May 1, 1885.] 



SCIENCE. 



371 



ing territories, so far as they are not occupied by 

 European powers, are free from any form of state 

 rule or possession. 



— Bouquet de la Grye is ordered by the French 

 ministry of instruction to proceed to Teneriffe, in 

 order to study the laws of gravitation under all the 

 circumstances for which the Peak offers facilities. 



— Dr. Pechuel Losche reports curious changes in 

 the physical geography of Africa: "Lake Ngami 

 is dried up; the game has died or gone away; the 

 vegetation exists no longer; both the Okavango and 

 the Tamakan flow into the Zambezi." Dr. Pechuel 

 Losche returns to Europe with rich collections, in- 

 cluding a living Welwitschia, perhaps a new species 

 of that curious plant. 



— Dr. Lenz will leave Vienna in May for the upper 

 Kongo, whence he will endeavor to cross the old 

 equatorial province of Egypt in order to establish 

 relations with Emir Bey and Lupton Bey's party. 



— Dr. Silvers of Hamburg, who left that town in 

 October, 1884, on an exploring expedition to the Cor- 

 dillera of Merida in Venezuela, arrived at Tovar on 

 Jan. 9, and from there will commence his explora- 

 tions. 



— The Semaphore de Marseille reports a method of 

 sugar-manufacture which is to supersede beet-root 

 by potatoes, the saccharine matter being extracted by 

 the help of electricity. Paris capitalists, and even 

 English, are reported to be interested in the inven- 

 tion. 



— The Marine biological association of England 

 has already raised six thousand pounds of the fund 

 required to found a station on the south coast of 

 England, but requires four thousand pounds more 

 before beginning to build. Cambridge has under- 

 taken to raise five hundred pounds. 



— A correspondent of the OesterreicJiische monats- 

 schrift fur den orient writes, that if the reports of the 

 few parties who have succeeded in gaining personal 

 knowledge of the interior of the celestial empire 

 did not agree in the fact that a kingdom of four hun- 

 dred million inhabitants awaits the products of Eu- 

 ropean factories, which will be opened to commerce 

 by the introduction of modern means of intercourse, 

 the beginning of the development of European in- 

 dustries in the interior, as evidenced in the last few 

 years, would awaken immediate and serious anxiety 

 for the future of the English trade. Led by their 

 position, Hong-Kong and Shanghai are setting a good 

 example in this direction to the other places which 

 come in contact with European civilization. Hong- 

 Kong has at present three large sugar-refineries, a 

 spirit-distillery, a cordage-mill supplied with modern 

 machines, and an ice-factory. Besides these, there 

 are large glass and iron works, and an arrack-distil- 

 lery, in course of construction; while the Chinese 

 carry on woollen and cinnabar works in great style 

 and with modern improvements. In Shanghai, to the 

 establishments which have existed for several years, 

 there was added, a few months ago, a new one of 

 considerable importance, — the paper-factory of the 



Shanghai paper-mill company, which makes common 

 and medium fine papers out of rags. This factory, 

 established by Umpherston & Co. of Leith, and quite 

 up to time in its plant, produces, on an average, two 

 tons of paper a day; and later the production will be 

 increased. It is under European direction, and em- 

 ploys only Chinese workmen. 



— With a view to effectually prosecute marine fish- 

 culture on sound scientific principles, the English 

 national fish-culture association has under considera- 

 tion a scheme for carrying out a series of observations 

 on the temperature of the sea at various stages, in 

 order to obtain a more thorough and concise knowl- 

 edge of fish, their habits, food, etc. Thermometers 

 for this purpose will be distributed to those selected 

 for observers under certain rules and regulations. 



— From experiments carried on by the French com- 

 mission for the scientific study of firedamp, it is 

 found that the most violent explosion takes place 

 when there are 13 parts of air to 100 of firedamp, and 

 that above or below this the explosion diminishes in 

 violence. When the mixture is below 7 parts in 100, 

 or above 18 in 100, the gas simply burns with its char- 

 acteristic blue flame. The singing noise often heard 

 in mines is ascribed to the escape of gas from many 

 minute cavities; while it must exist in some places 

 in vast quantities, as is witnessed by its use for illu- 

 minating-purposes. 



— Prof. J. A. Ewingof University college, Dundee, 

 has communicated a paper to the Royal society, which 

 contains several points of immediate practical im- 

 portance. He finds, for example, that the ' dissipa- 

 tion of energy ' by reversal of magnetism is very 

 much smaller in soft iron than in hard iron or steel, 

 and even in the latter its amount is trifling; so that 

 the principal part of the heat which is produced in 

 the cores of electro-magnets must be due chiefly to 

 other causes than the ' static hysteresis/ or static 

 lagging action observed by Professor Ewing, and is, in 

 fact, due almost wholly to the induction of so-called 

 Foucault currents in the cores. The effects of this 

 action are also almost entirely removable by vibrat- 

 ing a piece of soft iron during the application and 

 removal of magnetizing force, and the iron is then 

 found to possess almost no retentiveness; but, when 

 the application and removal of magnetizing force are 

 effected without mechanical disturbance, the reten- 

 tiveness of soft iron is found to be even greater than 

 that of steel. In some cases ninety-three per cent of 

 the whole induced magnetism of a piece of annealed 

 iron was found to remain on the complete removal of 

 the magnetizing force. Examples were given to show 

 that the influence of permanent set in the curve of 

 magnetism is so marked as to give a criterion by 

 which a strained piece may be readily distinguished 

 from an annealed piece of metal; and that strain di- 

 minishes very greatly the magnetic retentiveness of 

 iron. 



— Capt. Hoffmann of the German navy has pre- 

 pared a valuable pamphlet on ocean-currents (Zur 

 mechanik der meeresstromungen an der oberflache 

 der oceane, Berlin, 1884), which gives a better 



