102 



MATHEMATICAL AND PHYSICAL SCIENCE. 



[Diss. VI. 



this, can we talk of light as moving in straight lines 

 only 1 



(469.) We must now advert to the peculiar and disadvan- 

 Young'8 tageous manner in which Dr Young laid his farther 

 farther re- researches before the world. The optical papers in the 

 searches philosophical Transactions, ending with 1803, were 

 anony- the last which he published connected with his theory 

 mous. j n th a t work, although he continued to be Foreign Se- 

 cretary until his death twenty-five years afterwards, 

 and although during all that time he never ceased to 

 extend and perfect his views on the subject of his predi- 

 lection. The explanation of this paradox is to be found 

 principally in the strictness with which he interpreted 

 the allegiance which he owed to the medical profes- 

 sion. He had determined to be a practical physician ; 

 his early principles of action prevented him from 

 doing anything by halves ; and all experience affirmed, 

 that to gain confidence as a physician in the metropolis 

 he must cultivate sparingly, and as it were by stealth, 

 the studies of abstract science and of philology in which 

 he delighted. Unquestionably he was also disgusted 

 by the absence of one single supporter amongst the 

 members of the great society referred to, by the in- 

 jurious petulance of the then popular critical journal, 

 and by the impossibility under which he laboured 

 of communicating orally his knowledge to a general 

 audience in an interesting and acceptable manner. 

 The result of all this was the suppression of many of 

 his opinions, and the publication of others in so con- 

 cealed and uninviting a form that they remained 

 for years nearly buried and unknown to men of 

 science. He contributed a series of articles on sub- 

 His articles jects connected with light to the Quarterly Review ; 

 in the an d we may well smile at the abstruse and really ob- 

 RKvi, scure dissertations on detached points of science 

 often unmercifully loaded with algebra thus inter- 

 spersed with articles of popular criticism for the enter- 

 tainmen' of the reading public. From some of these 

 papers we may readily gather the soreness which he 

 felt at the cold reception of his discoveries. Farther 

 and still more important original speculations were 

 contained in a series of anonymous papers (sixty- 

 three in number) on a vast variety of subjects, both in 

 science and philology, contributed to the Encyclopce- 

 and Ency- dia JBritannica. It is not in a work such as this that 

 clopcedia we usua lly look for the first publication of great and 

 original views : the articles being anonymous could 

 only very gradually attract notice by their intrinsic 

 merit ; and the obscurity of some of those written by 

 Young rendered this difficult enough. But it is most 

 fortunate that he was induced thus to write : many of 

 his most original thoughts must have been lost but for 

 these concealed repositories. In the articles in the 

 Quarterly Review, for example, we watch with interest 

 the impression which contemporary discoveries made 

 upon his mind. The spheroidal wave of extraordinary 

 refraction is explained by unequal elasticity of the 



Review, 



JBritannica. 



crystal indifferent directions j 1 the discovery of polar- 

 ization by reflection is received with characteristic can- 

 dour, as giving a temporary blow to the undulatory 

 theory ; 2 whilst in a later paper the cause of chromatic 

 polarization is convincingly deduced from the prin- 

 ciple of interferences, and in the space of two lines 

 the peculiar coloured laminae occurring in Iceland 

 spar, which had been noticed by several experi- 

 menters, are accounted for. 3 



From about 1815 the optical discoveries of Young (470.) 

 were so intimately connected with those of his younger Theoi 7 f 

 friend and rival Fresnel, that it seems best to defer jighTde- 

 our account of them until we consider (in 3 of this ferred to 

 chapter) the peculiar researches of Fresnel, which 3 - 

 ultimately rendered the phenomena of polarization 

 the most impregnable position of the partizans of the 

 undulatory theory. The first great step was the con- 

 ception of transverse vibrations of ether, as constituting 

 polarization. This, as we shall see, was first pub- 

 lished by Young. It is to be regretted that the tardy 

 and imperfect publication of Fresnel's memoirs on 

 the one hand, and the resolution of Young to adhere 

 to an anonymous and indirect mode of announcing 

 his discoveries, on the other, render the history of 

 the subject sometimes obscure. The correspondence 

 between them, first fully published by Dr Peacock, 

 throws some light upon it; but several important 

 letters have not been recovered. 



I had intended devoting a portion of this section to (471.) 

 Dr Young's important and ingenious researches on the Physiolog; 

 physiology of vision. But the length to which it has al- visi 

 ready extended obliges me reluctantly to omit it. I also 

 refer to the chapter on mechanics (Art. 344, &c.) for 

 some notice of his masterly reasonings on the princi- 

 ples of carpentry and the flexure of elastic substances. 

 They are characterized by directness of purpose and 

 a consummate command of ordinary mathematics, 

 unaccompanied by any pretension to symbolical dis- 

 play ; it might be added too, by the obscure concise- 

 ness of Dr Young' s habitual style. His researches (pre- 

 ceding and anticipating those of Laplace) on capillary 

 attraction have also been referred to (432), as well as 

 his masterly investigation of the tides (80, 81). Itinterpre- 

 does not belong to this treatise to speak of his disco- ^ 

 very of the interpretation of hieroglyphics in certain v ^- lcs " 

 cases which gave the first real impulse to this obscure 

 but interesting subject. The successes of Champollion, 

 Rawlinson, and others, in similar undertakings, must 

 logically be connected with the first great step of de- 

 cyphering the polyglot stone of Rosetta. It may safely 

 be affirmed that no philologer ever before made such 

 a discovery in science as the law of interference, and 

 that no natural philosopher ever made such a step 

 in the interpretation of a lost tongue as the forma- 

 tion (up to a certain point) of an Egyptian alphabet. 



We cannot close this imperfect sketch of one of (472.) 

 the greatest ornaments of our age and nation, without 



1 Quart. Rev., vol. ii. 



2 Ibid., vol. iii. 



3 Ibid., vol. xi. 



