June 19, 1885.] 



SCIENCE. 



511 



The present part contains the latest methods, and 

 cites the literature very fully, and may be bought 

 separately by those who wish. Part second will 

 treat of the cell and the structure of unicellular ani- 

 mals ; part third, of the ectoderm and its derivatives 

 in the metazoa; part fourth, of the entodermal and 

 mesodermal organs, — the whole to make a volume 

 of some six hundred and fifty pages. 



— According to the Colonies and India, Baron F. von 

 Miiller, K.C.M.G , has issued, under the auspices of 

 the Victorian government, a second supplement to 

 his systematic census of Australian plants. It ap- 

 pears from the information now published, that, 

 whilst the known plants of Australia and Tasmania 

 are about 9,000, they occur in the following propor- 

 tions in the respective colonies: viz., western Aus- 

 tralia, 3,455 ; Queensland, 3,457; New South Wales, 

 3,154; northern Australia, 1,829; Victoria, 1,820; 

 South Australia, 1,816; and Tasmania, 1,023. The 

 progress of botanical discovery in Australia within 

 the last quarter of a century has been very marked; 

 and the colonies are mainly indebted to Baron Miiller 

 for this result. He, with the late Mr. Bentham, pre- 

 pared and published the seven volumes of the 'Flora 

 Australiensis.' 



— Dr. Fischer, who lived for seven years as a doc- 

 tor in Zanzibar, has published a book on the colo- 

 nization of tropical Africa, called ' More light on 

 a dark quarter of the world ; ' also a report of his 

 journey from Pangani to Lake Naewascha, under- 

 taken for the Hamburg geographical society. 



— According to Nature, the British consul at Leg- 

 horn, in his report for the past year, makes some in- 

 teresting observations on coral in the Mediterranean. 

 Some centuries back the Mediterranean coral fish- 

 eries were carried on exclusively by the Spaniards, 

 and the principal establishments engaged in the man- 

 ufacture of coral ornaments were in the hands of 

 Jews residing in Spain. Towards the close of the 

 sixteenth century, to escape the persecutions to which 

 they were exposed, a large number of these mer- 

 chants removed to Leghorn, in order to enjoy the 

 secure asylum afforded by the liberal enactments of 

 Ferdinando di Medici. Crews were obtained from the 

 Neapolitan coast, principally from Torre del Greco: 

 hence this place, at an early period, became the chief 

 seat of the coral fishery; and most of the boats en- 

 gaged in it are still fitted out at that port, although 

 the manufacture of coral ornaments and beads is 

 carried on principally at Leghorn and Genoa. These 

 ornaments are met with in almost every part of the 

 world ; and in many countries, even in Europe, coral 

 is believed to be possessed of a peculiar charm. In 

 Asia and Africa it is regarded with a sort of religious 

 veneration, while in India it is largely used for the 

 adornment of corpses when prepared for cremation. 

 But the present situation of the coral trade is disas- 

 trous. In 1880, a coral bank several kilometres in 

 length was discovered near the island of Sciacca, on 

 the coast of Sicily, and consequently the yield of raw 

 material has been far in excess of the demand, and 

 the reef is still very far from being exhausted. A 



great depreciation in value has ensued, and, as a 

 consequence, an extensive trade has sprung up in 

 coral with Africa, where the natives now jmrchase 

 coral ornaments in place of glass beads of Venetian 

 and German manufacture. The raw coral comes 

 from Naples, and is worked at Leghorn by women 

 into beads, British India and Egypt being the chief 

 customers for them. 



— Mr. Shelford Bidwell has read a paper before the 

 Royal society, on the changes produced by magneti- 

 zation in the length of rods of iron, steel, and nickel. 

 He finds that the length of an iron rod is increased 

 by magnetization up to a certain critical value of the 

 magnetizing force; and, if that is passed, the elonga- 

 tion is diminished in proportion as the magnetiz- 

 ing force increases. The amount of the maximum 

 elongation appears to vary inversely as the square 

 root of the diameter of the rod. In soft steel, mag- 

 netization produces elongation; and, with hard steel, 

 the critical value of the magnetizing force becomes 

 very high. In soft steel a temporary elongation, once 

 produced, may be maintained by a magnetizing force 

 too small in itself to produce any elongation. Nickel 

 continues to retract with magnetizing forces far ex- 

 ceeding those which produce the maximum elonga- 

 tion of iron. The greatest observed retraction of 

 nickel is more than three times the maximum 

 observed elongation of iron, and the limit has not 

 yet been reached. 



— Prof. H. A. Hazen has prepared a signal-service 

 note (no. xx.) on the thunder-storms of May, 1884, in 

 which he gives a brief statement of the results ob- 

 tained from the volunteer observations on these storms, 

 gathered on special cards from persons in all parts of 

 the country. It is illustrated by maps for May 18 and 

 19, showing the advance of the thunder-storm area for 

 these days. The conclusions presented are, 1°, hail- 

 falls occur ordinarily with a pressure much below the 

 normal, and in a position two or three hundred miles 

 south-east of the centre of barometric depression 

 (cyclonic centre); 2°, thunder-storms advance from 

 west to east and south-east, generally accompanying 

 a cyclonic depression in its south-east quadrant, four 

 or five hundred miles from the centre ; 3°, their ac- 

 tion seems to die down at night, and begin again in 

 the morning, and often spreads in a fan-shape to 

 south-east and east; 4°, the velocity of the thunder- 

 storm's advance is greater than that of the accompany- 

 ing cyclonic depression. Description of the simple 

 method of observation is added, and it is stated that 

 more observers are still desired. Franked cards for 

 mailing records will be supplied on application to the 

 chief signal officer of the army, Washington. 



— Mr. E. W. Maunder, assistant in charge of the 

 spectroscopic work of the Royal observatory, Green- 

 wich, is giving, in the current numbers of the Obser- 

 vatory, a paper on the motions of stars in the line of 

 sight, as determined by spectroscopic methods. He 

 remarks, that if the definition attributed to Bessel 

 be a correct one, — that ' astronomy is the study of the 

 movements of the heavenly bodies,' — spectroscopy 

 had no claim to be regarded as a branch of astronomy 



