1899.] , SCIENCE. 105
regards atomic weight, is hydrogen 1, proto-calcium 10, proto-magnesium 12, and oxygen 16 ; and that stellar evolution and Mandeleef may thus be brought into agreement. He does not, however, say what would happen were oxygen itself, as he supposes, "a highly complex thing."
Monium has been renamed victorium, in consequence of the Queen's long reign. It is an earth of a pale brown colour, less basic than yttria, easily soluble in water, and able to form a double sulphate of victorium and potassium. Its atomic weight is about 117.
Hydrogen has no metallic appearance as a solid since it resembles ice. As a fluid its density is •066. Its melting point is 16° C. above absolute zero, and its boiling point is 27°. The lowest absolute tem- perature attained by Professor Dewar in obtaining these values was 14° under a pressure of 36 mm.
The iodine present in surface sea-water is not due to a solution of iodides or iodates, but it exists as part of the structure of minute organisms. In the depths, however, the salts are found and the organ- isms have vanished, the reversal taking place gradually. This must result from the assimilation of iodine by the infusoria that inhabit the upper oceanic layers, and from its discharge as these creatures perish and subside.
If halogen salts do not attack aluminium it is because a protective film of aluminium hydroxide has covered it. This coating is removed by a small quantity of a dilute acid, and then the destructive action of the saline solution proceeds. Carbonic anhydride is sufficient for this purpose even in river waters, and in the sea corrosion quickly extends into the metal with the formation of a double sodium aluminium carbonate.
The thin layer of grease that covers aluminium cooking utensils is generally dislodged by the aid of alkaline solutions, and these have such an erosive action on the metal that the vessels are soon rendered useless. Another objection to the culinary employment of aluminium is its high specific heat, 214, as compared with 114, which is that of iron.
Physics.
Light is penetrating the dark places of magnetism.
M. Cornu, desiring to explain the difference between the Zeeman and the Faraday phenomenon, supposes that in the former, when the magnetic force acts on the luminous body, the light is changed in its period whilst its velocity of propagation is unaffected ; whereas in the latter case the velocities of the two components are altered whilst their period is undisturbed.
MM. Macaluso and Corbino have experimented on the Faraday effect in gases. It appears that the rotatory efficacy of a substance greatly increases as the frequency of the transmitted light approaches that of the absorption band of the substance through which it is transmitted.
Professor Righi's discoveries have been confirmed. A vapour, such as the sodium-flame, capable of absorbing light is placed between the pole-pieces of an electro-magnet. These are so pierced that a polarised
