BY THE PEESIDENT. 51 



gradually cooling he could never get hot again. One fact seems 

 to favour the Nebular Theory, which the Germans call the 

 Kosmic-gas Theory, which is, that the earth seems to get hotter 

 the further "we descend into the interior ; and it is calculated that 

 if the heat increases in the same proportion, the interior of the 

 earth must he molten from heat. I do not think that the interior 

 of the earth is in a state of fusion from heat, and if it is so, a 

 different explanation may be given. But supposing that future 

 investigation should favour the truth of the Kosmic-gas Theory, 

 it would only be one link in the chain of ci'eation. If the solar 

 system arose from a state of nebula, it will, according to the theory 

 I am about to bring forward, again return to that state. 



As I shall have to use the words matter and force, it will be 

 well to explain what I mean by these terms. By matter I mean 

 whatever I can become acquainted with by means of my five 

 senses. I can feel this table, I can hear, smell, see, and taste. If 

 this definition is accepted, it will be seen that matter is divided 

 into two very distinct classes — firstly, things that can be Aveighed ; 

 secondly, things that cannot be weighed. I can weigh the table, 

 but I cannot weigh sound, or light, or thought, or magnetism, or 

 chemical force, or vital force. Although I believe that the im- 

 ponderable forces are really material, yet for convenience of lan- 

 guage we will still call them force or energy, and ponderable 

 matter simply matter. Only it is well to bear in mind that the 

 force of light, or heat, or electricity, is, in fact, as real a thing 

 as a ton of Hertfordshire conglomerate. Matter and force are in- 

 dispensable to each other ; it is impossible to imagine matter 

 without force, and it is difficult to imagine force without matter. 

 Porce is the active part of nature, matter is the passive. Force is 

 by far the most important of the two, besides, it is much greater 

 in extent. Matter occupies mere specks in space ; force fills the 

 immense intervals, and besides this, it penetrates, saturates, and 

 animates all matter. In order to understand the theory which I 

 wish to bring before you, it is desirable to bear in mind some of 

 the laws of matter and force. They both agree in this property — 

 they are indestructible. But they diifcr in this, that whereas 

 force is correlative, or one form of force may pass into another 

 form, yet with ponderable matter it is not so. We cannot change 

 one element of matter into another. Matter and force, if once set 

 in motion, must continue in motion for ever. The most important 

 property of matter and force is that they are always in motion. 

 Rest does not exist in nature. " Motion is the law of nature ; it 

 is only rest that is abnormal." Now if matter is endued with 



