[July 20, 1372. 
48 THE PHARMACEUTICAL JOURNAL ANT) TRANSACTIONS. 
Thus prior to the discovery of the first of the elemen¬ 
tary gases, twenty-three hinds of solid matter, and one 
liquid body, mercury, were known, which afterwards be¬ 
came recognized as elements. Between then and the present 
time, thirty-three kinds of solid matter, and one liquid 
body, bromine, have been added to the list—the discovery 
of the earliest of them occurring almost simultaneously 
with, or even just preceding, that of the last discovered 
of the elementary gases. 
Among the number of bodies discovered prior to 1803, 
when Davy effected the decomposition of the alkalies, 
several, at first thought to he elementary, are now known 
to he compounds of oxygen with other bodies still re¬ 
garded as elements ; and conversely, two bodies, namely, 
chlorine and fluorine, at one time thought to be oxides, 
have since become regarded as elementary ; but in none 
of these cases did the discovery of what is now considered 
to be the real constitution of the bodies add or subtract 
an element to or from the list. 
From the period of the modern or Lavoiserian con¬ 
ception of elements and compounds down to the begin¬ 
ning of the nineteenth century, the recognition of new 
elements occurred with much frequency, at short but 
varied intervals. After then, the discoveries became 
somewhat less frequent; but even within the last fifty 
years, no fewer than twelve now elements have been 
added to the list, being at the rate of one new element 
every four years. Throughout, the periods of discovery 
have been somewhat irregular in their occurrence. 
Thus in the years 1802 and 1S03, six new elements were 
discovered, namely tantalum, cerium, palladium, rhodium, 
iridium and osmium ; within the succeeding fourteen 
years only one new element, but that a very important 
one, namely, iodine; and in the fifteenth and sixteenth 
years, three new elements, namely, lithium, selenium 
and cadmium. The longest barren interval, one of 
thirteen years duration, took place between the discovery 
of niobium, by Rose, in 1816, and that of caesium and 
rubidium, by Bunsen, in 1859. The last discovered ; 
of the elements, namely indium, being fully seven years 
old, and there, being no reason to consider our present j 
list as anything like complete, or to apprehend any 
cessation of additions thereto, it is now quite time for i 
seme other new element to be made known. For we j 
may reasonably anticipate the discovery of new elements 
to take place at irregular intervals possibly for centuries 
to come, and our list of the elements to be increased at 
least as much in the luturo as in the past. 
The fresh discovery, however, of any abundant elemen- 
taiy constitutent of the earth’s crust would seem scarcely 
now to be cxpccte 1, s }eing that of the thirty-two elements 
which have become known since the year 1771,_the' 
yeai of the discovery of chlorine and oxygen and man¬ 
ganese and baryta, the great majority belong to the 
class of chemical curiosities; while even the° four or 
five most abundant of the since discovered elements are 
found to enjoy but a sparing although wide distribution 
m nature, as is the case, for example, with bromine 
and.iodine; or else, to be concentrated but in a few 
specially localized minerals, as is tlic case, for example 
with strontium and chromium and tungsten. Of course 
it is difficult to appraise the relative abundance in 
nature of different elements ; more especially from the 
circumstance of those which are put to commercial uses 
being everywhere sought for, and those not put to com¬ 
mercial uses being habitually neglected,—save indeed 
by the man of science, to whom the peculiar properties 
ot some of the less familiarly known elements, as‘palla¬ 
dium, osmium, erbium, didymium, uranium and thal¬ 
lium, render them objects of the highest interest. 
A \ erj. notable point with regard to the iast-discovered 
four . elements, namely, rubidium, caesium, thallium 
and mumm, i3 their successive discovery within a few 
years of each other, by one and the same process, namely, 
that of spectrum analysis. This process, invented and 
made available as a means of chemical research by 
Bunsen and .Kirchoffin 1856, consists simply in allowing 
the light given off by different ignited gases and vapours, 
limited by means of a fine slit, to pass through a prism 
or succession of prisms ; and in observing the so-pro¬ 
duced, brightly-coloured, widely extended image of th- 
slit. It has been known from the days of Newton, thae 
by the passage of heterogeneous light through a pris¬ 
matic highly dispersive medium, its differently refrant 
gible constituents become widely separated from each* 
other, so as to furnish an elongated coloured spectrum. 
But. whereas the spectra of incandescent solid and liquid 
bodies are continuous, and not distinctive of the particu¬ 
lar luminous bodies yielding them, the spectra of incan¬ 
descent. gaseous or vaporized bodies are found to be- 
discontinuous, and to consist of one or more bright lines 
of different colour, thickness and position, according to- 
the nature of the particular incandescent gases or vapours- 
from which the light through the slit is proceeding. 
In this way it is found that the spectra of the different 
chemical elements, alike when free and in combination, 
are perfectly definite, and characteristic of the particular 
elements vaporized and made incandescent. * And in many 
cases, the spectra or portions of the spectra of particular 
elements, even when present in the most minute pro¬ 
portion, are so extremely well marked and distinctive, 
that the presence or absence of these elements is deter¬ 
minable with the greatest case and certainty, by a mere 
inspection of the emission spectra yielded by the incan¬ 
descent gases or vapours under examination. Moreover, 
gases and vapours are further capable of affecting hetero¬ 
geneous light which is passed through them; and of 
thus yielding absorption spectra, in which the charac¬ 
teristic lines of the above-described emission spectra are 
reversed, so as to appear, unaltered in position, as black 
lines or intervals in an otherwise continuous band of 
colour. 
(To be continued.) 
A SIMPLE QUICKSILVER LUTE. 
BY H. KARST EX f 
In cases where tubes cannot be connected by india- 
rubber, corks, etc., the author makes a gas-tight junction 
by making the two tubes to be joined vertical, the lower 
one. capable of sliding within the other; when in this, 
position the open end of the upper or outer tube is sur¬ 
rounded by mercury retained by a cup, through the- 
bottom of which the smaller tube passes. The wholn 
apparatus is most easily constructed, and can readily be 
taken to pieces and put together again .—Journal of the 
Chemical Society. 
THE ACTION OF BONE CHARCOAL IN SUGAR 
MAKING. 
BY C. AVERXEKIXCK.j; 
The author, starting from previously known facts, 
frames an hypothesis to account for the action of animal 
charcoal in decolorizing vegetable solutions and in ab¬ 
sorbing lime from a solution of sugar-lime. lie con¬ 
nects the undoubted fact that such charcoal absorbs and 
condenses large quantities of the atmospheric gases with 
the powers named, by assuming that the decolorizing 
power is due to the oxidizing power of condensed oxygen, 
and the lime absorbing' action to the carbonic acid con¬ 
tained in the pores. He does not quote any experiments 
in support of his view. _ ^ 
f he abstractor states that animal charcoal deprived, 
of its gases by heating to redness in a JSprengel vacuum, 
is. capable of decolorizing a solution deprived of dissolved 
air (and retained in vacuo) as perfectly as the ordinary 
material .—Journal of the Chemical Society. 
1 oi some qualifications ot this statement, vide Itoscoe’s. 
Spectrum Analysis.’ 
f Deut, Chem. Ges. Bei\, v. 282. 
t Dingl. Polyt. J., cciii. 63-66. 
