as mem en sia forjxetajxo de sekvanteroj.

Eble estas permeseble konjekti ke elektronoj estas malgrandaj, kaj
atomoj de heliumo pli grandaj sekvanteroj. Sed preterdauxrigi la
temon, sen difina konigxo, kiu nur povas ricevigxi per eksperimentoj,
estus malutile.

Kompreneble multe da laborantoj, kiel eble plej ili povas, en la nuna
tempo penadas por enigxi pli profunde en tiujn interesegajn regionojn
de esplorado.

RADIUM.

_By_ Sir William Ramsay, K.C.B., F.R.S.

The strange qualities of radium, especially its brilliance in the
dark and its power of illuminating some other bodies, attracts the
attention of the entire world. This radium is, we believe, a metal,
although till now it has not been produced in metallic form, for its
salts are similar to the salts of barium, a white metal and a
well-known element. The reason is that so little of these salts is
available that it cannot be wasted in experimenting to effect the
change from a salt into a metal, for the loss would be great. The
best-known salt, the bromide, costs twelve shillings per milligram,
an almost invisible quantity.

All metals have their peculiar spectra. If their salts be heated in a
flame, on examining them by means of the spectroscope, coloured lines
peculiar to each metal may be seen, which are named its "spectrum."
Thus a metal is recognisable from its spectrum. Radium has its
particular spectrum, which is like the spectrum of barium, but
different in the location of the lines. We therefore believe that
radium is an element similar to the other metals.

From the salts of radium a gas continually escapes, which has the
quality of shining in the dark, remaining warm the while, and it
throws out bodies known as electrons. When these bodies touch the air
or any gas they impart to that gas the power to discharge an
electroscope. While this gas is giving forth heat and discharging
electrons it gradually vanishes, and instead another gas appears, of
low density, the spectrum of which M. Janssen, a famous French
astronomer, noticed in the light of the sun during 1868, and which
was first discovered on the earth by the writer of this article.

It seems, therefore, that one element, radium, can produce
another--namely, helium. Whether, as is possible, other elements are
formed at the same time we do not know. That question remains for
further investigation.

Let us see whether radium possesses any properties, differing in kind
or in degree, f