HARDWICKE'S SCIENCE-GOSSIP. 



87 



Mr. M. W. Harrington, an Ameri»an astronomer, 

 is of opinion that the physical condition of the little 

 planet Vesta is similar to that of our moon, being 

 devoid of water, and also of a perceptible atmosphere. 



White bronze is being manufactured in Germany 

 from the powder of the mother-of-pearl inside 

 meleagrina. 



The vapour of bisulphide of carbon is being 

 employed in New York instead of steam. It boils at 

 118°, and its volume at the same temperature at 

 which water is converted into steam is approximately 

 as three to two compared with water vapour. More- 

 over, its volume increases in the heat. 



At a meeting of the Royal Society of South 

 Wales, Professor Liversidge produced some flints, 

 and said white powdery limestone had been brought 

 from New Britain so exactly resembling chalk that 

 he thought true chalk of Cretaceous age occurred in 

 the South Sea Islands. If this is the case, it upsets 

 a good deal that has been said about the "perma- 

 nency " of the great ocean basins. 



Crops of the freshwater sponge {Spoiigilla Jliivia' 

 tilis) have formed in such immense quantities in one 

 of the Boston (U.S.) waterworks storage tanks, that 

 the odour and taste of the water became so offensive 

 the water could hardly be drunk. 



Professor Hull and his party have returned 

 from their survey of the Jordan Valley. One of the 

 river-terraces of the Jordan was found at a height of 

 "600 feet above the present level of the Dead Sea. 

 Professor Hull will doubtless put the results fully 

 before the scientific world before long. 



At a meeting of the Entomological Society the 

 other day, several members expressed their opinion 

 that the butterflies of this country are becoming scarcer. 

 This is especially the case in the neighbourhood of 

 large towns. Can it be from the smoke and dis- 

 engaged gases thrown into the atmosphere ? If the 

 insects go, our most beautiful flowers will soon follow. 



A French geologist, M. Chaper, is said to have 

 found the matrix of the Indian diamonds at Naizam, 

 near Bellay, in the Madras Presidency. The matrix 

 is composed of pegmatite — a binary granite, com- 

 posed of felspar and quartz. The diamonds were 

 found chiefly where the rock was traversed by veins 

 of felspar, and quartz containing epidote. The 

 diamonds are weathered out of their matrix into the 

 soil. 



Mr. Charles Collins (nephew of Mr. C. Collins, 

 the well-known microscope manufacturer) is issuing 

 a special set of excellently mounted slides illustrating 

 the skins and scales of fishes. As the reader will see 

 by referring to the earlier volumes of Science-Gossip 

 (where the scales of many British fishes are illustrated) 

 they are very beautiful objects. 



Professor Hughes's lecture on 'The Theory of 

 Magnetism,' at the Royal Institution, has created a 

 great effect. The mechanical theory of magnetism 

 may be deemed to be the proper style and title of 

 that brought forward by the lecturer. The pheno- 

 mena of magnetism he explained by a simple rotation 

 of the molecules of iron, as well as of all metals, nay 

 more, of all matter, solid, liquid, gaseous, or ether. 

 All matter, according to his views, has inherent 

 magnetic power, varying in degree in molecules of 

 different nature, but not to any great extent. The 

 lecturer demonstrated each portion of his theory by 

 experiment, so that the effects were visible to the 

 audience. He expressed his belief that electrical 

 currents can be fairly classed with heat as a mode of 

 motion. When a bar of soft iron is strongly mag- 

 netised, as in the instance of an electro-magnet, it 

 returns, like a spring, to a neutral state upon the 

 cessation of the inducing force. This well-kno^yn 

 fact has long remained a mystery. All theories of 

 magnetism have hitherto supposed that the molecules 

 became, on the removal of the induced current, mixed 

 or heterogeneous. Professor Hughes believes he has 

 made a great discovery in having solved this problem, 

 leaving no mystery any longer, as the demonstration 

 he subsequently brought forward before the Royal 

 Society reduced the matter within the domain of 

 absolute fact. He proved his case before his audience 

 at the Royal Institution in a less formal way, but 

 quite as effectually, rendering a bar of iron sensibly 

 neutral or polarised at will by simply turning it upside 

 down. The mechanical inertia of the molecules was 

 demonstrated by magnetising a bar, and then chang- 

 ing its polarity by the earth's influence alone. The 

 inertia of magnetism and of electricity was illustrated 

 by two bars of diverse hardness. Having dealt with 

 other points of great interest, the lecturer concluded 

 by saying that scientific men are agreed that heat is a 

 mode of motion, and that the molecules of the most 

 solid bar of iron can move in a certain space with 

 comparative freedom, the oscillations being greatly 

 increased with every rise in temperature. If, as 

 already well known, the molecules can move in all 

 planes, then there could be no valid objection to the 

 idea of their rotation, in fact they wei-e known to 

 rotate in the act of crystallisation. Thus, according 

 to Professor Hughes, magnetism is an endowment of 

 every atom of matter. 



The officials for the meeting of the British Associ- 

 ation at Montreal, on the 27th of August, have been 

 appointed, and are as follows : President, Lord 

 Rayleigh ; Sectional President, Mathematical and 

 Physical Science, Prof Sir William Thomson ; 

 Chemistry, Prof Roscoe ; Geology, W. T. Blandford ; 

 Biology, Prof Moseley ; Geography, Col. Rhodes ; 

 Economical Science, Sir R. Temple ; Mechanical 

 Science, Sir F. J. Bramwell ; Anthropology, Dr. E. B. 

 Tylor. 



