May 3, 1888] 



NATURE 



17 



j when furious waves with an immense comb were approaching 

 they were deprived of their power to do harm by "a patch of 

 oil no larger than a dining-room table." 



Another interesting mineral synthesis has just been effected 

 by M. Dufet. Native di-calcium arsenate,, pharmacolite, occurs 

 very sparingly upon the known parts of the surface of our globe, 

 and is so rarely found in well-defined crystals that M. Des 

 Cloizeaux has only just completed his investigation of its 

 mineralogical and optical properties. Generally it is found in 

 the form of silky fibres, but is at times met with in perfect 

 monoclinic prisms of pearly lustre and frequently possessing a 

 pink tint. M. Dufet has succeeded in producing these beautiful 

 crystals by a very ingenious method. Two concentric vases, 

 the outer containing nitrate of lime and the inner di-sodium 

 arsenate, were filled with water, and so arranged that very slow 

 diffusion occurred between the two liquids. The conditions of 

 Nature were evidently very closely imitated, for the very gradual 

 precipitation thus brought about resulted in the formation of 

 groups of crystals, exactly resembling those of pharmacolite. 

 Goniometrical measurements showed that they belonged to the 

 monoclinic system ; and the close approximation of the fundamental 

 angles to those of the mineral given by Haidinger and Schrauf, 

 and especially the still more remarkable closeness to the values 

 just arrived at by M. Des Cloizeaux, leave no doubt as to the 

 identity of the artificial with the natural. The chemical analysis 

 of M. Dufet's crystals leads to the formula HCaAs0 4 + 2H 2 0, 

 and it thus becomes chemically as well as physically isomor- 

 phous with brushite, the corresponding phosphate of calcium, 

 HCaP0 4 +2H 2 0. This result clears up the discrepancy between 

 the acknowledged formula of the latter mineral and that given 

 by older mineralogists for pharmacolite, 2HCaAs0 4 + 5H 2 0. 

 The number of minerals which have now been reproduced in 

 the laboratory must be very considerable, and every day the 

 likelihood is increasing that those noble species which have for 

 ages been prized as gems may discover the secret of their 

 formation to some indefatigable worker. Rubies and sapphires 

 have already yielded, possibly the diamond may not prove 

 refractory much longer. 



A valuable paper, describing a new method of extraction 

 of the alkaloids from Cinchona bark by cold oil, as used at the 

 Government Cinchona Factory in Sikkim, was lately drawn up 

 by order of the Lieutenant-Governor of Bengal, and has now 

 been issued. Dr. King, the Superintendent of the Sikkim 

 Plantation, carried on a long series of experiments on an acid 

 and alkali process of manufacture, by which he succeeded in 

 producing an excellent quinine. He never, however, succeeded 

 in recovering much more than half of the amount contained in 

 the bark on which he operated. The acid and alkali process 

 had, therefore, to be abandoned, as wasteful and inefficient. 

 A process depending on the maceration of the bark in spirit 

 was next tried, but, after much experiment, it was in turn aban- 

 doned. During a visit which Dr. King paid to Holland in 

 1884, he obtained some hints as to a process of extraction by 

 means of oil. Benefiting by the advice of some chemical 

 friends, Mr. Gammie, the resident manager in Sikkim, has been 

 able to perfect this process, with the result that the whole of the 

 quinine in yellow bark can be extracted in a form indistinguish- 

 able, either chemically or physically, from the best brands of 

 European manufacture. This can be done cheaply, and the 

 Bengal Government has caused an account of the matter to be 

 printed, in order that private growers of Cinchona may be 

 enabled to take full advantage of the process, and that a 

 permauent reduction in the price of quinine may ensue. 



The Trustees of the Indian Museum, Calcutta, have issued a cir- 

 cular announcing that they have had under their consideration the 

 means whereby a useful scientific examination of the insect-pests 



of India can be best effected. Bearing in view the great economic 

 importance of the investigation, they have directed the first 

 assistant, Mr. E. C. Cotes, to consider it an essential portion of 

 his duties, and have instructed him to communicate with persons 

 interested in the subject, and likely to aid the inquiry, in order 

 to collect materials which may form a sufficient basis for really 

 scientific conclusions. Mr. Cotes will gradually record the 

 entire life-histories and practical methods of dealing with the 

 principal insect-pests, publishing from time to time, as materials 

 accumulate, the information collected, and distributing it to 

 those interested. Those who live in the districts where the 

 insects occur, and have actual experience of the pests, are in- 

 vited to send to Mr. Cotes accounts of facts they have observed ; 

 and the circular includes a full statement of the points upon 

 which information is wanted. 



Readers interested in the science and practice of forestry 

 will be interested in the perusal of a Report by the American 

 Consul at Mayence, on Forest-Culture in Hesse, contained in the 

 January issue of the Consular Reports of the United States. 

 The writer discusses the organizations and functions of the 

 department having the care of forests, the duties of the various 

 classes of officials employed in forest-cultivation, the economical 

 results of the system pursued, the course of instruction followed 

 in the schools of forestry, the organization and methods of the 

 institution for experimental forestry, and the degree and amount 

 of control assumed by the State over private forests. The 

 Report is exceedingly detailed, and is practically a hand- 

 book of forestry as practised in the Grand Duchy. 



Prof. Blanchard, the well-known entomologist, has just 

 published in Paris a book on "La Vie chez les Etres animes," 

 in which he discusses Darwinism at length, but in a very 

 incomplete manner, and of course in a hostile spirit. 



The address delivered by Mr. A. D. Michael, President of 

 the Quekett Microscopical Club, on the 24th of February last, 

 is printed in the Club's Journal, and has also been issued 

 separately. The subject is ' ' Parasitism. " 



Prof. Henry Drummond has in the press a new book, 

 "Tropical Africa," which will be published immediately by 

 Messrs. Hodder and Stoughton. It will contain an account of 

 the author's recent travels in Central Africa, with one or two 

 chapters of natural history. 



Mr. Lewis, of Gower Street, will publish immediately a 

 volume of " Physiological and Pathological Researches," by 

 the late T. R. Lewis, F.R. S. (elect). The work is edited by 

 Sir William Aitken, F.R.S., G. E. Dobson, F.R.S.,and A. E. 

 Brown, and contains five maps, forty-three plates, including 

 chromj-lithographs, and sixty seven wood engravings. 



At the meeting of the Institution of Civil Engineers on 

 Tuesday, April 24, Mr. E. B. Ellington read a paper on the 

 distribution of hydraulic power in London. In the course of 

 his remarks he took occasion to refer to the large extent to 

 which lifts are now used, and he considered it necessary, he 

 said, to urge the importance of securing the greatest possible safety 

 iti their construction by the general adoption of the simple ram. 

 Suspended lifts depended on the sound condition of the ropes or 

 chains from which the cages hung. As they became worn and 

 untrustworthy after a short period, it was usual to add safety 

 appliances to stop the fall of the cage in case of breakage of 

 the suspending ropes, but these appliances could not be expected 

 to act under all circumstances. 



Miss Marie Brown, well known for her researches on the 

 earliest colonization of North America by the Scandinavians, 

 has presented a petition to the United States Congress urging 

 that steps should be taken to secure a thorough search of the 



