144 SOME OF THE LATSST ACHIEVEMENTS OF SCIENCE. 



gaseous — are due to molecules in a state of motion. Therefore matter 

 as we know it involves essentially a mode of motion, and the atom 

 itself — intangible, invisible, and inconceivable — is its material basis, 

 and may. indeed, be styled the only true matter. The space involved 

 in the motions of atoms has no more pretension to be called matter 

 than the sphere of influence of a body of riflemen — the sphere filled 

 with flying- leaden missiles — has to be called lead. Since what we call 

 matter essentially involves a mode of motion, and since at the tempera- 

 ture of absolute zero all atomic motions would stop, it follows that 

 matter as we know it would at that j)ai'alyzing- temperature pro])a])ly 

 entirel}^ change its properties. Although a discussion of the ultimate 

 absolute properties of matter is purely speculative, it (;an hardly be 

 barren, considering that in our laboratories we are now within mod- 

 erate distance of the absolute zero of temperature. 



I have dwelt on the value and importance of nitrogen, but 1 must 

 not omit to bring to your notice those little-known and curiously 

 related elements which during the past twelve months have been dis- 

 covered and partly descrilied by Professor Ramsay and Dr. Travers. 

 For many years my own work has been among what I may call the 

 waste heaps of the mineral elements. Professor Ramsay is dealing 

 with vagrant atoms of an astral nature. During the course of the 

 present year he has announced the existence of no fewer than three 

 new gases — krypton, neon, and metjirgon. Whether these gases, 

 chiefly known by their spectra, are true unalterable elements, or 

 whether the}' are compounded of other known or unknown bodies, has 

 3'et to be proved. Fellow-workers freely pay tribute to the painstak- 

 ing zeal with which Professor Ramsaj^has conducted a difficult research 

 and to the philosophic subtiet}^ brought to bear on his investigations. 

 But, like most discoverers, he has not escaped the flail of severe 

 criticism. 



There is still another claimant for celestial honors. Professor Nasini 

 tells us ho has discovered, in some volcanic gases at Pozzuoli, that 

 hypothetical element, coronium, supposed to cause the bright line 

 5316.9 in the spectrum of the sun's corona. Analogy points to its 

 being lighter and more diffusible than hydrogen, and a study of its 

 properties can not fail to yield striking results. Still awaiting dis- 

 cover}^ by the fortunate spectroscopist are the unknown celestial ele- 

 ments, aurorium. with a characteristic line at 5570.7, and nebulum, 

 having two bright lines at 5007.05 and 4959.02. 



The fundamental discover}' by Hertz of the electromagnetic waves 

 predicted more than thirty years ago by Clerk Maxwell seems likely 

 to develop in the direction of a practical application which excites 

 keen interest^I mean the application to electric signaling across mod- 

 erate distances without connecting wires. The feasibility of this 

 method of signaling has been demonstrated by several experimenters at 



