July 28, 1898] 



NATURE 



303 



sterilising and sterilisable poisons in virtue of which {e.g.) the 

 sting of one particular family of hymenoptera confers immunity 

 against the sting or bite of one particular group of animals ? 



Although volcanic flames have been seen and described by 

 many writers, their existence has been doubted by others. 

 Special interest thus attaches to the outbursts of flame which 

 occurred on Vesuvius in April last, and which are dealt with in 

 two papers — one by Prof. E. Semmola in the Rendiconto of the 

 Naples Academy, the other by Prof. V. Matteucci in the Atti 

 del Lincei. From the former paper it would appear that this rare 

 phenomenon may have been caused by the falling in of a part of 

 the crater wall, and consequent blockage of the orifice, the pent- 

 up gases becoming heated until a chimney was formed through 

 which they escaped in flames. Prof. Matteucci's paper con- 

 cludes with the following summary of the principal points : (i) 

 The greater part of the aeriform substances evolved from 

 volcanic magma has the power of producing flames. (2) The 

 small flames in the crater of Vesuvius were of longer duration 

 than the large ones ; these latter did not last without intermission 

 for more than 19 or less than 15 days, and ultimately became 

 small and quiescent like the others. (3) The complex pheno- 

 menon, of which the flames were one of the most interesting 

 features, seems only comparable with that described by Sir 

 Humphry Davy. It has not been reproduced, or, at any rate, 

 has not been noticed on Vesuvius for eighty-four years. (4) The 

 spectrum produced by these flames is continuous, like that 

 •observed by Libbey in the incandescent lavas, also with flames, 

 •of Kilauea. 



Prof. Villari, writing in the Aiti dei Lincei, shows how 

 the shadows of Rontgen rays, produced by different vacuum 

 tubes, can be compared by photography. The shadows in 

 question were produced by a circular leaden disc fixed some 

 little distance in front of the plate, a cross of lead being placed 

 in contact with the plate in order to facilitate comparison of the 

 darknesses of diff'erent parts of the shadow. Prof. Villari found, 

 and his illustrations show, that the shadow of a body intercept- 

 ing the radiations from a focus tube is surrounded by a kind of 

 penumbra several millimetres wide, ending abruptly at the out- 

 side and darkening rapidly towards the centre of the umbra. 

 When a Crook es' tube is used, the umbra terminates in a clearly 

 defined edge ; near the edge, within the umbra, there is seen a 

 black line or fringe ; outside the umbra there is a pale penumbra 

 several millimetres wide, fading away outwards, and followed 

 by a bright ring indicating increased radiation. These two 

 fringes, the dark and the light, resemble those of diffraction. 

 The central umbra seems to gradually darken from the periphery 

 to the centre, probably owing to deflection of the rays into the 

 shadow produced by the opaque intercepting body. 



A BRIEF memoir on the geology of the country around 

 Bournemouth, by Mr. Clement Reid, has just been issued by 

 the Geological Survey, in explanation of the new series map, 

 Sheet 329. The main points of geological interest are de- 

 scribed, including the pipe-clays of Poole, the plant-beds in 

 the Bournemouth cliflTs, and the richly fossiliferous clays and 

 sands of Barton. The price of this little memoir is 4^., and it 

 is illustrated by figures of some of the characteristic fossils 

 found in the neighbourhood of Bournemouth. 



It is announced that the Trustees of the British Museum are 

 about to issue a facsimile of the famous Rhind mathematical 

 papyrus, which deals with such subjects as the elements of 

 geometry and the theory of fractions. The work was prepared 

 for publication several years ago by the late Dr. Samuel Birch, 

 but has since been revised, and a special introduction to it has 

 been written by Dr. Budge. 



NO. 1500, VOL. 58] 



A Flora of the Ardennes, by M. A. Callay, is about to 

 be brought out under the auspices of the Society of Natural 

 History of the Ardennes. It will be published at Charleville by 

 the Society. 



The fossil and recent genera of Eurasian Dreissensida have 

 been figured by M. N. Andrusov in a series of twenty photo- 

 type plates ("Travaux de la Soc. des Naturalistes de St. Peters- 

 bourg," vol. XXV.). The genera include Congeria Dreissensia 

 and Dreissensiomya. 



The U.S. Department of Agriculture has issued a Bulletin 

 (No. 16) on American ginseng, its commercial historj', pro- 

 duction, and cultivation, by Mr. Geo. V. Nash. The plant so 

 called is Panax quinquefolium, belonging to the Araliacese. At 

 one time in great repute as a sovereign remedy for constitutional 

 weakness, &c. , the medicinal use of ginseng is now abandoned 

 except as a demulcent. 



A NEW edition of Mr. H. G. Wells's " Text-book of Zoology " 

 has been published by the University Correspondence College 

 Press. The work is more particularly intended for students 

 preparing for examinations of the University of London, and 

 as such it has met with success. The new edition follows the 

 plan and method of the original volume, which appeared about 

 five years ago, but a large part of the text has been rewritten 

 by Mr. A. M. Davies, whose name now appears on the title- 

 page as joint author with Mr. Wells. The preface states: " Only 

 one chapter in the book remains practically unaltered from the 

 first edition, so that while the credit for the general plan of the 

 work belongs to Mr. H. G. Wells, no responsibility attaches 

 to him for any part of the present book." New diagrams have 

 been inserted, and they are remarkably clear and instructive. 



In vol. iii. No. 4 of the Records of the Australian Museum, 

 illustrated descriptions appear, by Mr. W.J. Rainbow and Mr. 

 C. Hedley respectively, of a new Araneiad, from Cooktown, 

 and a new Bivalve, Lima alata, from Santa Cruz. 



A SPECIAL number of the Middlesex Hospital ybwrMO!/, which 

 has just come to hand, contains, in addition to the usual 

 notes, information respecting the various institutions in 

 connection with the hospital, &c., the beginning of a very 

 interesting account, by Dr. A. Coupland, of "The Story of the 

 Middlesex Hospital." The article is illustrated by several 

 figures of the hospital at different stages of its existence, and 

 a reproduction of a photograph of seventeen members of the 

 staff'in 1865. Among the number is to be found Prof Burdon 

 Sanderson, F.R.S., at that time an assistant physician. 



The additions to the Zoological Society's Gardens during the 

 past week include a Naked-footed Owlet (Athene noctua), 

 European, presented by the Hon. Walter Rothschild ; a Bridled 

 Wallaby {Onychogale frenata) from Australia, two Coquerel's 

 Lemurs (Cheirogaleus coquereli) from Madagascar, a Glass 

 Snake {Ophiosatirus apus), a Back-marked Snake (Coluber 



scalaris), a Snake (Tropidonotus, sp. inc.), European, ten 



Algerian Tortoises ( Testudo ibera) from the Caucasus, nineteen 

 Saddle-backed Tortoises ( Testudo ephippium) from the Duncan 

 Islands, Galapagos Group ; thirty-three South Albemarle Tox' 

 toises (Testudo vicina) from the Albemarle Islands, Galapagos 

 Group ; four Speckled Terrapins (Clemtnys guttata), thirty- 

 seven Painted Terrapins (Chrysemys picta), two American Box 

 Tortoises (Cistudo Carolina), a Stink-pot Terrapin (Cinosternon 

 odoratum), two Alligator Terrapins (Chelydra serpentina) from 

 North America, deposited ; a Graceful Ground Dove (Geopelia 

 cuneata), two Peaceful Ground Doves {Geopelia tran^ui/la) from 

 Australia, purchased. 



