October 14, 1898.] 



SCmNGE. 



493 



with a great many specimens, obtained in 

 various ways from various sources, but al- 

 ways mixed with a very large excess of 

 other gases. Some specimens were almost 

 wholly absorbed by the phosphorus pen- 

 toxide at first used for desiccation. Others 

 were but partially absorbed ; the absorption 

 being very rapid at first, but in an hour or 

 two dwindling to nothing, and leaving a 

 residue of gases permanently showing, by 

 their heat conductivity, the presence of a 

 very considerable amount of etherion. 

 Soda-lime absorbed etherion, but much less 

 freely than phosphorus pentoxide, and gave 

 it up again on heating. The gas thus re- 

 covered was but little, if at all, affected by 

 phosphorus pentoxide. 



In one experiment the gases evolved 

 from ten ounces of pulverized window glass, 

 both before and after heating, were passed 

 through coarsely pulverized soda-lime and 

 then over fresh phosphorus pentoxide. Not 

 a trace of etherion remained. Tbe same 

 result was obtained when another lot of the 

 silicious sand, already referred to, was used 

 as the source of etherion. 



I will venture the conjecture that etherion 

 will be found to consist of a mixture of three 

 or more gases, forming one or more pei'iodic 

 groups of new elements, all very much 

 lighter than hydrogen. If this proves true 

 I propose to retain the present name for 

 the lightest one. 



The transmission of radiant energy 

 through space has always been to me a 

 fascinating phenomenon, and I have in- 

 dulged in much speculation concerning the 

 ether — that mysterious something by means 

 of which it is effected. The remarkable 

 properties assigned to the ether from time 

 to time, in order to account for observed 

 phenomena, have excited my keen interest; 

 but I have long entertained the hope that 

 some simpler explanation of the mechanism 

 involved will be found. To me, a less 

 strain of the imagination is req^uired in the 



assumption that, instead of a continuous 

 medium, gaseous molecules of some kind, 

 endowed perhaps with a mode or modes of 

 motion at present unknown to us, are the 

 agent of transmission; a gas so subtle, and 

 existing everywhere in such small quantity, 

 that it has escaped detection. 



Perhaps the molecular hypothesis of the 

 ether has proved so attractive to me be- 

 cause it supports the hope that we may 

 sometime compass the perfect vacuum — a 

 portion of space devoid of everything. Such 

 a vacuum would be opaque to light, and 

 gravitative attraction could not, I believe, 

 act through it. It might afford a new 

 point of view from which to study the pro- 

 found mystery of gravitation ; an outside 

 point. 



The late De Volson Wood (Phil. Mag., 

 Nov., 1885) considered the question of a 

 gaseous ether mathematically, and deduced 

 certain necessary properties of the hypo- 

 thetical gas ; chief among which were ex- 

 ceedingly small density and exceedingly 

 high specific heat. Possibly we are about 

 to find a gas which will fulfil the required 

 conditions. It may be etherion, or its 

 lightest constituent if it turns out to be a 

 mixture. I venture to express the hope 

 that etherion will at least account for some 

 phenomena at present attributed to the 

 ether. 



On account of the presumably extreme 

 smallness of its molecules as compared with 

 those of glass, etherion probably passes 

 through the latter when any considerable 

 difference of pressure exists on opposite 

 sides ; though the passage may be very slow. 

 It seems to be condensed or compressed in 

 glass as before indicated, and may evapo- 

 rate on the side of lower pressure, and be 

 absorbed on the side of higher pressure, 

 after the manner of hydrogen in passing 

 through palladium. In my own experi- 

 ments the heat transmission ascribed to the 

 ether may be due to the presence of the new 



