April 5, iii94j 



NA TURE 



541 



cultures under various conditions. Amongst these the action of 

 heat was investigated, and it was ascertained that the tetanus- 

 filtrite diluted with witer wn deprive! of all pathogenic 

 properties when exposed for one hour to 55° C., but vvhen com- 

 pletely desiccated it was still toxic after biing exposed for one 

 ho ir to 120° C. The action of an electric current on its patho- 

 genic properties was also examined, and they were found to be 

 destroyed after exposure for about two hours to a current of 

 about o'5 amperes. Numerous chemical substances were also 

 investigated. Amongst the gases experimented with, it was 

 found that oxygen, carbonic anhydride and hydrogen produced 

 no appreciable effect even after from ten to fifteen hours' 

 contact. 



Messrs. Saxon and Co. have published a useful little 

 book, entitled "Everybody's Guide to Gardening,"' by Mr. 

 H. H. W arner. 



Dr. T homas Lynn's " Health Resorts of Europe " (Bristol : 

 John Wright and Co. ), being a guide to the mineral springs, 

 climates, mountain and sea-side stations of Europe, has reached 

 a second edition. 



The Calendar of the Royal University of Ireland, for the 

 year 1894, has just been published. The papers set at the 

 examinations in 1893 are published in a separate volume, 

 forming a supplement to the Calendar. 



The Botanical Exchange Club of Vienna has issued an 

 extensive list of specimens of rare plants, which it is ready to 

 exchange or sell. Several new species are also described. The 

 list m.iy be obtained from Herr J. Di'irfler, of I. Burgring 7, 

 Vienna. 



Dr. T. W. Moll, the Director of the Botanic Garden at 

 Groningen, publishes (in French) a list of forty-two species of 

 Papaveraceae grown in the Garden, three of which are probably 

 hybrids. Seeds of a large number of the species are offered to 

 other horticulturists. 



We have received the number of the /otirnal of the Royal 

 Horticultural Society for January. Besides extracts from the 

 Proceedings of the Society and its committees, it contains reports 

 on the growth of a number of garden plants and vegetables 

 at Chiswick, and papers by specialists on various subjects 

 interesting to horticulturists. 



Dr. C. V. Riley, of Washington, has sent us a paper on 

 "Parasitic and Predaceous Insects in applied Entomology," 

 and one entitled "Further Notes on Yucca Insects and Yucca 

 Pollination." The pollination of Yucca Whipplei hy Pro7tttba 

 maculata is described in detail. In another paper he describes 

 two new species of Jlegastismus, a genus of Chalcididce which 

 is essentially parasitic, chiefly on gall-making Cynipida;. 



Mr. a. E. Munby has prepared a pamphlet entitled " Notes 

 on Polarised Light, for Students of Mineralogy," and published 

 by Messrs. Reid, Sons, and Co., Newcastle-on-Tyne. In the 

 twenty-eight pages, of which the pamphlet consists, an elemen- 

 tary description is given of the optical principles utilised in the 

 construction of the polariscope, and of phenomena observable 

 with that instrument used as an adjunct to the microscope. The 

 notes should be of use to elementary students of mineralogy, 

 for they contain clear explanations of the various points con- 

 nected with the classification of crystals according to their 

 optical symmetry. 



Some years ago Liebig wrote to the Royal Agricultural and 

 Commercial Society of British Guiana: "There cannot be a 

 more beautiful and striking exemplification of the genuine 

 British spirit than the disposition shown by the most distin- 

 guished and best-informed men in the remotest parts of the 



NO. 1275, VOL. 49] 



great empire to form themselves into Societies, which have for 

 their object the extension, promotion and application, for the 

 public good, of scientific principles." On March 18, the Society 

 to which these words were addressed attained its jubilee, and in 

 view of this fact a short account of its establishment and work 

 is given in the current number of its excellent journal, Tunehri. 

 In addition to this description, the journal contains a long paper, 

 in which Mr. Edward F. im Thurn details the incidents of one 

 of his journeys into the far interior of Guiana. 



When the Natural History Society of Rugby School was 

 founded in 1867 it was laid down that the objects for which it 

 was established were (i) to work out the natural history of 

 Rugby ; (2) to keep an annual register of all facts connected 

 with natural history observed there ; (3) to assist in the forma- 

 tion of a museum for reference ; (4) to hold meetings for the 

 reading and discussion of papers on scientific subjects. The 

 report just issued by the Society shows that most of the original 

 objects were faithfully carried out during 1893. The members of 

 the botanical section have worked well, and, thanks to their exer- 

 tions, have prepared a useful list of Rugby mosses. In theentomo- 

 logical section, also, good work was done. The report includes 

 an observation list of Rugby Lepidoptera, containing 293 species, 

 of which six are new to the district, and Mr. F. D. Morice con- 

 tributes some additions to his list of Hymenoptera. Up to 

 December of last year he had found upwards of 140 species of 

 Aculeates in the Rugby neighbourhood. Other sections of the 

 Society concern themselves with zoology, archceology, geology, 

 photography, and meteorology. The report not only contains 

 the proceedings of these sections, but also a brief statement of 

 the observations made at the Rugby Observatory, and several 

 papers read at the meetings. We have also received the 

 last report of the Epsom College Natural History Society. 

 Such societies deserve the greatest encouragement, and the 

 only matter for regret is that their work is not found interesting 

 to a larger proportion of the schools to which they belong, 

 instead of being left to a few enthusiasts. 



A DETAILED accouut of his investigations concerning the 

 gaseous fluorides of the simpler organic radicles is contributed 

 by M. Meslans to the March number of the Aiinales de Chimie 

 et de Physique. The fluorides of methyl and ethyl have already 

 been fully described by M. Moissan and other workers, and the 

 fluorides now described are those of the radicles propyl, iso- 

 propyl, allyl, and acetyl, together with the interesting analogue 

 of chloroform, fluoroform, Propyl fluoride may be obtained by 

 reacting with the corresponding chloride, bromide, or iodide 

 upon anhydrous fluoride of silver. The iodide is most con- 

 venient as it reacts at the ordinary temperature, while propyl 

 bromide requires heating to the neighbourhood of 100°, and the 

 chloride to a still higher temperature. The reaction between 

 propyl iodide and silver fluoride may be best carried out in 

 a copper tube immersed in tepid water. The propyl iodide is 

 admitted to the tube already containing the silver fluoride from 

 a dropping funnel, and the gaseous product of the reaction 

 passes upwards through a leaden condensing worm, cooled by 

 iced water, and subsequently through three U-tubes containing 

 fragments of silver fluoride, and finally through a delivery tube 

 to the mercury trough over which the gas is to be collected. 

 The reaction does not simply result in the formation of propyl 

 fluoride and silver iodide. A third substance is produced, a 

 red solid substance which is found to be an iodo-fluoride of 

 silver of the composition Ag.iFI. The amounts of propyl fluoiide 

 and of the latter substance obtained correspond to the equation 



CjH.I + 2AgF ^ CjHjF -f Ag.FI. 



Propjl fluoride is a colourless gas possessing an odour similar to 

 that of the analogous chloride. It barns with a brilliantly lumi- 



