1883.] on Count Bumford, Originator of the Boyal Institution. 447 



Lis reasoning has not the remotest application, which, like water, 

 expand before and during crystallisation. The conditions necessary 

 to the life of our planet must have existed before life appeared ; but 

 whether those conditions had prospective reference to life, or whether 

 its immanent energy did not seize upon conditions which grew into 

 being without any reference to life, we do not know ; and it would be 

 mere arrogance at the present day to dogmatise upon the subject. 



In the controversy whether heat was a form of matter or a form 

 of motion, Rumford espoused the latter view. Now those who sup- 

 posed heat to be matter naturally thought that it might be ponder- 

 able, and experiments favourable to this notion had been executed. 

 Operating with a balance of extreme delicacy, Rumford took up this 

 question, and treated it with great skill and caution. His conclusion 

 from his experiments was that, if heat be a substance — a fluid sui 

 generis — it must be something so infinitely rare, even in its condensed 

 state, as to baffle all our attempts to discover its gravity. But " if the 

 opinion which has been adopted by many of our ablest philosophers, 

 that heat is an intestine vibratory motion of the constituent parts of 

 bodies, should be well founded, it is clear that the weights of bodies 

 can be in no wise affected by such motion." The weight of a bell, he 

 urges in another place, is not affected by its sonorous vibration. 



Early in the year 1803, he being then in Munich, Rumford broke 

 ground in the domain of radiant heat. He prepared bright metallic 

 vessels, filled them with hot water, placed them in a large and quiet 

 room, and observed the time required to cool them down a certain 

 number of degrees. Covering some of his vessels with Irish linen 

 and leaving others bare, he found, to his surprise, that the covered 

 vessels were more rapidly chilled than the naked ones. Comparing 

 in the same room a thick glass bottle, filled with hot water, with a tin 

 bottle of the same shajDC and size, he found that the water in the glass 

 vessel cooled twice as rapidly as that in the tin one. When, moreover, 

 he coated his metallic vessel with glue, the cooling process was hastened, 

 as it had been by the linen. Appl.ying a second, a third, and a fourth 

 coating of glue, he found the chilling promoted ; but beyond this he 

 came to a point where the addition of any further coatings produced 

 a retardation of the chilling. Painting some of his vessels black and 

 some white, he found the times of cooling to be practically the same 

 for both — a result which he seems to have afterwards forgotten. 

 From these and other experiments of the same kind he drew the just 

 conclusion that a hot body does not lose its heat by the mere com- 

 munication of it to the ail', but that a large proportion of the heat 

 escapes in rays, the escape being facilitated by the substances with 

 which his vessels were coated. The more rapid chilling of the glass 

 bottle was due, in like manner, to the fact that glass possesses a 

 greater radiative j)Ower than tin. 



He next applies himself with energy, zeal, and tenacity, to prove 

 that there are frigorific rays which act in all respects like calorific 

 rays, and which enjoy an individuality quite as assured as that of the 



