249
during his last illness, he evinced just apprehensions
of God and religion, and experienced the tranquillity
of mind which can arise from no other source. As
a man of science, he was far in advance of the age
in which he lived; and the zeal with which he propa-
gated Hervey's beautiful discovery of the circulation
of the blood, is a proof of liberality of feeling which
was by no means common at that period among
medical men, by whom the doctrine of the circulation
was long treated as a heresy in science, and its dis-
coverer nearly persecuted out of the profession.
That his disposition was generous and friendly in a
remarkable degree is beyond doubt, and the reader
may find a striking instance of it in the life of Ruddi-
man.
Dr. Pitcairne died in Edinburgh on the 2Oth of
October, 1713, in the sixty-first year of his age, and
was interred in the Grayfriars' Churchyard.
PITSLIGO, LORD.   See FORBES (ALEXANDER).
PLAYFAIR, JOHN, an eminent natural philoso-
pher and mathematician, was the eldest son of James
Playfair, minister of Benvie, in Forfarshire, where
he was born on the 10th of March, 1748. He was
educated at home until he reached the age of four-
teen, when he was sent to the university of St. An-
drews, where it was intended that he should study
for the Scottish church. The precocity of talent ex-
hibited by great men, frequently so ill authenticated,
has been strikingly vouched by two remarkable cir-
cumstances in the early history of Playfair. While
a student at St. Andrews, Professor Wilkie, the
author of the Epigoniad, when in bad health selected
him to deliver lectures on natural philosophy to the
class; and in the year 1766, when only eighteen
years of age, he felt himself qualified to compete as
a candidate for the chair of mathematics in the
Marischal College of Aberdeen. In this his confid-
ence in his powers was justified by the event. Of
six candidates, two only excelled him—Dr. Trail,
who was appointed to the chair, and Dr. Hamilton,
who afterwards succeeded to it.1
In 1769, having finished his courses at the univer-
sity, Mr. Playfair lived for some time in Edinburgh,
in the enjoyment of the very select literary society of
the period. '' It would appear," says his biographer,2
"from letters published in the Life of the Late Prin-
cipal Hill, that, during this time, Mr. Playfair had
twice hopes of obtaining a permanent situation.
The nature of the first, which offered itself in 1769,
is not there specified, and is not known to any of his
own family; the second was the professorship of
natural philosophy in the university of St. Andrews,
vacant by the death of his friend Dr. Wilkie, which
took place in 1772. In this, which he earnestly
desired, and for which he was eminently qualified,
he was disappointed." During the same year his
father died, and the care of his mother, and of the
education of his father's young family, rendered the
acquisition of some permanent means of livelihood
more anxiously desirable. He was immediately
nominated by Lord Gray to his father's livings of
Liff and Benvie; but the right of presentation being
disputed, he was unable to enter on possession until
August, 1773. From that period his time was occu-
pied in attending to the duties of his charge, super-
intending the education of his brothers, and prose-
cuting his philosophical studies. In 1774 he made
an excursion to Perthshire, to witness the experi-
ments of Dr. Maskelyne, the astronomer royal, to
1  See life of ROBERT HAMILTON in this Collection.
2 His nephew, by whom a Life of Mr. Playfair was prefixed
to an edition of his works, published in 1822.
illustrate the principles of gravitation from the effect
of mountains in disturbing the plumb-line. A per-
manent friendship was at that time formed between
the two philosophers. "I met," says Playfair, in his
journal of a visit to London in 1782, "with a very
cordial reception from him (Dr. Maskelyne), and
found that an acquaintance contracted among wilds
and mountains is much more likely to be durable
than one made up in the bustle of a great city: nor
would I, by living in London for many years, have
become so well acquainted with this astronomer, as
I did by partaking of his hardships and labours on
Schehallien for a few days."
In 1779 Playfair's first scientific effort was given
to the public in an Essay on the Arithmetic of Im-
possible Quantities, published in the sixty-eighth vol-
ume of the Philosophical Transactions, In 1782 an
advantageous offer prompted him to give up his
living, and become tutor to Mr. Ferguson of Raith,
and his brother Sir Ronald Ferguson. It was at
this period that he paid the visit to London in which
he met Dr. Maskelyne. By that gentleman he was
introduced to some literary men, and to institutions
of literary or philosophical interest. Some of these
roused the calm enthusiasm for philosophical great-
ness which was one of the principal features of his
character. '' This," he says,'' was the first time that I
had seen the observatory of Greenwich, and I entered
with profound reverence into that temple of science,
where Flamstead, and Halley, and Bradley devoted
their days and their nights to the contemplation of
the heavens. The shades of these ancient sages
seemed still to hover round their former mansions,
inspiring their worthy successor with the love of
wisdom, and pointing out the road to immortality."
From his thirst after knowledge being untainted
by political or local prejudices, Playfair had early
turned himself to the important discoveries of the
continental algebraists, and was the first man of
eminence to introduce them to British notice. He
perceived the prejudices entertained on the subject
in England, and probably the discovery sharpened
his appetite for a subject which he found was almost
untouched. Speaking of Dr. Maskelyne, he says,
" He is much attached to the study of geometry, and
I am not sure that he is very deeply versed in the
late discoveries of the foreign algebraists. Indeed,
this seems to be somewhat the case with all the
English mathematicians: they despise their brethren
on the Continent, and think that everything great
in science must be for ever confined to the country
that produced Sir Isaac Newton." In the works of
an eminent natural philosopher one may search long
before he will find anything which shows in explicit
terms the exact discipline of mind or system of rea-
soning by which he has made it to happen that all
he has said has so much the appearance of being
truth; but a petty remark, disconnected with the
ordinary pursuits of the philosopher, may often
strikingly illustrate the operation of his mind, and
the means by which he has disciplined himself to
approach as near as possible to truth; and such
a passage occurring in this short diary, we beg
to insert it. "An anecdote of some Indians was
told, that struck me very much as holding up but
too exact a picture of many of our theories and rea-
sonings from analogy. Some American savages hav-
ing experienced the effects of gunpowder, and having
also accidentally become masters of a small quantity
of it, set themselves to examine it, with a design of
finding out what was its nature and how it was to
be procured. The oldest and wisest of the tribe,
after considering it attentively, pronounced it to be
a seed. A piece of ground was accordingly prepared