138 Royal Society. 



junction with his friend Professor Playfair, was, in the early part 

 of the present century, an ardent vindicator of the opinions of Dr. 

 Hutton ; and it was with a view to the removal of some of the more 

 popular and startling objections to his theory, that he undertook, 

 and continued during several years, those memorable experiments 

 upon the effects of compression in modifying the action of heat, 

 which have contributed so greatly to the termination of the contro- 

 versies which were then agitated with so much warmth and severity. 

 These experiments, most happily conceived, and executed with sin- 

 gular boldness and perseverance, completely proved that the most re- 

 fractory substances may be made fusible by confining the elasticity 

 of the gaseous parts contained in them. Thus, pounded carbonate of 

 lime or chalk could be rendered fusible, without calcination, and 

 became, upon cooling, a compact stony mass, and even crystalline, 

 like marble ; it thus appeared that the effect of heat, acting under 

 enormous pressures, would not necessarily dissipate the gaseous and 

 evaporable parts of the strata of the earth, but would leave them to 

 form such new combinations or modifications of existence as might 

 be determined by the laws of crystallization or of chemical affini- 

 ties ; — a most important fact, and one apparently so difficult to esta- 

 blish in a form which might bring into action those gigantic forces 

 which present themselves in the great operations of nature, as would 

 have checked the attempts of any man who was not urged onward 

 by the most determined enthusiasm in the defence of a favourite 

 theory.* 



Sir James Hall's work on the Origin of Gothic Architecture 

 cannot be considered as a serious archaeological inquiry, but rather 

 as an agreeable exercise of his fancy. The development however 

 of his theory is singularly ingenious and elegant ; it proves him to 

 have possessed no mean talents as an artist, and shows a mind 

 alive to all those beautiful combinations of nature which seem to 

 be rendered fixed and permanent in the naves of our Gothic 

 cathedrals, and in the tracery of our decorated windows. 



Sir James Mackintosh was born in Morayshire in Scotland, in 

 1765 ; he was the son of an officer, of good family, but of very 

 limited fortune ; his first destination was for the profession of medi- 

 cine, and with this view he took the degree of M.D. at Edinburgh, 

 in 1787. Upon his removal, however, to London, shortly afterwards, 

 he abandoned his medical prospects, and gave himself up entirely 

 to the study of the law, and of moral and political philosophy. In 

 1789 he went to Leyden, where he studied for some time, and after- 

 wards to Liege, where lie was a witness of the memorable struggle 

 between the Prince Bishop and his subjects, as well as of many other 

 ebullitions of popular feelings which preceded and foreboded the 

 French Revolution. It was, probably, the contemplation of scenes 

 like these, as well as the observation of the corruptions and abuses 



* Sir James Hall's " Account of a Series of Experiments, showing the 

 Effects of Compression in modifying the Action of Heat," and his if Cata- 

 logue of Specimens," showing the results of those experiments, will be 

 found in Phil. Mag. vols. xxiv. and xxv. — Edit. 



