DR. T. S. HUMPIDGE ON THE ATOMIC WEIGHT OF GLUCINUM. 
G05 
I first attempted Debray’s method, but owing to the difficulty of procuring 
compact boats of lime or of a mixture of lime and alumina of sufficient size, no good 
results were obtained. Nor did I get good results with Nilson’s process. I found 
considerable difficulty in excluding the oxygen of the air; the tubes could scarcely be 
unscrewed again when cold, as the sodium chloride had solidified in the thread, and 
when opened it was not easy to extract the metal without contamination from the 
outside scale. A modification of the two methods was therefore adopted, which 
answers admirably. 
Iron boats were constructed of pieces of tubing partly filed away, and with end 
pieces screwed on. They were about 200 millims. long and 20 millims. in diameter. 
In order to prevent any contact of the reduced metal with the glass of the tubes, the 
boats were enclosed in slightly longer pieces of entire iron tubing, and in these cases 
were introduced into a wide tube of hard glass. As in Debray’s method, the first 
boat contained about the requisite quantity of sodium, the second the glucinum 
chloride. When the tube had been filled with dry hydrogen, the boat containing the 
sodium was heated until the metal was fused, the heating was then continued 
backwards to the chloride, the vapour of which thus passed, mixed with the excess of 
hydrogen, over the molten sodium. After the somewhat violent reaction had ceased 
and the tube was again cold, the boat containing the reduced glucinum, together with 
the sodium chloride produced and the excess of sodium, was placed in a vessel of 
crude alcohol until hydrogen ceased to come off. It was then removed to water to 
dissolve out the sodium chloride. Compact crystalline masses of glucinum were thus 
obtained, always, however, mixed with more or less basic chloride and oxide, even 
when the experiment was most carefully conducted. The larger pieces of metal could 
be easily removed from the liquid and purified by washing with cold dilute caustic 
soda, which dissolves out any oxide, but is without action on the metal. The residue 
was then likewise treated with caustic soda, and preserved separately as being less pure. 
The iron boats and tubes were not attacked during the reaction, except that blisters 
were raised on the outer tubes which, unlike the boats themselves, were of steel. 
The metal was of a steel-grey colour not so white as aluminium, but considerably 
harder, and can be beaten into thin sheets under the hammer. Compressed in a steel 
mortar it yielded a compact disc of metal—0'7 gramme thus treated gave a disc 
15 millims. in diameter and 3 millims. thick. Its specific gravity at 10° C. was found 
to be 1‘84, or making allowance for the impurities present, 170. As it was suspected 
that the metal so compressed might still contain air, it was first boiled for half an hour 
m water before determining its specific gravity. All attempts to fuse the metal were 
without any good result. It remained apparently unaltered when heated to bright 
redness in the air, and probably became covered with a thin coating of the oxide. 
Heated under sodium chloride in a lime crucible by the oxyhydrogen flame imperfect 
fusion was obtained. When similarly heated and exposed to the air it burnt with a 
dazzling, bluish light. The metal dissolved readily in dilute acids leaving a minute 
mdccclxxxiii. 4 I 
