604 D R. T. S. HUMPIDGE OH THE ATOMIC WEIGHT OF GLUCINUM. 
In the fused state it readily conducts an electric current with the formation of 
metallic glucinum at the negative pole. The metal so obtained is, however, largely 
contaminated with impurities derived from the vessel in which the experiment is 
conducted, which is strongly attacked by tire free fluorine. In one experiment with 
platinum electrodes—the positive electrode being a platinum crucible in which the 
salt was fused—the crucible lost two decigrammes in weight. The double fluoride 
may also be decomposed by fusion with sodium or potassium, but in this case also 
only a very impure product results, owing to corrosion of the vessels employed. It is 
possible that by using an iron crucible a purer metal might be obtained. 
The metal used in the determination of its specific heat was prepared from its 
chloride, which compound was obtained in the usual way by heating a mixture of the 
oxide and sugar charcoal in dry chlorine. I have found it better to employ starch 
paste (made of pure wheaten-starch) in place of the oil which is commonly recom¬ 
mended for mixing the oxide and charcoal. If starch paste is used a much more 
compact mass is obtained after the subsequent glowing in charcoal powder, but which 
is still sufficiently porous to allow the chlorine to penetrate into the interior. It is 
advisable to employ a hard glazed porcelain tube for heating the mixture in the stream 
of chlorine, this being far less attacked by the, chloride than hard glass. Absolute 
purity of the oxide used to prepare the chloride is not necessary, as, owing to the high 
temperature at which glucinum chloride condenses, any traces of aluminium or silicon 
which may be present are carried, with traces of the chloride, to the less heated 
portions. If, however, iron is present, it is not completely removed. 
Glucinum chloride melts at about 600 ° (Carnelly) to a brown liquid, of which the 
electric resistance is so great that it is apparently not decomposed even by a powerful 
current. On connecting the wires from a battery of forty quart Bunsen cells in series 
with platinum electrodes dipping in fused glucinum chloride and with a galvanometer, no 
deflection of the needle of the instrument was observed. I can therefore confirm 
Wilson’s result that the chloride is practically a non-conductor of electricity. The 
fused or gaseous chloride is readily decomposed by sodium, but if vessels of platinum, 
porcelain, or glass are used the metal obtained is largely contaminated with impurities 
derived from the vessels. To overcome this difficulty Debray* used lime. He con¬ 
structed boats of a mixture of lime and alumina, placed sodium in the first and the 
chloride in the second, then introduced them into a tube of hard glass through which 
was passed a stream of dry hydrogen. The boat containing the sodium was first heated, 
then that containing the chloride, so that its vapour was carried by the stream of 
hydrogen over the fused sodium. The metallic glucinum so obtained was a compact, 
fibrous, crystalline mass, and was probably purer than any prepared in platinum vessels. 
Nilson and Petterson first proposed iron vessels for the reduction of the chloride. 
They heated equivalent quantities of the chloride and sodium in a massive iron 
cylinder and thus obtained a metal resembling Debray’s, and comparatively pure. 
* Loc. cit. 
