104 THE ROYAL INSTITUTION. [CHAP. II. 



being perfectly free and unconditional, and that yon would 

 enjoy and dispose of what is now your property just as you 

 shall think best and most conducive to your happiness and 

 to your satisfaction, without any regard to any former 

 arrangements you have made at my request. 



My health continues to be good, and I yet feel none of 

 those infirmities of age which sometimes render the evening 

 of life painful. I have the satisfaction to think that I have 

 done my duty through life, and that is a great consolation 

 to me as I approach the end of my course. I shall never 

 cease to be, my dear mother, your dutiful and affectionate 

 child, 



BENJAMIN. 



On January 23 he had a paper read before the 

 Royal Society which he published as his seventeenth 

 essay. It was an ' Inquiry Concerning the Source of 

 the Light which is Manifested in the Combustion of 

 Inflammable Bodies.' 



His object was to prove by decisive experiments 

 that the light which accompanies the complete com- 

 bustion of any given quantity of pure inflammable 

 matter is variable, and therefore light cannot be one 

 of the chemical products of combustion. 



If light were a substance, as has been supposed, it seems 

 highly probable that means would long since have been 

 found to discover where and how it exists ; but if it be 

 nothing more than a blow given to the eye by the 

 repercussion of an ethereal fluid which touches that organ 

 and at the same time every other body in the universe, it is 

 evident that all attempts to discover it in a state of com- 

 bination must be vain. 



Nobody, I imagine, ever thought of searching for sound 

 in a fulminating powder. Is it more reasonable to search 

 -there for the light that accompanies the combustion of sub- 

 stances ? 



