38 Royal Society. 



fields of science and of literature, lie has successfully collected 

 flowers from all, appropriating the well known passage of Lucretius, 



Fioriferis ut Apes in saltibus omnia libaut, 

 Omnia ncs. 



Yet, referring to an equally well known apology for his condensed 

 mode of writing, prefixed to the Aphorisms of Hippocrates, 



we may be allowed to hope that others of less powerful abilities or 

 of less persevering energy of mind, maj' concentrate the objects of 

 their research within the limits of some defined portion of science, 

 rather than make inadequate endeavours to embrace the whole. 



Davy. 



I am now led by the succession of melancholy events to that 

 portion of my duty on the present occasion, which is by far the 

 most painful to myself. 



With Wollaston and with Young 1 have been intimately ac- 

 quainted for many years; but Davy I have known from his child- 

 hood. I knew his parents, his family, and his relations. I witnessed 

 his commencement in science, and by recommending him, at that 

 decisive moment, to the patronage of Dr. Eeddoes, 1 maj' have had 

 the good fortune to fix and to smooth the splendid course which 

 has carried him to that pinnacle of Fame, which his abilities, his 

 energies, and inventive faculties, entitled iiim to attain. 



It may not be uninteresting here to notice the first experiment 

 that gave me a strong feeling of his merit, and which I believe has 

 never been laid before the public. 



Davy, then about seventeen, had formed an opinion adverse to 

 caloric, or to the materiality of heat, and he attempted an experi- 

 mentum critcis in tlie following manner : — Having procured a piece 

 of mechanism set in motion by a spring, he added two horizontal 

 plates of brass, the upper one carrying a small metallic cup, to be 

 filled with ice, revolved in contact with the lower. The whole ma- 

 chine, resting on a plate of ice, was covered bj' a glass receiver, 

 and the air exhausted. It was then allowed to move, when the 

 ice in the small cup was soon observed to mek ; and the conclusion 

 was drawn that this ert'ect could proceed from vibratory motion 

 alone, since the whole apparatus was insulated from all accession 

 of material heat by the frozen mass below, and by the vacuum 

 around it. 



This experiment does not, unquestionably, decide the important 

 matter in dispute with respect to our ethereal or transcendental 

 fluid ; but iew young men remote from the society of persons con- 

 versant with science, will I believe any where present themselves, 

 who are capable of devising any thing so ingenious, 



Davy continued his researches on the nature of heat after his 

 removal to Dr. Beddoes at Clifton in the autumn of 179S, and 

 published them in a provincial collection of tracts. This paper 



caught 



