1915-16.] The “Geometria Organica” of Colin Maclaurin. 87 
V. — The “Geometria Organica” of Colin Maclaurin: A Historical 
and Critical Survey. By Charles Tweedie, M.A., B.Sc., Lecturer 
in Mathematics, Edinburgh University. 
(MS. received October 15, 1915. Bead December 6, 1915.) 
Introduction. 
Colin Maclaurin, the celebrated mathematician, was born in 1698 at 
Kilmodan in Argyllshire, where his father was minister of the parish. 
In 1709 he entered Glasgow University, where his mathematical talent 
rapidly developed under the fostering care of Professor Robert Simson. 
In 1717 he successfully competed for the Chair of Mathematics in the 
Marischal College of Aberdeen University. In 1719 he came directly under 
the personal influence of Newton, when on a visit to London, bearing with 
him the manuscript of the Geometria Organica , published in quarto in 
1720. The publication of this work immediately brought him into promi- 
nence in the scientific world. In 1725 he was, on the recommendation of 
Newton, elected to the Chair of Mathematics in Edinburgh University, 
which he occupied until his death in 1746. 
As a lecturer Maclaurin was a conspicuous success. He took great 
pains to make his subject as clear and attractive as possible, so much so 
that he made mathematics “ a fashionable study.” The labour of teaching 
his numerous students seriously curtailed the time he could spare for 
original research. In quantity his works do not bulk largely, but what he 
did produce was, in the main, of superlative quality, presented clearly and 
concisely. The Geometria Organica and the Geometrical Appendix to his 
Treatise on Algebra give him a place in the first rank of great geometers, 
forming as they do the basis of the theory of the Higher Plane Curves ; 
while his Treatise of Fluxions (1742) furnished an unassailable bulwark 
and text-book for the study of the Calculus. 
In a sense he may be regarded as a founder of the Royal Society of 
Edinburgh, for it was at his instigation that a Medical Society in Edinburgh 
was encouraged to broaden its field of research and develop into the 
Philosophical Society, which gave rise in its turn to the Royal Society of 
Edinburgh in 1783. 
§ 1. During comparatively recent years the study of geometrical science 
has been enriched by a number of publications dealing with the history of 
