218 THE ROYAL INSTITUTIOX OF GREAT BRITAIN. 



propriety 1)0 called a body, for it appears in some respects to be wholly different 

 from tuno-ible matter, wliile it has other qualities in common with it. Such are 

 the ditliculties of laying down general laws on so comprehensive a scale that we 

 shall iind it more secure to be contented to proceed gradually by closer induc- 

 tions in particular cases. We shall, however, be seldom much embarrassed in 

 the choice of a mode of argumentation. The laws of motion, which will be the 

 first immediate subject of discussion, have indeed sometimes been referred to 

 experimental evidence, but we shall be able to deduce them all in a satisfactory 

 manner, by means of our general axiom, from reasonings purely mathematical, 

 whicii, wherever they are applicable, are imquestional)ly preferable to the imper- 

 fect evidence of the senses, employed in experimental investigations." 



X. — Summary of dr. toukg's course of lectures. 



A scientific publication* of that epoch takes the following notice of the work 

 of we have just been speaking : 



*' When iJr. Young accepted the chair of physics in the Royal Institution, he 

 regarded that position as demanding of him something else than a simple com- 

 pilation from elementary treatises ; consequently he engaged in researches among 

 original authorities, in examining attentively and uniting in a single system all 

 that related to the principles csf mechanical science, and all that could contrib- 

 ute to the improvement of the useful arts. In following this plan he has reduced 

 the fundamental doctrine of movement to simple mathematical axioms in a more 

 immediate manner than had before been done, and he has facilitated the appli- 

 cation of those principles to all the cases which present themselves in practice. 

 He has investigated 1)3' a great number of experiments the force or tenacity of 

 materials of every kind ; a labor of which the results are highly important to 

 the engineer and the architect. He has simplified, extended and elucidated the 

 theory of the movement of waves, that of the circulation of the blood, and of 

 the propagation of sound. He has studied the curvature of images produced by 

 lenses and mirrors ; he has examined in detail the functions of the eye, and rep- 

 resented in a very comprehensive and very exact manner the phenomena of colored 

 light ; he has also pointed out some new cases of the production of colors. He 

 has reduced the theory of tides to a very simple form ; and his researches on the 

 cohesion and capiUary action of fluids are anterior to those of M. de Laplace. 

 He has made different comparative experiments on the elasticity of the steam of 

 boiling water, on evaporation and the hygrometric indications; in fine, his work 

 is strewn, to a large extent, with new inventions and practical applications. 



'* The second volume begins with the mathematical elements of the physical 

 sciences. Here are found all the propositions requisite for forming a complete 

 series of demonstrations applicable to all the important cases wdiich occur in that 

 depai'tment of scientific inquiry. Tlie author has excluded only some of the 

 more complex calculations of astronomy. A considerable portion of the volume 

 is occu])ied 1)}^ a comprehensive catalogue of works relating to physics and the 

 arts, methodically subdivided, and accompanied W'ith such strictures as, in the 

 judgment of the author, w'ere due to their respective degrees of merit. 



XI. — TnE COURSE OF .\ATURAL PHILOSOPHY GIVEN AT THE ROYAL INSTITU- 

 TIOX BY DOCTOR DALTOX. 



After the retirement of Young, Dalton.f the celebrated author of the atomic 

 theory, was invited to London to give a course of natural philosophy at the 



* Nlchulson's Journnl. Our extract is derived from tlie Bibliotheque Britannique, t. xxxvii, 

 No. 4, April, l^{>ii. 



t John Dalton, born September 5, 17G6, at Eaglesfiekl, in Cumberland, died July 27, 

 1844, at Manchester, where he had passed his lite in niakiuj^ chemical analyses for the 

 manufacturers, the price of which varied from a few shillings to a sovereign, and in giving 



