Life of Sir Humphry Davy. 349 



clock-work, so contrived as to be set to work in an exhausted receiver, 

 he added two horizontal plates of brass ; the upper one, carrying a smah 1 

 metallic cup, to be filled with ice, revolved in contact with the lower one. 

 The whole machine, resting on a plate of ice, was covered by a glass 

 receiver, and the air was exhausted by a syringe; [ingeniously modified 

 for the purpose from an old glyster apparatus ;] for as yet he had no air- 

 pump, and, what is still more worthy of notice, had never seen one ! The 

 machine was now set in motion, when the ice in the small cup began to 

 melt; whence he inferred that this effect could alone proceed from 

 vibratory motion, since the whole apparatus was insulated from all acces- 

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

 around it.' 



The experiment was afterwards repeated under more favourable 

 circumstances, and the icsults published in an Essay on Heat, 

 Light, and the Combinations of Light; and it has been justly 

 observed by Mr. Gilbert, that though it does not at nil decide the 

 important matter in dispute, but few young men remote from the 

 society of persons conversant with science would be capable of 

 devising anything so ingenious. 



The introduction of Davy to Mr. Davies Gilbert about this time 

 was perhaps one of the most influential circumstances in his life. 

 Mr. Gilbert's attention was attracted to him, as he was carelessly 

 swinging on the hatch or half-gate of Mr. Borlace's house, by the 

 humorous contortions into which he threw his features ; and being 

 told he was fond of making chemical experiments, he spoke to him; 

 soon discovered ample evidence of his singular genius, and after 

 several interviews, offered him the use of his library, or any other 

 assistance he might require in the pursuit of his studies, and gave 

 him an invitation to his house at Tredrea, of which Davy frequently 

 availed himself. The tumultuous delight which he expressed on 

 seeing', for the first time, a quantity of chemical apparatus, and an 

 air-pump, is described by Mr. Gilbert as surpassing all description. 



Soon after, Davy's acquaintance commenced with Mr. Gregory 

 Watt, who came to Penzance on account of his health, and lodged 

 in the house of his mother. 



' Davy sought to ingratiate himself with Mr. Watt by metaphysical 

 discussions ; but instead of admiration, he excited the disgust of his 

 hearer. It was by mere accident that an allusion was made to che- 

 mistry, when Davy flippantly observed, that he would undertake to demo- 

 lish the French theory in half an hour. He had touched the chord ; the 

 interest of Mr. Watt was excited ; he conversed with Davy on his che- 

 mical pursuits, and was at once astonished and delighted at his sagacity 

 the barrier of ice was broken, and they became attached friends.' 



Mr. Josiah and Mr. Thomas Wedgwood also spent a winter at 

 Penzance ; and Dr. Paris says he has reason to believe their friend- 

 ship was of substantial benefit to Davy. 



Upon the establishment of the * Pneumatic Institution ' at 

 Bristol, for the purpose of investigating the medical power of gases, 

 Dr. Beddoes required an assistant, and Mr. Gilbert recommended 

 Davy. Dr. Beddoes was acquainted with his experiments upon 



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