316 THE EOYAL INSTITUTION. [CHAP. VI. 



On July 3, 1800, Davy wrote from Bristol to Gilbert : 



We have been repeating the galvanic experiments with 

 success. Nicholson, by means of a hundred pieces of silver 

 and zinc, has procured a visible spark. Cruickshank has 

 revived oxidated metals in solution by means of the nascent 

 hydrogen produced from the decomposition of water by the 

 shock, and both he and Carlisle have absolutely resolved 

 water into oxygen and hydrogen by means of it, making 

 use of silver and platina wires. An immense field of 

 investigation seems opened by this discovery; may it be 

 pursued so as to acquaint us with some of the laws of 

 life! 



You have undoubtedly heard of Hersohel's discovery 

 concerning the production of heat by invisible rays 

 emitted from the sun ? 



Coleridge is gone to reside in Cumberland. 



Yours, with sincere affection, 



HUMPHEY DAVY. 



On October 20, 1800, again he wrote to Gilbert: 



In pursuing experiments on galvanism during the last 

 two months I have met with unexpected and unhoped-for 

 success. Some of the new facts on this subject promise to 

 afford instruments capable of destroying the mysterious veil 

 which nature has thrown over the operation and properties 

 of ethereal fluids. 



Galvanism I have found, by numerous experiments, to be 

 a process purely chemical. 



I remain, with sincere respect and affection, yours, 



HUMPHEY DAVY. 



During this year he published a volume entitled 

 'Researches, Chemical and Philosophical, chiefly con- 

 cerning Nitrous Oxide and its Kespiration,' 



