258 



HARDWICKE'S SCIENCE-GOSSIP, 



M. A. Ricco, of Palermo, has invented a veiy 

 original electro-magnet. He rolls a long strip of 

 sheet-iron around a nut of soft iron, placing oiled 

 paper between the different layers of the strip to 

 isolate them. A pole is connected with the nut, to 

 which the inner end of the iron strip is soldered, 

 while the other is connected with the outer end. The 

 current passing through the strip magnetises not only 

 the nut, but also each layer of the strip of iron, which 

 plays the double rdle of conductor and magnetic 

 substance, so that the lines of power produced by the 

 conductor are condensed. It is stated that the power 

 of such a magnet is considerably greater than that of 

 an ordinary electro-magnet. 



A SAD accident has occurred at the Healtheries. 

 Henry Pink, an attendant employed in the dynamo- 

 shed, had one hand on one of the brushes of a 25-arc 

 light Hockhausen machine. By some means he got 

 his other hand on the other brush, or on another part 

 of the machine, with the result that a part of the 

 current passed through his body. His death was 

 not instantaneous, but occurred a few minutes 

 afterwards. 



Large bluish-green topazes, weighing several 

 pounds, each, have been found at Mudgee, New 

 South Wales. 



In its application to carious teeth, creosote is often 

 inconvenient in consequence of its iluidity producing 

 ill effects upon the mucous membrane of the mouth. 

 This may be obviated by giving to it a gelatinous 

 solidity by adding ten parts of collodion to fifteen of 

 creosote. This, besides being more manageable than 

 liquid creosote, also closes up the orifice in the tooth, 

 preventing the access of the air to the dental nerve. 



Stern paddle-wheel gun-boats have been lately 

 built by the French Government for service on the 

 rivers Tonkin and Gaboon. 



A NEW small motor, actuated by explosions of 

 small charges of gun-cotton, has been brought out. 

 It is said to be useful whenever small powers are 

 required. 



On the 22nd of October, Wolfs Comet was 

 observed as follows : right ascension 21 h. 50 m. 

 31 s. ; north declination 6° 24' "2. 



Tuic last part (XX.) of Dr. Lang's "Butterflies 

 of Europe," has just appeared. It deals with the 

 genera Ctenonymphea, Triphysa, Erebia, CEneis, 

 Ypthmia, Pararge, Epinephele, and those of the Hes- 

 peridse, &c., giving detailed accounts of each species. 

 There is also a list of adtlenda. Altogether this is 

 the completest work of the kind yet published, 

 whilst the high finish of the coloured plates raises its 

 artistic merits to the highest rank. A systematic 

 list of European butterflies is given in the present part, 

 and a full index of species, varieties, synonyms, &c. 



The French Commission appointed to inquire into- 

 the nature, &c., of cholera, reject Dr. Koch's "Comma 

 bacillus," and maintain that the blood contains the 

 cholera poison, and that the initial lesion of cholera 

 takes place in the blood. They state that by the 

 hourly examination of the blood of cholera patients, 

 the progress of the malady can be mathematically 

 followed. 



M. Perrey has found a solution of sulphate of 

 copper of the greatest benefit, when applied to vines 

 not more than six years old, in preventing and over- 

 coming mildew. 



A PATENT has been brought out for coating the 

 surfaces of other metals with oxide of copper, which 

 can be varied in their colour. 



Sulphide of carbon is stated to be an antiseptic, 

 and a sure destroyer of all living germs. 



"We recommend all those who are about to get up 

 conversazioni in connection with scientific societies,, 

 to procure a short handbook drawn up for the Chester 

 Society of Natural Science by Mr. C. F. Fish. It 

 sets forth in an admirable manner what to show, and 

 how to show objects illustrating almost every depart- 

 ment of scientific inquiry. 



The volume of the "Smithsonian Report for 1882 " 

 has just been published. It contains, besides the 

 Report, records of recent scientific progress in astro- 

 nomy, geology, geography, physics, chemistrj-, 

 botany, mineralogy, zoology, anthropology, &c. 



ZOOLOGY. 



TheMollusca of Kent, Surrey, and MiDDLji- 

 SEX. — I am now working out the Mollusca of these 

 counties, and am very anxious to obtain all possil'le 

 information on the subject, and local lists from those 

 districts which I have not been able to visit myself. 

 Can any of the readers of Science-Gossip help me 

 in the matter ? Any information whatever relating 

 to the Mollusca of these three counties would be most 

 welcome. — 7'. D. A. Cockcrdl, 51 Woodstock Road, 

 Bedford Park, Chiswick, W. 



The Book-Worm. — In your issue September last 

 there are some remarks about the book-worm. 

 Having had some experience of this excavator in a 

 volume dated 1484, thus exactly 400 years old, I beg 

 to state my conviction that it is identical with 

 the Scolytus which perforates beech-wood. Early 

 books had covers of wood, chiefly of beech-wood, 

 though sometimes of oak. Our very term " book " is 

 derived from the Saxon " boc," beech. Now it is the 

 wood, not the leaves, which is specially the object ot 

 the larva:. In my volume the covers were entirely 

 riddled, and only held together by the leather 



