304 Existence of a new Element, probably of the Sulphur Group. 
apparatus by myself and many friends. Not a trace of such a line 
is shown by either of them in the green part of the spectrum,— 
Antimony, arsenic, and osmium, in fact, giving continuous spectra, 
in which every colour is visible. The remaining elements, sele- 
nium and tellurium, might almost be dismissed unchallenged, 
inasmuch as I was first led to the examination by finding that it 
was not either of these. Nevertheless I have, as stated at the 
commencement of this paper, repeatedly examined their spectra, 
and find no trace of such a line, the alternate light and dark 
bands in the almost continuous spectra of selenium and tellurium 
forming in fact so strong a contrast to the one single green ray 
of the new substance, that the latter may readily be detected in 
the presence of an enormous excess of either of the former. 
In order to remove any remaining doubt which there might 
be as to the green line being due to any of the elements men- 
tioned in the above list, I have, moreover, specially examined the 
spectra produced by each of these bodies in detail, either in their 
elementary state, or in their most important compounds. Many 
of them give rise to spectra of great and characteristic beauty, 
but none give anything like the green line; nor, in fact, is there 
any artificial spectrum, except that of sodium, which equals it in 
simplicity. 
There still may be urged the possibility of its being a compound 
of two or more known elements, or an allotropic condition of one 
of them ; a moment’s thought, however, will show that neither of 
these hypotheses is tenable. They would in reality prove what 
they are raised to oppose; for nothing less could follow than a 
veritable transmutation of one body into another, and a conse- 
quent annilulation of all the groundwork upon which modern 
science is based. If an element can be sochanged as to have 
totally different chemical reactions, and to have the spectrum of 
its incandescent vapour (which is, par excellence, an elementary 
property) altered to an appearance totally unlike that given by 
its former self, it must have been changed into something which 
it originally was not. ‘This, in the present position of science, is 
an absurdity. 
The method of exhaustion which I have adopted to prove 
the elementary character of the body which communicates this 
green line to the spectrum of the blue gas-flame*, may seem 
unnecessary as well as unchemical in the present state of the 
science ; I was obliged, however, to rely upon what I may call 
circumstantial evidence of its not being a known element, 
owing to the very small quantity of substance at my command 
* TI need scarcely add that the line is quite distinct from either of the 
green or blue lines seen in a gas-flame which is undergoing complete com- 
bustion. It is moreover far more brilliant than these. 
