658 ADDRESS OF PROFESSOR LOVERING. 
which held them. The discovery that heat was a motion and not 
a substance, foreshadowed by Bacon, made probable by Rumford 
and Davy, and rigidly proved by Mayer and Joule when they ob- 
tained its exact mechanical equivalent, opened the way to the 
dynamical theory of gases. Joule calculated the velocity of this 
promiscuous artillery, rendered harmless by the minuteness of the 
missiles, and found that the boasted guns of modern warfare could 
not compete with it. Clausius consummated the kinetic theory of 
gases by his powerful mathematics, and derived from it the exper- 
imental laws of Mariotte, Gay-Lussac and Charles. By the as- 
sumption of data, more or less plausible, several mathematicians 
have succeeded in computing the sizes and the masses of the mol- 
ecules and some of the elements of their motion. It should not 
be forgotten that mathematical analysis is only a rigid system of 
logic by which wrong premises conduct the more surely to an in- 
correct conclusion. To claim for all the conclusions which have 
been published in relation to the molecules the certainty which 
fairly belongs to some of them would prejudice the whole cause. 
One of the most interesting investigations in molecular me 
chanics was published by Helmholtz in 1858. It is a mathemati- 
cal discussion of what he calls ring-vortices in a perfect, friction- 
less fluid. Helmholtz has demonstrated that such vortices possess 
a perpetuity and an inviolability once thought to be realized only 
‘by the eternal atoms. The ring-vortices may hustle one another, 
d 
and pass through endless transformations, but they cannot be 
broken or stopped. Thomson seized upon them as the imperson- 
ation of the indestructible but plastic molecule which he was 
looking for, to satisfy the present condition of physical papes 
The element of the new physics is not an atom or a congeries of 
atoms but a whirling vapor. The molecules of the same substance 
have one invariable and unchangeable mass: they are all tuned to 
one standard pitch and, when incandescent, emit the same kind of 
light. The music of the spheres has left the heavens and conde- 
scended to the rhythmic molecules. There is here no bir 
or variation of species. If other masses than the precise ones 
represent the elements have been eliminated, where, asks #8 
well, have they gone? The spectroscope does not show them 5 
the stars or nebulæ. The hydrogen and sodium of remotest space 
are in unison with the hydrogen and sodium of earth. 
In the phraseology of our mechanics we define matter and fore? 
th or death 
which 
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