Qc ill 



ON 



RADIANT MATTER. 



throw light on the title of this lecture I must go back 

 more than sixty years to 1816. Faraday, then a 

 mere student and ardent experimentalist, was 24 years 

 old, and at this early period of his career he delivered a 

 series of lectures on the General Properties of Matter, 

 and one of them bore the remarkable title, On Radiant 

 Matter. The great philosopher's notes of this lecture are to 

 be found in Dr. Bence Jones's Life and Letters of Faraday, 

 and I will here quote a passage in which he first employs 

 the expression Radiant Matter : 



" If we conceive a change as far beyond vaporisation as that is above 

 fluidity, and then take into account also the proportional increased 

 extent of alteration as the changes rise, we shall perhaps, if we can 

 form any conception at all, not fall far short of Radiant Matter ; and 

 as in the last conversion many qualities were lost, so here also many 

 more would disappear." 



Faraday was evidently engrossed with this far-reaching 

 speculation, for three years later in 1819 we find him 

 bringing fresh evidence and argument to strengthen his 

 startling hypothesis. His notes are now more extended, and 

 they show that in the intervening three years he had thought 

 much and deeply on this higher form of matter. He first 

 points out that matter may be classed into four states solid, 

 liquid, gaseous, and radiant these modifications depending 

 upon differences in their several essential properties. He 

 admits that the existence of Radiant Matter is as yet un- 

 proved, and then proceeds, in a series of ingenious analogical 

 arguments, to show the probability of its existence.* 



* " I may now notice a curious progression in physical properties ac- 

 companying changes of form, and which is perhaps sufficient to induce, 

 in the inventive and sanguine philosopher, a considerable degree of 



216 B * 



