Oct. 14, 1886 | 
NATURE 
585 
soiled by traces of other earths’’), andalso many specimens pre- 
pared by myself at different times and purifiel up to the highest 
degree known at the time of preparation. Practically these 
earths are all the same thing, and up to a year ago every living 
chemist would have described them as identical, z.e. as the 
oxide of the element yttrium. They are almost indistinguishable 
one from the other both physically and chemically, and they give 
the phosphorescent spectra 272 vacuo with extraordinary brilliancy. 
This is what I formerly called yttria, and have more recently 
called o/d yttria Now these constituents of old yttrium are not 
impurities in yttrium any more than praseodymium and neo- 
dymium (assuming them really to be elementary) would be im- 
purities indidymium. They constitute a veritable splitting up 
of the yttrium molecule into its constituents. 
The plan adopted in the fractionation of yttria does not differ 
in principle from the methods described in my former paper 
** On the Methods of Chemical Fractionation.” Dilute ammonia 
is added to a very dilute solution of the earth in only sufficient 
quantity to precipitate one half. After standing for several 
hours the precipitate is filtered. After each fractioning the 
filtrate is passed to the left and the precipitate to the right, 
and the operations are continued many thousand times. 
The diagram (Fig. 2) shows the scheme clearly, with the 
¥ 
RON ORO 
ae 
ere 
Tie 
“SPECTRA. OF, . FIYE;COMPONENTS OF  /YTTRIA 
| direction the precipitates and solutions travel. Limited space, 
eyen on a large diagram, prevents me from giving more than a 
few operations, but they will be sufficient to satisfy you that 
enormous patience, a large amount of material, and a not in- 
significant number of bottles, are requisites for successful frac- 
| tionation. Such proceedings are tedious enough even in their 
| narration, but no mere words can enable any one to realise the 
| wearisome character of these operations when repeated day by 
day, month after month, on long rows of Winchester quart 
bottles. 
After a certain time, on examining the series of earths in the 
lowest line of bottles, their phosphorescent spectra are found to 
alter in tle relative intensities of some of the lines, and ulti- 
mately different portions of the fractionated earths show spectra 
such as I have endeavoured to illustrate at the foot of the 
diagram (Fig. 2), where I give the spectra of five components of 
yttrium. 
The final result to which I have come is that there are certainly 
five, and probably eight, constituents into which yttrium may be 
split. Taking the constituents in order of approximate basicity 
(the chemical analogue of refrangibility), the lowest earthy con- 
stituent gives a deep blue band, Ga (A 482); then there is a 
strong citron band, G5(A 574), which has increased in sharpness 
TRIA. 
er 
EX 
cece 
BAGS 
: SEAS 
Sst ss 
a 
\ 
<!) 
N 
oe 
\ 
CHoMe 
lil 
FIG 2) 
till it deserves to be called a line; then come a close pair of 
greenish-blue lines, GB (A 549 and A 541, mean 545); then a 
red band, G¢ (A 619), then a deep red band, Gy (A 647), next a 
yellow band, Ge (A 597), then another green band, Gy (A 564) ; 
this (in samarskite and cerite yttria) is followed by the orange 
line S35 (A 609). The samarium bands remain at the highest 
part of the series. These, I am satisfied, are also separable, 
although for the present I have scarcely touched them, having 
my hands fully occupied with the more easily resolvable earths. 
The yellow band, Ge, and green band, Gy, may in fact be due 
to a splitting up of samarium. 
Until we know more about these bodies I refrain from naming | 
them, but will designate them provisionally by the mean wave- 
length of the dominant band. If, however, for the sake of 
easier discussion among chemists a definite name is thought to 
be more convenient, I will follow the plan frequently adopted in 
such cases, and provisionally name these bodies as shown in the 
table given below. 
The initial letters S and G recall the origin of the earths 
respectively from Samarskite and Gadolinite. 
Not only has yttrium been split up by subjection to fractiona- 
tion, but samarium, as I have hinted above, is likely to prove | 
equally unable to resist this operation. In the phosphorescent 
spectrum of samarium sulphate the line Sd (609) is one of the 
constituents. When yttria is added to samaria this line is deve- 
| loped in greater intensity, as yttria has the power of deadening 
| the other bands of samarium, while it does not seem to affect the 
| 
| ar . ¢ > I A 
| ee Boek Probability 
| 3 Ss 
Bright lines in— 
Deep blue 8:93t 482 4304 Ga New , 
Greenish-blue New, or the Z3 of 
(mean of ar 9°650 545 3367 GBS M. de Boisbau- 
close pair... \ dran 
Greensn...:- 1s 9812 564 3144 Gy New 
| ( New, or the Za of 
Ie Citron .s..:0:.- 9890 574 3035 Gd M. de Boisbau- 
dran 
Yellow......... 10°050 597 2806 Ge New 
Orange... I0o'l29 609 2693 S6d New 
ime Red).2..<....... 10285 610) 260r GG New: 
Deep red...... 10°338 647 2389 Gn New 
| line Sd. Several circumstances, however, tend to show that 
although line S55 accompanies samarium with the utmost per- 
