July 24, 1891.] 



SCIENCE. 



47 



became of the same volume as the m.olten metal which it joined. 

 Any one could see by the distance that the piece of iron went 

 above the surface that it was of considerably less density than the 

 molten metal. 



— The German East Africa Company, according to press re- 

 ports, has decided to spend $15,000,000 in building a railroad from 

 Tanga to Karagwe. Tanga is a little seaport about fifty miles 

 north-west of Zanzibar, and Karagwe is distant from the starting 

 point about 625 miles. It is the country of the good old King Ru- 

 manika, who so charmed both Speke and Stanley that they cred- 

 ited him with most of the virtues, and pictured his country as an 

 African paradise. The proposed railroad, by starting from Tanga. 

 will avoid the hard climb up the Usagara Mountains. It will 

 doubtless run almost due west to Tabora, the centre of things in 

 inner East Africa, and will then strike north and north-west to 

 Victoria Nyanza and Karagwe, which is within a hundred miles 

 of the western boundary of Germany's possessions. 



— The manuscript of the annual report of the Ohio experiment 

 station was placed in the hands of the State printers in January, 

 but the press of other work has crowded it back, so that it is only 

 now being printed. The report contains a summary of the year's 

 experiments, the full reports of which have been published in 

 bulletins issued during the year. Among the subjects under in- 

 vestigation have been : potatoes, including trials of varieties, use 

 of fertilizers, size of seed; commercial fertilizers, including trials 

 on corn, wheat, and oats at the station and on farms in various 

 sections of the State; experiments with corn, oats, and wheat, in- 

 cluding tests of varieties, quality of seed, date of planting, and 

 methods of culture ; experiments in the control of insects affect- 

 ing fruits, vegetables, and field crops; experiments in the control 

 of fungus diseases of plants, as smuts, rusts, mildews, fruit rots, 

 etc. ; experiments with many varieties of fruits and vegetables, 

 and investigations in some of the diseases of animals. The publi- 

 cations of the station for the year are, its regular bulletin, of about 

 260 pages; the annual report, some 60 pages; and a technical 

 bulletin, of 100 pages, intended primarQy for the use of other sci- 

 entific workers. All are illustrated, and all are distributed free of 

 cost to all persons in Ohio who are interested in agriculture or 

 horticulture. Applications should be addressed to Experiment 

 Station, Columbus, O. 



— In the journal of the Elislia Mitchell Society, Mr. Atkinson 

 calls attention to two new cases of protective mimicry in spiders. 

 A Cyrtaraclme takes shelter in summer and autumn under leaves, 

 where it has absolutely the aspect of a small univalve mollusc, 

 which is extremely abundant, and which often fixes itself in an 

 analogous position. The second example is found in a small spi- 

 der, Thoniisus aleatorius, which is remarkable for the length of 

 its fore-legs, the hind ones being, on the contrary, very short. 

 This spider, which lives upon grasses, ascends the culm, stops 

 suddenly, and disappears from sight. It suffices to fasten itself 

 to a spike by its bind- legs, and to bring together its fore-legs, ex- 

 tended, and form an angle with the culm in such a way as to 

 make itself nearly undistinguishable from the spikelets. 



— Ultramarine has long been a chemical puzzle, alike in its 

 constitution, the cause of its color, and the vicissitudes of its 

 manufacture, but now, says Industries, there is reason to suppose 

 that one of these questions is in a fair way to be definitely solved. 

 Some time ago it was suggested that the color of ultramarine was 

 due to the presence of an allotropic modification of the element 

 sulphur, a substance capable of many vagaries. Mr. F. Krapp 

 lias recently pursued the former line of inquiry by investigating 

 the so-called " black sulphur " of Magnus, which he finds to be 

 not sulphur only, but a mixture of a certain modification of sul- 

 .phur with a compound containing both sulphur and carbon. 

 This modified form of sulphur by mere subdivision gives a blue 

 color to the substance used to subdivide it, and there appears to be 

 little doubt that ultramarine simply consists of a basis of colorless 

 silicates impregnated with blue sulphur, resulting from the sodium 

 sulphide formed in the ordinary course of manufacture. As blue 

 sulphur in a state of isolation is unstable, and quickly passes into 

 the yellow variety, it is easy to understand that on decomposing 



the colorless base by means of an acid, the sulphur itself under- 

 goes change, and ultramarine as a pigment ceases to exist. Mr. 

 Krapp suggests that this same modified form of sulphur may play 

 a part in the production of vulcanite, and that the blue color of 

 certain blast-furnace slags may be due to it. In any case, sulphur 

 which boils at a temperature far above 440 C, whose vapor is 

 colorless, which oxidizes to sulphur dioxide without visible com- 

 bustion, and which itself is moreover blue, is a body sufiiciently 

 remarkable to warrant further research. 



— It is more than probable, says Iron, that the Egyptains were 

 in the habit of transporting vessels overland across the Isthmus of 

 Suez, and tradition records that twenty-three centuries ago a true 

 ship-railway, with polished granite blocks as rails, existed and 

 was worked across the Isthmus of Corinth, where the construction 

 of a ship-canal has been projected. In 1718 the well-known 

 Count Emanuel Swedenborg constructed a road and " machines " 

 for carrying laden vessels from Stromstadt to Iddefjord, in 

 Sweden, a distance of fourteen miles across a rough country, and 

 the successful use of this work by Charles XII. during the siege of 

 Frederikshall led to Swedenborg being regarded not only as a 

 national benefactor, but as a mechanician of no mean ability, for 

 at least a century after his death. 



— The census of British India was taken on Feb. 26 by nearly 

 a million enumerators. According to the London Times, the pop- 

 ulation was found to be nearly 286,000,000, of whom 220,500,000 

 live in British territory, and 65,500,000 under feudatory govern- 

 ments. The increase during the past decade has been 26,000,000, 

 or 29,000,000 if newly acquired districts be included. The density 

 of population is 474 to a square mile in Bengal, 442 in the North- 

 western Provinces, and 248 in Madras. In Sind the growth of 

 population has been very marked. Burmah has also made rapid 

 progress, owing to the abundance of land ready for new settlers, 

 and Lower Burmah is now as densely peopled as Portugal. As re- 

 gards the towns, Calcutta now stands first and Bombay second, 

 but changes in town areas and errors in the preliminary report 

 render it impossible to give an accurate comparison of urban 

 populations at present. 



— An interesting report, by Mr. Campbell, of the British Con- 

 sular Service in China, has been issued by the British Foreign 

 Office. According to Nature, it is the record of a journey of over 

 1,300 miles in districts in northern Corea, many of which have 

 never before been visited by Europeans. Mr. Campbell started 

 from Seoul, the capital, and crossed the peninsula to the treaty 

 port of Won-san (Gensan), and thenje pursued his way along the 

 east coast around Broughton Bay, whence he turned north-east- 

 ward, crossing the Yalu Eiver to PSik-tu-San, known to Europ- 

 eans as the Long White Mountain, and already visited by Messrs. 

 James, Fulford, and Younghusband. The return journey was 

 partly over the same ground, but on arriving at Won-san Mr. 

 Campbell recrossed the peninsula, and so made his way to Seoul. 

 Besides the ordinary record of this joux-ney Mr. Campbell gives a 

 great amount of information on various subjects connected with 

 Corea. The chief amongst these is a most interesting section on 

 the prevalence of Buddhism in the peninsula, and one on the agri- 

 culture and productions. He gives a good deal of information in 

 regard to the geography of northern Corea, and also of the gold 

 production of the country. That Corea contains gold-bearing 

 strata has long been known through the export of gold-dust from 

 the ports, but from Mr. Campbell's i-eport it appears that gold- 

 flelds do exist in considerable numbers, and that some of them are 

 worked with the imperfect native methods. There seems no 

 doubt that, if circumstances were favorable to the proper scien- 

 tific working of the Corean gold-fields, the country would be one 

 of the principal producers of the precious metal in the world. 

 Education in the country seems to be at a very low ebb, and is 

 confined to a knowledge of Chinese. All energy and enterprise is 

 crushed out by an all-pervading tyrannical ofl[icialism, and poverty 

 and squalor are universal. 



— O. C. Charlton, late of Ottawa, Kan., has been appointed 

 professor of natural sciences in the Texas Normal College at 

 Denton. 



