266 MEMORIAL OF JOSEPH HENRY. 



In 1846, he presented to the Philosophical Society an epitome of 

 his views on the molecular constitution of matter; giving the 

 reasons for accepting the atomic hypothesis of Newton. He pointed 

 out that the discovery and establishment of a general scientific prin- 

 ciple "is in almost all cases the result of deductions from a rational 

 antecedent hypothesis, the product of the imagination ; founded it 

 is true on a clear analogy with modes of physical action, the truth 

 of which has been established by previous investigation :" and he 

 urged that the hope of further advancement lies in the assumption 

 " that the same laws of force and motion which govern the phenomena 

 of the action of matter in masses, pertains to the minutest atoms of 

 these masses." He therefore felt " obliged to assume the existence 

 of an setherial medium formed of atoms which are endowed with 

 precisely the same properties as those we have assigned to common 

 matter." 



"According to the foregoing rules we may assume with NewtOn, 

 the existence of one kind of matter diffused throughout all space, 

 and existing in four states, namely the setherial, the aeriform, the 

 liquid, and the solid." * [In referring to this postulated fourfold 

 state of matter, Henry was accustomed to point out the remarkable 

 analogy between this conception, and that of the four elements of 

 the ancients, fire, air, water, and earth.] 



"In conclusion, it should be remembered that the legitimate use of 

 speculations of this kind, is not to furnish plausible explanations 

 of known phenomena, or to present old knowledge in a new and 

 more imposing dress, but to serve the higher purpose of suggesting 

 new experiments and new phenomena, and thus to assist in enlarg- 

 ing the bounds of science, and extending the power of mind over 

 matter; and unless the hypothesis can be employed in this way, 

 however much ingenuity may have been expended in its construc- 

 tion, it can only be considered as a scientific romance worse than 



molecules are closer together. Of the nature of that "lateral adhesion" which resists 

 the flow of solids (excepting under the conditions of great strain long continued), 

 and whose absence is marked in liquids by their almost perfect and frictionless mo- 

 bility, our present science affords us no intimation. 



*T\yo hundred years ago, NEWTON speculating on the unity of matter, ventured 

 the suggestion, "Thus perhaps may all things be originated from aether." Letter to 

 the Secretary of the Royal Society Henry Oldenburg, January, 1676. (History of 

 the Royal Society : by Thomas Birch, vol. iii. p. 250. ) 



