242 



oeings. It is a sad miscarriage of the powers of human reason, 

 when those who have laboured most assiduously in unravelling 

 the higher mysteries of physical causation are not thereby 

 brought nearer to their Creator, that : — 



" Those earthly godfathers of heaven's lights, 

 That give a name to every fixed star, 

 Have no more profit of those shining lights 



Than those who walk, and wot not what they are." 



61. The bearings of Evolution, Conservation, and Continuity 

 on the higher relations of man to his Creator must be left for a 

 future communication, to which the title of Scientific 

 Materialism may be not inappropriately applied. 



The Chairman. — It is now my duty to move that the thanks of this 

 meeting be given to Mr. Brooke for his very able and scientific paper. 

 Certainly, if Mr. Brooke and the discussion, which is now about to take 

 place, can do anything to remedy the " confusion worse confounded," which 

 at present pervades the scientific and philosophical world in regard to the use 

 of the terms " force " and " energy," a great deal of good will be done, for I 

 confess that as matters stand at present, I never hear the words used without 

 finding that there is a great amount of confusion and uncertainty in their 

 application. I may mention that strangers who desire to do so are invited 

 to take part in the discussion ; but as, to-night, there happens to be present 

 one who is pointedly referred to in ]\Ir. Brooke's paper, I think I shall con- 

 sult the feelings of the meeting if I ask him to open the debate, after our 

 Honorary Secretary has read a written communication from Dr. M'Cann. 



Captain F. Petrie then read Dr. M'Cann's communication as follows : — 



1 AM glad to find that Mr. Brooke agrees wdth me in my condemnation of 

 the way in which physicists, for the most part, speak of force, energy, and 

 motion. As he also differs very much from the theories of Professor Tyndall, 

 and the other physicists I have quoted, and has only taken up and fully 

 discussed the statements in §§ 59 to 61 of my paper, there are, consequently, 

 only a few points which I have to notice in his valuable essay. 



Conservation of energy, if limited by an Almighty will, need not, I grant, 

 lead to the results I have named ; but if unlimited, or actually conserved, 

 these results seem a necessary sequence, as is evidenced in my references to 

 those who affirm the existence of these results. 



He states (§ 14) that " the theory of the conservation of energy implies that 

 no kind of energy can be produced by human agency, except at the expense 

 of an equal amount of the same kind, or an equivalent amount of some other 

 kind of energy." From this it surely follows, in opposition to his next sen- 

 tence, that the total amount of energy in the universe remains not only 

 unchanged, but unchangeable ; which is the usual meaning of the theory, 

 although apparently not that held by Mr. Brooke. If the total amount of 

 energy be changeable, ought not the words to be that " no kind of energy is 

 produced ? " The corollary of this view of conservation, is the truism con- 

 demned by Sir John Herschel, for if an energy that is not kinetic is potential, 

 it is at once evident that the sum of both must be always equal. In § 29 

 we are told that "light and heat have frequently been illogically designated 

 by able physicists aimply as ' modes of motion.' This appears to have led 



