268 THE POPULAR SCIENCE MONTHLY. 



who are so anxious to subordinate, if not wholly lay down, the gentle 

 functions of maternity in order that they may engage in the sterner 

 work of the world ! 



When, marking their size, we consider the mighty character of the 

 works which they complete ; when we reflect upon the infinitesimal 

 ganglion which is the seat of the intelligence they display, we may 

 well be filled with surprise, and almost wonder if man, or any other 

 order of the vertebrata, is destined to remain forever the higher 

 animal ! 



THE FIEST AND THE LAST CATASTKOPHE. 



By W. KINGDON CLIFFOED, 

 pkofessoe in the itniveesity of londox, 



I PROPOSE in this lecture to consider speculations of quite recent 

 days about the beginning and the end of the world. The world 

 is a very interesting thing, and I suppose that from the earliest times 

 that men began to form any coherent idea of it at all, they began to 

 guess in some way or other how it was that it all- began, and how it 

 was all going to end. But there is one peculiarity about these spec- 

 ulations which I wish now to consider, that makes them quite differ- 

 ent from the early guesses of which we read in many ancient books. 

 These modern speculations are attempts to find out how things began, 

 and how they are to end, by consideration of the way in which they 

 are going on now. And it is just that character of these speculations 

 that gives them their interest for you and for me ; for we have only 

 to consider these questions from the scientific point of view. By the 

 scientific point of view, I mean one which attempts to apply past 

 experience to new circumstances according to an observed order of 

 Nature. So that we shall only ponsider the way in which things 

 began, and the way in which they are to end, in so far as we seem 

 able to draw inferences about those questions from facts which we 

 know about the way in which things are going on now. And, in 

 fact, the great interest of the subject to me lies in the amount of 

 illustration which it offers of the degree of knowledge which we have 

 now attained of the way in which the universe is going on. 



The first of these speculations is one set forth by Prof. Clerk Max- 

 well, in a lecture on " Molecules," delivered before the British Asso- 

 ciation at Bradford. By a coincidence, which to me is a happy one, 

 at this moment Prof. Maxwell is lecturing to the Chemical Society 

 of London upon the evidences of the molecular constitution of matter. 

 Now, this argument of his, which he put before the British Associa- 

 tion at Bradford, depends entirely upon the modern theory of the 

 molecular constitution of matter. I think this the more important, 



