60G DR. T. S. HUMPIDGE OK THE ATOMIC WEIGHT OF GLUCINUM. 
trace of insoluble matter, quite imponderable. When 3 centigrammes were dissolved, 
the residue could not have been as much as O'l milligramme. To determine the 
amount of iron contained in it, 0'0341 gramme was dissolved in dilute sulphuric acid 
in a stream of carbonic acid, and then required 1*4 cc. of a potassium permanganate 
solution of which 1 cc. was equivalent to 0"32 milligramme iron, which gives the 
percentage of iron present to be 1 '32. The oxide mixed with the metal was found by 
dissolving 0‘0340 gramme of the metal in dilute hydrochloric and precipitating the 
hydrate with ammonia and weighing, after thorough washing, as oxide. The amount 
taken gave 0'0883 gramme oxide, corresponding to a percentage of 4*71. The 
composition of my metal was therefore :— 
G1.. . = 93-97 
G1o0 3 .= 4-71 
Fe.= 1-32 
Si0 3 .= traces 
100-00 
That obtained by M. Nilson, the only other sample which has been analysed, had 
the composition : — 
G1.= 87-09 
Gl 3 Og.= 9-84 
Fe.= 2-08 
Si0 2 .0-99 
100-00 
I believe it is possible by using purer chloride to obtain a metal almost chemically 
pure by the method described above. 
The position of glucinum in the electro-chemical series is a peculiar one, and deserves 
passing notice. In dilute acids (hydrochloric, nitric or sulphuric) glucinum is strongly 
electro-negative to magnesium, and feebly positive to aluminium. In caustic potash 
or caustic soda, the series is different, and glucinum is now negative to both metals, 
feebly to magnesium, strongly to aluminium ; while in ammonium carbonate the 
series is the same as for dilute acids. These results may be thus tabulated;— 
(i.) Dilute acids and ammonium carbonate. 
+ Mg, Gl, Al- 
(ii.) Caustic alkalies. 
+A1, Mg, Gl- 
