THE MYSTERY OF MATTER. 



179 



extreme rapidity, the velocity of motion increasing as the 

 temperature rises. We also note that in solid bodies the molecules 

 are comparatively close together and their sphere of motion is 

 limited ; that in liquids they move amongst each other to some 

 extent and their sphere of motion is increased; and that in 

 gases the molecules are very much further apart, and their rate 

 of motion becomes very much more rapid, while they dash 

 amongst each other in all directions, constantly striking against 

 each other and against the walls of any vessel containing them. 

 We must also bear in mind that the intramolecular motion 

 of the atoms becomes greatly accelerated in gases. 



Until very recently it was almost universally believed that 

 atoms were simple and indivisible specks of matter. 



Soon after the time of Dalton, early in the 19th century, 

 it was noticed that the atomic weights of most of the elementary 

 bodies were very nearly exact multiples of the weight of the 

 atom of hydrogen, the element which has the lowest atomic 

 weight. And Prout tried to show that hydrogen was really the 

 primordial substance which lay at the root of all matter, and 

 that all the various elements really consisted of different 

 combinations of the hydrogen atom. This view was also 

 .supported by Dimias the celebrated French chemist. It was 

 soon shown, however, by more accurate detenninations, that the 

 atomic weights of very few of the elements were anything like 

 exact multiples of the atomic weight of hydrogen, and tliis 

 hypothesis necessarily fell to the ground. Professor Wurtz, of 

 Paris, some 30 years ago or more, suggested that possibly the 

 hydrogen atom was composed of about ten or more sub-atoms ; 

 and that these sub-atoms by different combinations and in 

 varying proportions built up the atoms of all the other elements ; 

 so that we might look upon all matter as fundamentally the 

 same, the different atoms being all composed and made up of 

 sub-atoms exactly similar to each other. 



But recent discoveries have revealed to us that matter is very 

 much more complex still, and in the light of the present day we 

 have learned not only that atoms can no longer be looked upon 

 as indivisible, but that, on the contrary, each atom is built up of 

 thousands of still more minute particles. We have also found 

 that atoms are not indestructible, for it has been shown that the 

 atoms of at least some elements may undergo dissolution, and 

 that the sub-atoms and particles which they contain may enter 

 into new combinations, and build up new atoms of entirely 

 different elements. Thus the leading idea of the old Alchemists 



