A MODEL OF NATURE. 



Bv Arthur W. Rucker, M. A.. LL.D. 



* * * Two years ag-o Sir jMiehael Foster dealt with the work of 

 the century as a whole. Last year Sir William Turner diseussed in 

 greater detail the growth of a single branch of science. A third 

 and humbler task remains, viz, to fix our attention on some of the 

 h3'potheses and assumptions on which the fabric of modern theo- 

 retical science has been built, and to inquire whether the foundations 

 have been so "'well and truly" laid that they may })e trusted to sustain 

 the might}' superstructure which is being raised upon them. 



The moment is opportune. The three chief conceptions which for 

 many years have dominated ph3\sical as distinct from biological science 

 have been the theories of the existence of atoms, of the mechanical 

 nature of heat, and of the existence of the ether. 



Dalton's atomic theor}' was first given to the world })y a Glasgow 

 professor — Thomas Thomson — in the year 1807, Dalton having com- 

 municated it to him in 1804. Rumford's and Davy's experiments on 

 the nature of heat were published in 1798 and 1799, respectively; and 

 the celebrated Bakerian lecture, in which Thomas Young established 

 the undulatory theory by explaining the interference of light, 

 appeared in the Philosophical Transactions in 1801. The keynotes of 

 the physical science of the nineteenth century were thus struck as the 

 century ])egan ))}' four of our fellow-countrymen, one of whom — Sir 

 Benjamin Thompson, Count Rumford — preferred exile from the land 

 of his birth to the loss of his birthright as a British citizen. 



DOUBTS AS TO SCIENTIFIC THEORIES. 



It is well known that of late doubts have arisen as to whether the 

 atomic theory, with Avhich the mechanical theory of heat is closely 

 bound up, and the theor}' of the existence of an ether have not served 

 their purpose, and whether the time has not come to reconsider them. 



The facts that Professor Poincare, addressing a congress of physi- 

 cists in Paris, and Professor Poynting, addressing the physical section 



"Address of the President of the British Association for the Advancement of 

 Science, at the Glasgow meeting, 1901. Reprinted from Report of the British Asso- 

 ciation, 1901. 



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