July 27, 1872.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
(55 
Query: Is this acid or the substance from which it is 
produced the active principle of cotton root ? 
The cotton-seed cake (the mass left after pressing out 
the oil) contains more or less of it, and I am informed by 
Dr. John A. Warder that cows fed upon it will abort, 
otherwise it is a nutritious food for cattle. Some of the 
substance I have placed in the hands of practitioners for 
practical test, but as yet have had no report concerning 
it .—American Journal of Pharmacy. 
THE LAST NEW METAL, INDIUM.* 
BY WILLIAM ODLIXG, ESQ., M.B., E.B.S. 
{Continued from page 48.) 
Now the salts of the alkali-metals, lithium, sodium 
and potassium, and certain of the salts of the alkaline- 
earth metals, calcium, strontium and barium, being very 
readily volatile, upon heating these salts, in the non- 
luminous flame of a Bunsen gas-burner for example, 
they undergo vaporization, and their vapours become 
incandescent and capable of yielding the characteristic 
emission spectra of the particular metals. In examining 
in this way the alkali-salt residue of a mineral water 
from Durkheim, Bunsen observed in the spectrum before 
him certain coloured lines not belonging to any one of 
the then known alkalies, potash, soda or lithia ; and yet 
necessarily belonging to some substance having the 
general characters of an alkali, since all other bodies 
than alkalies had been previously removed from the 
residue under examination. In full reliance upon the cer¬ 
tainty of this conclusion, Bunsen evaporated some forty 
tons of the water in question ; and from the alkali-salt 
residue succeeded in extracting and separating salts of two 
new alkali-metals, eachcharacterizedby a well-marked pair 
of lines in the blue or indigo, and one of them having 
in addition a pair of well-marked lines of extremely 
small refrangibility in the red of the spectrum. From 
its yielding those red lines one metal was named rubi¬ 
dium ; the other, of which the bright blue lines were 
especially characteristic, being called emsium. 
The very general distribution in nature of these two 
elements was speedily established, and salts of each of 
them were with much labour eventually prepared in a 
state of purity and in reasonable quantity. From cer¬ 
tain of their respective salts the metals themselves were 
obtained by the usual processes, and together with their 
salts, were submitted to detailed chemical examination. 
And no sooner was this examination made,, than the 
position of the newly discovered elements, as members 
of the. alkali-metal family, at once became apparent. 
Rubidium and caesium were found in all their properties 
to present the most striking analogy to potassium, and 
evidently to stand to this metal in the same relation that 
strontium and barium respectively stand to calcium; 
while they differ from sodium, much as strontium and 
barium respectively differ from magnesium. This rela¬ 
tionship in obvious properties was further borne out by 
the relationship of their atomic weights, thus 
Mg 24 ... . 
Na 23 
F 19 ... . 
O 
16 
fCa 40 ... . 
(K 39 
( Cl 35-5. . . . 
1 S 
32 
Sr. 87 ... . 
< Rb 8-5 
| Br 80 .... 
{ Se 79 
[ Ba 137 .... 
( Cs 133 
( I 127 .... 
( Te 129 
It is observable that the sequence of atomic weight in 
the thus completed alkali-metal family, is strictly parallel 
to the previously well-known sequences in the alkali-earth 
metal family, and in the halogen and oxygen families 
respectively. Moreover, just as the basylity of the alka¬ 
line-earth metals increases in the order of their several I 
atomic weights—calcium being less basylous than stron¬ 
tium, and far less basylous than barium—so also is 
the basylity of potassium inferior to that of rubidium, 
and the basylity of rubidium inferior to that of caesium, 
* Lecture delivered at the Royal Institution, Jan. 19, 1872. 
' which is indeed the most powerfully basylous, or oxi- 
| dizable, or electro-positive element known. 
Since 1860, both rubidium and caesium have been 
recognized as minute constituents of a considerable num- 
j ber of minerals and mineral waters, rubidium having 
been met with for the most part in a larger proportion 
by weight than caesium. Unlike potash, originally 
known as vegetable alkali, caesium has not been recog¬ 
nized in the vegetable kingdom; but rubidium has been 
found as a very common minute constituent of vege¬ 
table ashes, as those of beetroot, oak-wood, tobacco, 
grapes, coffee, tea, etc. On the other hand, caesium, 
free from rubidium, has been found in a tolerably well- 
known, though rare, mineral from the Island of 
Elba, to the extent of 32 per cent, by weight of the 
mineral. The history of this minei’al is curious : from 
the circumstance of its always occurring in association 
with another mineral, a variety of petalite, the two were 
called Castor and Pollux. Castor was found to be sub¬ 
stantially a silicate of alumina and lithia; pollux a sili¬ 
cate of aluminia, and, as it was thought, of potash. The 
constituents of pollux, namely, silica, alumina, and 
potash, with small proportions of ferric oxide, lime, soda 
and water were duly estimated ; but the quantities of 
these constituents found in 100 parts of the mineral, 
instead of amounting to 100 parts or thereabouts, 
amounted only to 88 parts, there being somehow a loss 
of 12 per cent, in the analysis. After Bunsen’s dis¬ 
covery of the now alkali-metals, pollux was analysed 
afresh by Pisani, who soon perceived that what had 
formerly been taken for potash, and estimated as 
potash, was not potash at all, but emsia. Then calcu¬ 
lating out his own analysis with ccesia instead of potash, 
substituting the one for the other in the proportion of 
of 133 + 8, or 141 parts of cassia, for 39 +■ 8, or 47 
parts of potash, he found that the quantities of the 
different constituents furnished by 100 parts of the 
mineral yielded by their addition the full sum of 100 
parts required. 
In submitting to spectroscopic examination a certain 
residue left by the distillation of some impure selenium, 
Mr. Crookes, early in 1861, recognized in the spectimm be¬ 
fore him a brilliant green line, from which he inferred the 
presence in the above residue of a new element; and by 
the end of the same year, he had succeeded in esta¬ 
blishing the tolerably wide distribution of this element, 
to which he gave the name of thallium ; in procuring 
it, though but in small quantity, in a separate state ; 
and in satisfying himself of its metallic character. 
Soon afterwards, and without knowledge of Mr. Crooke’s 
later results, the metal was obtained by M. Lamy on a 
comparatively large scale, and was exhibited by him in 
the form of small ingots at the London exhibition of 
1862. He procured it from the fine dust met with in 
some oil of vitriol factories, as a deposit in the flues 
leading from the pyrites burners to the leaden cham¬ 
bers. In these deposits, the minute proportion of thal¬ 
lium contained originally in the pyrites becomes con¬ 
centrated, so as to form in some instances as much as 
8 per cent, by weight of the dust. Independently, 
moreover, of its occurrence in iron pyrites, thallium, 
though never forming more than a minute constituent 
of the different minerals and mineral waters m which it 
occurs, is now known to be capable of extraction from a 
great number and variety of sources. But from no other 
source is it so advantageously procurable as from the 
above-mentioned flue deposit; and so early as the 
autumn of 1863, at the meeting of the British Associa¬ 
tion in Newcastle, the then mayor, Mr. J.’ Lowthian 
Bell, exhibited several pounds, and Mr. Crookes no 
less than a quarter of a hundredweight of thallium 
obtained from this comparatively prolific source. In 
one respect, the discovery of thallium presented even a 
greater degree of interest than attached to the discovery 
of cfesium and rubidium. For whereas theso two ele¬ 
ments were at once recognized as analogues of the well- 
