92 
POPULAR SCIENCE REVIEW. 
spectrum of the nitrate exhibits three bands at least in the indigo and blue. 
The most refrangible band is a little smaller than that of philippium, or the 
m of didymium. It occupies a space between Fraunhofer’s lines G and H ? 
being rather nearer to G, at a point where didymium and terbium show no 
lines ; then there are two bands in the violet which appear to be H and H'. 
References to the wave-lengths of these and other bands will be found in the 
author’s paper. The North Carolina samarskite has now been shown to con- 
tain the following earths : — 
Name. 
Yttria . 
Erbia . 
Terbia . 
Philippia 
Decipia 
Thorina 
Equivalent. 
YO = 74-5 
ErO = 130 
TbO = 114-115 
PpO = 90 (about) 
DpO = 122 (about) 
Th0 2 = 267-5 
as well as the oxides of didymium and 
following interesting relation between the 
group : — 
Yttrium .... 
Philippium .... 
Terbium .... 
Decipium .... 
Erbium . . 
cerium. Delafontaine traces the 
equivalents of some metals of this 
58 
74 = 58 + 2x8 
98 = 58 + 5*8 
106 (?) = 58 + 6 x 8 
114 = 58 + 7x8 
Mosandrum . — According to J. L. Smith, a new metallic element, to which 
he has given the above name, occurs in some of the native columbates. He 
refers to it in a paper published July last in the “ Comptes Rendus ” (1878, 
lxxxvi., 148) on the analysis of these minerals. He directs attention to the 
action of concentrated hydrofluoric acid on the samarskite and euxenite of West 
Carolina, which is as rapid and energetic as that of hydrochloric acid on calc- 
spar. By the application of the heat of the water-bath the powdered mineral 
can be completely broken up in a few minutes. He finds that the earths of the 
yttria group present in these minerals consist of one-third erbia and two- 
thirds yttria. The group contains no cerium, but nearly 10 per cent, of 
thorina, a small quantity of didymium oxide, and 3 per cent, of an earth 
which he believes to be new to science. lie makes the atomic weight of the 
new earth to be 109 (when O = 16), those of oxide of cerium and lantha- 
num being 110, and of oxide of didymium 112, according to Marignac. The 
new oxide is stated to differ from the earths of the yttrium group as regards 
its reaction with potassium sulphate ; from cerium oxide by its being soluble 
in very dilute nitric acid, or in an alkaline solution through which chlorine 
has been conveyed ; from didymium oxide by its colour as well as in other 
features, especially the absence of the characteristic absorption bands ; and 
from lanthanum oxide by its colour, the crystalline form of the salts, &c. 
It appears that the discovery was communicated to the Academy of Sciences 
more than a year ago, and publicly announced at Philadelphia in May last 
year. Marignac, who can speak with authority on the question, does not 
find in any of the reactions quoted by the discoverer sufficient reasons for 
distinguishing the earth in question from terbia. He finds that the sulphate 
