December 6, 1894] 



MATURE 



131 



The Report of the Botanical Exchange Club of the British 

 Isles for 1893, just received, contains a number of useful and 

 interesting notes on critical and rare British species, the general 

 Kiiliiis, Hittacium, and Polamogitoii coming in for a specially 

 Urge share of attention. It is edited by Mr Jas. Groves. 



The results of the meteorological observations made at the 

 United States Naval Observatory during 18S9, and the mag- 

 netic observations made at the same observatory during 1892, 

 have just reached us. It would be to the advantage of science 

 if the observations could be published without such a long 

 delay. 



The twenty-first annual report of the Geological and 

 Natural History Survey of Minnesota has been received. It 

 embraces statements relating to progress in the strictly 

 geological portion of the Survey. Independent reports will be 

 published upon the botanical and zoological departments of the 

 work. 



The December number of the Geological Magazine contains 

 an account of the life and work of the late Mr. William 

 Topley, F. R. S. , written by Mr. H. B. Woodward, and 

 accompanied by a portrait of the deceased geologist. The 

 memoir is a tribute to a life of unremitting labour in .he cause 

 of geology, and an expression of the high regard in which 

 Mr. Topley is held by all who cherish his memory. 



The Geographical Journal this month gives prominence to a 

 new feature in the way of short summaries of the most recent 

 and trustworthy literature on parts of the world where public 

 interest is concentrated for the time. The regions dealt with 

 are the Waziri country and Madagascar, and in addition there 

 are two special papers of considerable length on Eastern Asia 

 — one by Mr. A. R. Agassiz, on the commercial resources of 

 Manchuria ; the other by Baron von Richthofen, on China, 

 Japan, and Korea. 



Hitherto Brehm's well-known collection of works on 

 natural history, in the Merveilles de ia Naiure series, published 

 by MM. J. B. Bailliereet Fils, Paris, has not comprised a volume 

 on botany. This gap is now, however, to be filled by " Le 

 Monde des Plantes," of which the first part has just appeared. 

 The author of the work is Prof. Paul Constantin. There will 

 be eight fasciculi altogether. When the work is completed 

 its two volumes will run into fifteen hundred pages, and be 

 embellished by two thousand illustrations. Particular attention 

 is paid to the use of plants for food, and in medicine, industries, 

 agriculture, and horticulture. The biological characters are 

 also carefully treated. The work promises to be the best 

 popular botanical work published in France, and therefore 

 6ttingly finds a place in Brehm's series on the wonders of nature. 



Mr. a. S. Ghosh has sent us a slender little pamphlet on 

 "Pedal and Antipedal Triangles," being an attempt to in- 

 vestigate the laws of their evolution. (Calcutta : Patrick Press, 

 1894.) The primitive triangle is considered as obtained from 

 the pedal triangle, and is called its antipedal triangle ; so that 

 what is sometimes called the excentric triangle is the antipedal 

 of the primitive triangle. The whole of the pamphlet, which 

 is a fairly neat piece of work, is merely a solution in cxtemo of 

 a "ten-minute conundrum." 



We have received the Proceedings and Transactions of the 

 Royal Society of Canada, for the year 1892 (vol. x.). The 

 volume contains six papers in the section of mathematical, physi- 

 cal, and chemical sciences. Among these we notice one on the 

 Mexican type in the crystallisation of the topaz, and another 

 11 'jbseivations of sun-spots at the McGill College Observatory. 



lie section of geological and biological sciences contains the 

 presidential address on the diffusion and sequence of the Cam- 

 brian faunas ; and, among others, papers on the artificial propa- 



NO. 1310, \OL. 51] 



gation of marine food fishes and edible crustaceans, and on the 

 correlation of early cretaceous floras in Canada and the United 

 St ites. 



At the inaugural meeting of the fourteenth session of the 

 Institution of Junior Engineers, held on November 16, Mr. 

 Alexander Siemens gave some wholesome advice to young 

 engineers and inventors. In the course of his address, he 

 dispelled the fable about the circumstances which led to the in- 

 vention of the steam engine. According to the popular version. 

 Watt, as a small boy, saw the lid of a tea-kettle move up and 

 down, when the water was boiling, and this suggested to him 

 the construction of the steam engine. As a matter of fact. 

 Watt made himself acquainted with what had been done before 

 (a point altogether ignored in the popular version), and had to 

 work verj' hard before he brought his invention to a successful 

 issue. His example is typical of the true method of progress, 

 and it may be said generally, that in order to approach a 

 problem with the best prospect of success, it is necessary (l) to 

 define, as accurately as possible, the want that exists, or the par- 

 ticular object that is to be attained ; (2) to be well acquainted with 

 the scientific principles which come into play ; (3) to know how 

 the want is met, or the'object attained in practical life ; (4) to 

 find out what proposals have been made by others in the same 

 or in a similar case. A careful attention to these re- 

 quirements will prevent much disappointment and waste of 

 energy. The records of the Patent Office show that one or 

 more of these conditions is frequently ignored. A large class of 

 inventors do not realise that a knowledge of scientific prin- 

 ciples would be an assistance in their efforts ; or if they study 

 science at all, they think they can acquire the necessary 

 knowledge by a short study, and without much trouble. 



A NOTE concerning the synthesis of the chlorides of carbon 

 CjCI, and C^Cl,;, during the preparation of carbon tetrachloride 

 by the chlorination of carbon disulphide at low temperatures, 

 is communicated to the Berichte by Prof. Victor Meyer. It is 

 a well-known fact that at a red heat the vapour of carbon tetra- 

 chloride is dissociated, a portion of the chlorine being liberated 

 and the two chlorides above mentioned being produced. It now 

 appears that this change occurs to some extent at temperatures 

 but slightly elevated above the ordinary. At the chemical 

 works of Messrs. Miiller and Dubois, near Mannheim, carbon 

 tetrachloride is manufactured in large quantities by the 

 chlorination of carbon disulphide at temperatures between 20° 

 and 40°. Each operation is allowed to proceed for several 

 days, and the completion is indicated when the liquid has be- 

 come deeply coloured owing to the formation of sulphur 

 dichloride, SXl.j. The carbon tetrachloride is then distilled 

 ofi, leaving the chloride of sulphur behind. Upon rectification 

 of the carbon tetrachloride a quantity of a higher boiling oil is 

 obtained, the nature of which Prof. Meyer has investigated. 

 Upon fractionation it separates into three constituents, 

 carbon tetrachloride CCIj, the liquid chloride analogous to 

 ethylene CjClj, and the solid chloride CoClj, the so-called per- 

 chlorethane. Excellent crystals of the latter compound are at 

 once obtained practically pure. That a real synthesis of these 

 two latter compounds occurs during the manufacture of carbon 

 tetrachloride at so low a temperature as 20°-40°, is proved by 

 the fact that the carbon disulphide employed is found to be quite 

 pure, except for a mere trace of dissolved free sulphur. Prof. 

 Meyer considers that the two chlorides are produced in 

 accordance with the equations : 



2CS., -I- loCl = CjClj -f 2S.,C1.„ 

 2CS; -H SCI = C2CI4 + 2SXI,. 



The atomic weight of bismuth has been re-determined by Frot 

 Schneider, of Berlin, and the result is remarkable as once more 

 affording exactly a whole number, 20S, as the relative weight of 



