected. When he was called to higher official functions,
his disciples kept up the pre-eminence of their master’s philosophy,
and their successors have maintained this seat of learning in the
fulness of its glory, and rendered it the most distinguished among the
universities of Europe.
It was on the 5th of June, 1660, in the 18th year of his age, that
Newton was admitted into Trinity College, Cambridge, during the same
year that Dr. Barrow was elected professor of Greek in the university.
His attention was first turned to the study of mathematics by a desire
to inquire into the truth of judicial astrology; and he is said to have
discovered the folly of that study by erecting a figure with the aid
of one or two of the problems of Euclid. The propositions contained in
this ancient system of geometry he regarded as self-evident truths; and
without any preliminary study he made himself master of Descartes’s
Geometry by his genius and patient application. This neglect of the
elementary truths of geometry he afterward regarded as a mistake in
his mathematical studies, and he expressed to Dr. Pemberton his regret
that “he had applied himself to the works of Descartes, and other
algebraic writers, before he had considered the elements of Euclid with
that attention which so excellent a writer deserved.[7] Dr. Wallis’s
Arithmetic of Infinites, Saunderson’s Logic, and the Optics of Kepler
were among the books which he had studied with care. On these works he
wrote comments during their perusal; and so great was his progress,
that he is reported to have found himself more deeply versed in some
branches of knowledge than the tutor who directed his studies.
Neither history nor tradition has handed down to us any particular
account of his progress during the first three years that he spent at
Cambridge. It appears from a statement of his expenses, that in 1664
he purchased a prism, for the purpose, as has been said, of examining
Descartes’s theory of colours; and it is stated by Mr. Conduit, that
he soon established his own views on the subject, and detected the
errors in those of the French philosopher. This, however, does not
seem to have been the case. Had he discovered the composition of light
in 1664 or 1665, it is not likely that he would have withheld it, not
only from the Royal Society, but from his own friends at Cambridge till
the year 1671. His friend and tutor, Dr. Barrow, was made Lucasian
Professor of Mathematics in 1663, and the optical lectures which he
afterward delivered were published in 1669. In the preface of this work
he acknowledges his obligations to his colleague, Mr. Isaac Newton,[8]
for having revised the MSS., and corrected several oversights, and
made some important suggestions. In the twelfth lecture there are
some observations on the nature and origin of colours, which Newton
could not have permitted his friend to publish had he been then in
possession of their true theory. According to Dr. Barrow, _White_ is
that which discharges a copious light equally clear in every direction;
_Black_ is that which does not emit light at all, or which does it very
sparingly. _Red_ is that which emits a light more clear than usual, but
interrupted by shady interstices. _Blue_ is that which discharges a
rarified light, as in bodies which consist of white and black particles
arranged alternately. _Green_ is nearly allied to blue. _Yellow_ is
a mixture of much white and a little red; and _Purple_ consists of a
great deal of blue mixed with a small portion of red. The blue colour
of the sea arises from the whiteness of the salt which it contains,
mixed with the blackness of the pure water in which the salt is
dissolved; and the blueness of the shadows of bodies, seen at the same
time by candle and daylight, arises from the whiteness of the paper
mixed with the faint light or blackness of the twilight. These opinions
savour so little of genuine philosophy that they must have attracted
the observation of Newton, and had he discovered at that time that
white was a mixture of all the colours, and black a privation of them
all, he could not have permitted the absurd speculations of his master
to pass uncorrected.
That Newton had not distinguished himself by any positive discovery
so early as 1664 or 1665, may be inferred also from the circumstances
which attended the competition for the law fellowship of Trinity
College. The candidates for this appointment were himself and Mr.
Robert Uvedale; and Dr. Barrow, then Master of Trinity, having found
them perfectly equal in their attainments, conferred the fellowship on
Mr. Uvedale as the senior candidate.
In the books of the university, Newton is recorded as having been
admitted sub-sizer in 1661. He became a scholar in 1664. In 1665 he
took his degree of Bachelor of Arts, and in 1666, in consequence of
the breaking out of the plague, he retired to Woolsthorpe. In 1667 he
was made Junior Fellow. In 1668 he took his degree of Master of Arts,
and in the same year he was appointed to a Senior Fellowship. In 1669,
when Dr. Barrow had resolved to devote his attention to theology, he
resigned the Lucasian Professorship of Mathematics in favour of Newton,
who may now be considered as having entered upon that brilliant career
of discovery the history of which will form the subject of some of the
following chapters.