3Iay 30, 1878] 



NATURE 



^2>Z 



thus be made to hear the voice, music," &c. A diagram is pub- 

 lished in the Mail, showing the working of the telephone as 

 described. 



The cultivation of the opium poppy {Papaver somniftntni), 

 which has hitherto been exclusively confined to the east, bids fair 

 to become thoroughly established and remunerative in Eastern 

 Africa. Seeds of the best kinds have been imported from 

 Malwa into Mozambique, where 50,000 acres of uncultivated 

 State land have been granted to a company, with a capital of 

 178,000/., for the purpose of cultivating and trading in opium. 

 Besides the grant of land, the company also receives from the 

 State " the exclusive right for twelve years to export opium free 

 of duty through all the custom-houses of the province." It is 

 satisfactory to learn that the poppy plants are thriving, and the 

 fruits are reported to be larger than those produced in the best 

 opium districts of India. 



A Russian medical paper draws attention to Sarracenia pur- 

 purea as a remedy for gout, administered in the form of a 

 powder in the proportion of one or two teaspoonfuls morning 

 and evening. 



The thirty-second meeting of German philologists and peda- 

 gogues will take place at Gera at the end of September. 



Herr Ferdinand Noll, of Brandenburg, has presented to 

 the International Postal Congress, now sitting at Paris, the 

 drawings and descriptive -plans of a decimal clock as well as two 

 models of the clock itself. Its object, as its name implies is to 

 introduce a division of time on the decimal system in accordance 

 with that already in use for measures, weights, and moneys. 

 Herr Noll therefore divides his dials into twenty hours and gives 

 100 minutes to the hour, each minute having fifty seconds, and 

 each second fifty "tertien." Dr. Forster, the Director of the 

 Berlin Observatory, gave a very favourable opinion of the inven- 

 tion when submitted to him two or three years since. 



A French agricultural paper announces the discovery of an 

 extremely simple and cheap means to protect houses from being 

 struck by lightning. This consists merely in bundles of straw 

 attached to sticks or broom-handles and placed on the roofs of 

 houses in an upright position. The first trials of this simple 

 apparatus were made at Tarbes (Hautes Pyrenees) by some intel- 

 ligent agriculturists, and the results were so satisfactory that 

 soon afterwards eighteen communes of the Tarbes district pro- 

 vided all their houses with these bundles of straw, and there 

 have been no accidents from lightning since in the district. 



The Emperor of Austria has conferred the Cross of the Order 

 of Francis Joseph upon the two well-known African travellers, 

 Drs. Georg Schweinfurth and Gerhard Rohlfs. 



The large botanical library left by the late Prof. A. Braun, 

 formerly director of the Berlin Botanical Gardens, is now being 

 sold by Messrs. List and Francke, of Leipzig. 



Our readers will be glad to learn that Sir William Thomson 

 and Prof. Tait have nearly completed for publication the first 

 part of the new edition of their ^work on natural philosophy, 

 which will be brought out very shortly by the Cambridge 

 University Press. 



No less than twelve separate subterranean shocks are re- 

 ported from Ancona as having occurred between May 9 and 12. 



The Government of Uruguay intends to construct a railway 

 which will unite Uruguay with the Province of Rio Grande 

 do Sul, in which many thousands of colonists are settled. The 

 line is to begin on the right bank of the Quarahim River, and is 

 to extend as far as the town of Uruguayana. On the Quarahim 

 River this railway will join the line in course of construction 

 between Salto and Santa Rosa, which is already finished and in 

 use as far as Jacuhi (some 300 miles), and which in turn corre- 

 sponds with the line between Salto and Fray Bentos, where the 

 great Saladeros (slaughter-houses) of the " Liebig Company " 



are situated, at which over 1,000 head of cattle are killed daily 

 to make the well-known "Liebig Extract of Meat." 



Mr. J. M. Wilson, of Rugby, has in the press a treatise on 

 geometry written to correspond with the Syllabus of the Geo 

 metrical Association. The work will be published by Messrs. 

 Macmillan and Co. 



Messrs. Macmillan and Co. are preparing for publication 

 a treatise on the nature and origin of coal and the extent of 

 the supply in this country, written by the Professors of the 

 Yorkshire College of Science, Leeds. The authors propose to 

 sketch out the state of the country at the time when coal 

 was coming into being and the processes by which it was 

 formed ; next to deal with the present, and give an account of 

 the methods of working coal and some of the uses to which it is 

 now being put ; lastly, to endeavour to forecast the future and 

 speak of the probable duration of oiu- coal supply. The work 

 will be edited by Prof. T. E. Thorpe, F.R.S. In it Prof. 

 Riicker will treat the subject from the physicist's point of view ; 

 Prof. Miall will discuss its natural history ; Prof. Green will 

 take the geology of the question ; Prof. Thorpe the chemistry ; 

 and Prof. Marshall will write on the economics of coal. 



In a recent paper in VAeronaute, Col. Laussedat gives the 

 results of experiments made by a Commission appointed by the 

 French Minister of War. For Captive Balloons it is absolutely 

 necessary to employ the best silk and cordage, which, with the 

 least weight, offers the greatest guarantee of durability. After 

 much research a special varnish has been found which renders 

 the aerostat impermeable to gas. Instead of numerous ropes 

 held by men as in former military ballooning, a single cable has 

 been adopted to work by a simple but secure capstan. Capt. 

 Renard has discovered a rapid and economical new process of 

 manufacturing hydrogen. For Postal Balloons Capt. Renard 

 also has devised a secure and easily-worked valve. A liquid 

 instead of a solid ballast has been resolved on, and a fluid is 

 being sought which will not congeal in the low temperatures of 

 the upper atmosphere. The valve and the ballast may work 

 automatically and maintain the balloon at any given height. 

 Among the methods of stopping the balloon experimented on 

 are the javelin anchor of Meusnier and a sort of iron arrow 

 devised by Capt. De la Haye. For Directable Balloons the 

 principles which guided Dupuy de Lome have, for the most part, 

 been adopted by the Commission. That experimenter found 

 that with an engine of eight horse-power turning a screw he 

 could deviate from the direction of the wind by a considerable 

 angle, with ordinary winds, and even travel, with reference to 

 the earth, in all directions which it would be wished to follow. 

 The Commission, however, instead of placing the screw in the 

 car, at a great distance from the point of application of resist- 

 ance of the air, have constructed the balloon so that the screw 

 may work in the very centre of the aerostat. 



Those familiar with the treasures of the Biblioth^que Na- 

 tionale in Paris will appreciate the importance of a law lately 

 laid before the French Chamber by the Minister of Public 

 Instruction, providing for the demolition of all buildings 

 adjoining the library, in order to insure its complete protection 

 from danger by fire. The great building will in the future be 

 entirely surrounded by an open space laid out in gardens and 

 walks. 



The Paris Jardin d'Acclimatation has just received from the 

 Seychelles Islands three of the largest tortoises known. The 

 heaviest weighs 187 kilogrammes and is ij metre in diameter. 



At the meeting of the Institution of Surveyors on the 13th 

 May, Mr. R. W. Peregrine Birch read an important paper on 

 the use of sewage by farmers. Mr. Birch has collected a 

 considerable quantity of statistics on this unsavoury but im. 

 portant subject, firom which the following conclusions are 



