1879.1 "' [Chase. 



day recounts the experiments of an A.merican-born citizen, Benjamin 

 Thompson, commonly known as Count Rumford, together with subsequent 

 confirmatory experiments of remarkable nicety and remarkable fruitful- 

 ness, by Joule, Mayer, Colding, and others. Those experiments all point 

 to molecular motion as the source of heat, and their recognized importance 

 is so great that the new science of heat, or "thermodynamics," ranks as 

 one of the chief physical sciences. Some even go so far as to think it the 

 only physical science, or at least the fundamental science. The genial 

 glow of the hearth-fire may quicken the circulation ; the quickened circu- 

 lation may enliven the spirit; but the spiritual enlivenment and the pleas- 

 ant sensation of warmth by which it is accompanied are both very different 

 from motion, and from all other sensations. They are both realities of a 

 higher order than any mere physical fact ; realities that are only possible 

 in and through intelligence. 



The other tactile sensations as well as the renderings of the muscular 

 sense may be referred to various degrees of resistance, dependent upon the 

 aeriform, liquid or solid condition of the body which awakens the sensa- 

 tion. We have already seen that elasticity may be explained by motion, 

 and even the most solid bodies are often highly elastic. The advocates of 

 the atomic hypothesis commonly regard the ultimate atoms as very hard, 

 but the mathematical requirements of the relation between heat under con- 

 stant pressure and under constant volume point to great elasticity. The 

 new chemistry, and Lockyer's late spectroscopic discoveries, also have the 

 same ultimate pointing. They regard all the chemical elements as based 

 on the hydrogen atom, and it has been shown* that the elasticity of hj'dro- 

 gen is so simply related to the elasticity of the luminiferous aether that 

 hydrogen may be merely condensed aether. All the particles of steel 

 and platinum and of all other material substances are supposed to be in 

 endless motion, through orbits of minute extent which are traversed in 

 brief periods with great velocity. The resistance of such orbits to any 

 change of relative position increases in proportion to the square of the 

 velocity, so that any desired degree of rigidity might be obtained, without 

 any actual contact of particles, by simply giving them velocity enough. 

 The nervous action which is excited by the resistances of physical im» 

 penetrability, is transmitted to the brain, where it is received by conscious- 

 ness, not as motion ; not even as light, nor as sound, nor as taste, nor as 

 smell, nor as warmth, but simply as resistance ; a spiritual reality of a 

 higher order than anything which is merely material ; a reality which is 

 made by intelligence and which is lost as soon as intelligence ceases to 

 wield its upholding power. 



We thus see that the " evidence of the senses," so far from being a cor- 

 rect transcript of outward realities, is always as deceptive as the seeming 

 quiet of the seeming general flat terrestrial plane, and as the seeming daily 

 revolution of the sun and moon and stars around our seeming centre of the 

 universe. Our natural and irresistible conviction, that the senses report 



*Proc. Am. Phil. Soc, xii, 394; xiii, 142. 



PItOC. AMER. PHILOS. SOC. XVIII. 103. R. PRINTED FEB. 25, 1879. 



