Page:Proceedings of the Royal Society of London Vol 60.djvu/476

444 Malacone, ZrS04, from Hitteroe in Norway, was the only mineral in which argon was found. Five grams of the mineral gave 12 c.c. of gas unabsorbed by caustic soda. After explosion with oxygen, and absorption of the residual oxygen with phosphorus, about OT c.c. of gas remained. The residue was introduced into a tube with aluminium electrodes which was sealed off from the pump and attached to a coil giving a discharge sufficiently powerful to heat the electrodes to a red heat. The nitrogen was quickly absorbed by the red-hot electrodes, and, as soon as the banded spectrum had disappeared, the lines of helium and argon became visible. The green line of the helium spectrum was very strong, and the glow in the tube was distinctly green.

The argon present was in too large quantity to be attributed to accidental leakage of air into the apparatus ; but, in order to confirm this exceptional result, and also to determine whether the green effect in the tube was due entirely to the low pressure of the helium, the experiment was repeated with a larger quantity of the mineral. With 10 grams of the mineral a quantity of gas was obtained, which, after removal of nitrogen, gave a yellow glow in the vacuumtube ; argon was again present, and its second spectrum could be brought out very strongly by means of a jar and a spark-gap in the secondary circuit. The experiment was repeated a third time with the same result. This proved conclusively that malacone contains both argon and helium.

Cinnabar.—Five grams gave 0‘5 c.c. of gas, which consisted only of carbon monoxide.

Cryolite.—7'6 grams gave only a minute bubble of carbon monoxide. Apatite.—Six grams gave 05 c.c. of a gas consisting wholly of hydrogen and carbon monoxide.

Baryta-celestine.—No gas was evolved; the pump remained at a phosphorescent vacuum.

Serpentine.—This specimen was from the Riffelhorn, and has been analysed by Miss Aston; 5 grams gave 4 c.c. of gas which consisted wholly of hydrogen.

Gneiss, from the Diamirai Glacier, directly below the peak of Nanga-Parbat, Kashmir, brought home by Dr. Collie: 3 grams gave 6 c.c. of hydrogen.

Scapolite, a silicate of calcium, magnesium, and aluminium, gave no gas.

Cobalt ore, containing a considerable quantity of manganese dioxide:—3'2 grams of mineral, heated alone, gave 35 c.c. of gas consisting wholly of oxygen.