October 23, 1903.] 



SCIENCE. 



527 



growth of the elements; do we, in the phe- 

 nomena of radio-activity, witness their de- 

 cay? This is a startling;, possibly a rash 

 speculation, but it rests upon evidence 

 which must be considered and weighed. 



We have, then, various lines of converg- 

 ent testimony, and there are more which I 

 might have cited, all pointing to the con- 

 clusion that the chemical atoms are com- 

 plex, and that elemental matter, in the last 

 analysis, is not of many kinds. That 

 there is but one fundamental substance, is 

 not proved; and yet the probability in 

 favor of such an assumption must be con- 

 ceded. Assuming it to be true, what then 

 is the nature of the Daltonian atom ? 



To the chemist, the simplest answer to 

 this question is that furnished by the re- 

 searches of J. J. Thomson, to w-hieli refer- 

 ence has already been made. A cluster of 

 smaller particles or corpuscles satisfies the 

 conditions that chemistry imposes on the 

 problem, their ultimate nature being left 

 out of account. For chemical purposes we 

 need not inquire whether the corpuscles 

 arc divisible or indivisible, although for 

 other lines of investigation this question 

 may be pertinent. But no matter how far 

 we may push our analysis, we must always 

 see that something still lies beyond us, and 

 realize that nature has no assignable boun- 

 daries. That which philosophers call 'the 

 absolute' or 'the unconditioned' is forever 

 out of our reach. 



Through many theories men have sought 

 to get back a little farther. Among these. 

 Lord Kelvin's theory of vortex atoms is 

 perhaps the most conspicuous, and cei'- 

 tainly the best known. It presupposes an 

 ideal perfect fluid, continuous, homogene- 

 ous and incompres-sible ; portions of this in 

 rotation form the vortex rings, which, when 

 once set in motion by some creative power, 

 move on indestructibly forever. These 

 rings may be single, or linked or knotted 



together, and they are the material atoms. 

 The assumed permanence of the atom is 

 thus accounted for and given at least a 

 mathematical validity, but we have already 

 seen that the chemical units- may not be 

 quite so simple. The ultimate corpuscles, 

 to use J. J. Thomson's words, may be vor- 

 tex rings ; the chemical atom is much more 

 complex. On this theory, chemical union 

 has been explained by supposing that vor- 

 tices are assembled in rotation about one 

 another, forming groups which are per- 

 manent under certain conditions and yet 

 are capable of being broken down. The 

 vortex ring is eternal, its groupings are 

 transitory. This is a plausible and fasci- 

 nating theory ; if only we can imagine the 

 ideal perfect fluid and apply to it the laws 

 of motion; that done, all else follows. 

 Unfortunately, however, the fundamental 

 conception is difficult to grasp and still 

 more difficult to apply. So far, it has 

 done little or nothing for chemistry; it 

 has brought forth no discoveries, nor stim- 

 ulated chemical research; we can only say 

 that it does not seem to be incompatible 

 with what we think we know. In a certain 

 way it unifies the two opposing concep- 

 tions of atomism and plenism, and this may 

 be, after all, its chief merit. 



But there are later theories than that of 

 Kelvin, and some of them are most daring. 

 For instance. Professor Larmor regards 

 electricity as atomic in its nature, and sup- 

 poses that there are two kinds of atoms, 

 positive and negative electrons. These 

 electrons are regarded as centers of strain 

 in the ether, and matter is thoiight to con- 

 sist of clusters of electrons in orbital mo- 

 tion round one another. Still more re- 

 cently. Professor Osborne Reynolds, in his 

 Rede lecture,* has offered us an even more 



* ' On an Inversion of Ideas as to the Structure 

 of the Universe.' Cambridge, 1903. The Rede 

 Lecture, delivered .June 10, 1902. 



