MATHEMATICAL AND PHYSICAL SCIENCE. 



[Diss. VI. 



ject 



Scheme of result of this attempt before the reader. During the 

 treatment lengthened period of composition of this Dissertation 

 of the sub- p ro t r actedby indisposition and untoward circumstances 

 of different kinds, I have had abundant leisure to reflect 

 on the advantages and disadvantages of a plan which I 

 had sketched in the previous paragraphs, at the very 

 opening of my task. I am aware that a rigid criti- 

 cism awaits every attempt like the present. I am 

 aware also, that it is far easier to detect real faults, 

 especially of omission,. -than to make sufficient allow- 

 ance for the exceeding difficulty and delicacy of the 

 undertaking. I have but one ground of confidence, 

 and that is so strong, that I trust it will enable me 

 calmly to meet every just critical reflection. I am 

 conscious of having written in a spirit of absolute 

 impartiality whether as regards persons or subjects, 

 and that I have exercised to the full amount of my 

 opportunities what powers of judgment I possess. 

 I have striven to speak judicially and historically 

 whether of friend or stranger, the dead or the living, 

 Englishman or Foreigner. What I have felt the 

 most constant effort, has been the needful exclusion 

 of meritorious names, far more numerous than those 

 especially included and dwelt upon in these pages. 

 But this has appeared to me the cardinal point of 

 my whole plan. The labourers in science have been 

 in these latter days so numerous, that had I noticed, 

 even briefly, every one who had made a real step in 

 science, my pages must have been crowded by names 

 and titles of books. Even with the extension of bulk 

 to which this essay has gradually and unavoidably 

 grown (nearly double of its projected amount), the 

 reader would rather have been bewildered than led by 

 the perusal of such a catalogue. Besides, since such 

 a brief historical synopsis forms very generally an in- 

 troduction to the several articles of the Encyclopaedia, 

 to repeat it all here would have been but a tedious re- 

 dundancy. No one conversant with such matters will 

 imagine that I have saved myself any labour by this 

 particularity of selection. On the contrary, it would 

 have cost no effort to enumerate under each subject 

 the living or recently deceased authors upon it who 

 are best known ; such a detail must have left a vague 

 and shadowy impression on the mind of the general 

 reader, and when regard is paid to the necessary limits 

 of the essay, and the multitude of technical details and 

 technical words which there is no space to define and 

 illustrate, it is plain that the perusal must have been 

 rendered as dry and unpalatable to those who seek 

 general and elementary yet clear ideas, as it would 

 have been tantalizing and unsatisfactory to the ac- 

 complished student, or to the man of science in 

 search of particular historical details. 

 (14.) The end at which I have aimed is to select the 

 more striking land-marks of progress in each subject 

 in each age, and endeavour to connect them with the 

 character and position of all the more eminent dis- 



coverers, thus conveying to the general reader suffi- 

 cient information on the limited number of particular 

 subjects discussed, and interesting him not only in 

 the science but in the individuals. Then, by a few 

 slighter touches only, and the mention of some 

 secondary names, to connect with one another these 

 brighter periods of eminent progress, in which every 

 country and every age feels a just pride. 



That by many I shall be considered to have dwelt (15.) 

 too much on some eras of invention, and to have 

 omitted others not less important, is a difference of 

 judgment which it is impossible not to anticipate, 

 but equally impossible to prevent. I will only add 

 that I have endeavoured to extend my impartiality 

 to subjects as well as to persons ; and that I have 

 not intentionally dwelt longer on the topics of my 

 own predilection than on> those naturally considered 

 by other persons equally or more important. Many 

 subjects as well as persons familiarly known to me 

 are scarcely, if at all, mentioned in these pages. To 

 leave some definite and vivid impressions, selected 

 solely for their importance, on the mind of my reader, 

 has been the great object constantly before me during 

 the composition of this work. 



It will be seen from the preceding paragraphs, ( 16 

 that I have deviated in some respects from the W ith*that of 

 scheme of my two distinguished predecessors in the the preced- 

 composition of the Dissertations on Science, Professor in g Diss 

 Playfair and Sir John Leslie. The essay of the for- tations< 

 mer, which is the more finished and methodical, is 

 admirably adapted to the period of the history of 

 science of which he had principally to treat; the 

 period, namely, of Galileo, Bacon, Newton, and 

 Leibnitz. But the amount of material was smaller, 

 and the principle of selection was also much simpler. 

 The positive science of that age might almost be re- 

 duced to two heads, Astronomy, including its mecha- 

 nical principles, and Optics. It was an age not more 

 distinguished for the Truths it disclosed, than for 

 the invention and right appreciation of the Methods 

 of Discovery. Inductive Logic, and Mathematical 

 Logic applied for the first time to dynamics, very 

 justly claimed a place in a dissertation on the pro- 

 gress of science, in a period when these preliminary 

 doctrines and discoveries were the stepping stones by 

 which even the basement story of the Temple of 

 Nature could alone be reached. The Philosophy of 

 Bacon and the discovery of Fluxions, occupied there- 

 fore, with much reason, a large portion of Professor 

 Playfair's beautiful Dissertation ; and it is impossible 

 to regret that an intellect so admirably qualified for 

 tracing and displaying the intimate and historical 

 connection of branches of knowledge so varied in 

 their principles and character, should have been thus 

 congenially employed, to the delight and edification 

 of readers of every degree of acquirement from the 

 highest to the humblest. 1 



1 In mentioning the name of my distinguished predecessor in the Chair of Natural Philosophy in the University of Edin- 

 burgh, I willingly take the opportunity of noticing, in a few words, his peculiar merits, to which the Dissertation contained in 



