1818.] Proceedings of Philosophical Societies. 63 



of Mica present under oblique Incidences ; Phenomena of 

 Polarization which are observed in Bodies imperfectly crystal- 

 lized ; Determination of the Laws according to which Light is 

 polarized at the Surface of Metals. 



The seventh and last chapter is on heat, both radiant and 

 latent ; it contains the following topics : on the Relations of 

 Light and Caloric ; Laws of the heating and cooling of Bodies 

 in undefined Media ; Influence of the State and Nature of 

 Surfaces upon the Radiation of Caloric ; Theory of its Equi- 

 librium by mutual Exchange ; Laws of the Propagation of Heat 

 in solid Bodies ; of the Capacity of Bodies for Caloric ; and of 

 Steam-Engines . 



This very ample table of contents will afford a clear proof of 

 the extensive view which M. Biot has taken of natural pheno- 

 mena ; and the manner in which he has treated all the different 

 topics equally prove the profound and elaborate spirit of philo- 

 sophical investigation for which this author is so justly distin- 

 guished. There is a general air of candour pervading every 

 part of the work, which is highly creditable to the author ; and 

 an appearance of dispassionate good sense, which produces a 

 feeling of confidence in all his statements. Different persons, 

 according to their turn of mind and previous pursuits, will form 

 different opinions respecting the propriety of introducing so 

 much of mathematic and algebraic reasoning ; but, admitting 

 the principle, the execution is highly commendable. The arrange- 

 ment of the materials is good, and its stile perspicuous ; and 

 it has very little, if any, of the obscurity which so frequently 

 pervades works of science, arising from the fanciful introduction 

 of new terms, or the no less fanciful employment of old terms 

 in new senses. Many readers will regret that M. Biot has not 

 given more of a regular historical detail in connexion with the 

 different topics on which he treats. It no doubt adds much to 

 the interest of works of this description, and seems a kind of 

 tribute due to our precursors in science. M. Biot seldom refers 

 to the labours of preceding authors, except in an incidental 

 manner, and does not seem to have conceived it a part of his 

 plan to state by whom the knowledge that we at present possess 

 was origiually discovered. 



Article XII. 



Proceedings of Philosophical Societies. 



ROYAL SOCIETY. 



The Society met on Nov. 6 ; but, in consequence of the death 



of the Princess Charlotte of Wales, the meeting was adjourned. 



Nov, 20. — Sir Everard Home read the Croonian Lecture, the 



