February 23, 1899] 



NA TURE 



397 



About four years ago, Prof. Wilhelm %-on Bezold pointed out, 

 from theoretical considerations, that both winter and night 

 thunderstorms, compared witli summer and afternoon thunder- 

 storms, should be much more frequent on the sea and the coasts 

 than inland, but that this effect could scarcely be expected in 

 the case of sea-coasts where the paths of the cyclones are 

 generally from the land to the sea. The work of Messrs. 

 Mohn and Hildebrandson on Norway and Sweden, and of Dr. 

 Meinardus on the open sea, is in general agreement with this 

 theory, as also are other more or less complete reports for 

 different places. Prof. H. D. Stearns has made a further in- 

 vestigation of the subject, and gives his results in the U.S. 

 Monthly Weather Review. His tables and curves, showing 

 monthly percentages of thunderstorms on coasts and inland in 

 various parts of the world (the British Isles included), establish 

 a general law that the percentage of winter thunderstorms de- 

 creases in p.issing from a coast inland in the general direction 

 of the prevailing cyclonic winds. 



The spectroscopic analysis of minerals is in most cases under- 

 taken by using the electric spark as the heat source for volatilis- 

 ing the substance. Considerable difficulty is experienced in 

 the case of those minerals which are non-conductors, such as the 

 felspars. M. A. de Gramont {Bull, de la Soc. Franc c/e 

 Mineralo^ie, March, April, and May 1898) has overcome this 

 by first mixing some easily fusible salt with the powdered 

 mineral, and then heating the mixture with a Bunsen burner, 

 when the mineral is generally dissolved in the salt, and the 

 electric spark is passed from the mass while molten. In most 

 cases, he uses one or more Leyden jars in the secondary circuit 

 to raise the temperature sufficiently. The salts he finds best 

 adapted are the carbonates of lithium and sodium, chiefly on 

 account of the simplicity of their spectra, which have, of course, 

 to be eliminated from the results before the spectrum of the 

 mineral itself can be mapped. For this purpose he gives tables 

 of the principal wave-lengths in the spectra of these salts, and 

 also of the more commonly occurring simple bodies. He then 

 describes in detail the characteristics of the spectra observed 

 with the non-conducting minerals, of which he has examined 

 some twenty-five different specimens. 



From a paper dealing with the mica mines in Bengal, con- 

 tributed by Mr. A. Mervyn Smith at the meeting of the Insti- 

 tution of Mining and Metallurgy on February 15, it appears that 

 the industry is a very ancient one, the methods of mining the 

 mica and preparing it for market having been in use for 

 centuries. The mica occurs in pegmatite veins running through 

 foliated rocks, and is taken out from open cuts made in the 

 decomposed granite, and abandoned as soon as solid rock is 

 reached. The miners are a local tribe called Bandathis, men, 

 women and children all working at the mines in the dry months 

 when there is no agricultural work in the fields to be done. The 

 books of mica are chiselled out, the work being aided by large 

 fires when the pegmatite is hard, and split into sheets of about 

 one-eighth of an inch in thickness. The rough edges are then 

 trimmed, and the sheets sorted into four qualities and several 

 sizes; the best "ruby" mica, which is unaffected by high 

 temperatures, being worth 201. per pound when in large sheets, 

 while small sheets only fetch 2d. per pound. The uses are well 

 known, and the consumption is now increasing, but appears to 

 have been greater in early times. The output was given by 

 Dr. McClelland in 1849 as 100,000 raaunds, or about 73,000 

 cwts., and is estimated by Mr. Mervyn Smith at less than 20,000 

 cwts. in 1895. He also states that nearly all the mica used in 

 the arts comes from these mines. 



In the Verhandlungen der k.k. geologischen Reichsanstalt 

 (Wien) for November 30, 1898, Herr A. Bittner contributes an 

 interesting description of some fish remains collected by him 

 NO. 1530, VOL. 59] 



from the Hallstiitter Kalk of Mtihithal bei Piesting. Though 

 the fossils here dealt with consist only of isolated teeth, every 

 such addition to our knowledge is welcome, for, as pointed out 

 by the author, these remains are but rarely met with in the 

 Alpine Trias. While Rh^tic forms have been recorded by 

 Gumbel, and later by Zugmayer, from the Kcissener Schichten, 

 and .Stur discovered a Ceratodiis skull, later described by Teller, 

 at the base of the Lunzer Schichten, no fish remains whatever, 

 as far as the author is aware, have hitherto been chronicled from 

 the Hallstadt limestones. The teeth, illustrated by text figures, 

 are referred to the genera Sargodon and Hyhodus., and are 

 regarded as representing new species. In the same number of 

 the Verhandlungen are papers by Dr. W. Salomon, discussing 

 the age of the Asta granite ; and Herr F. Kerner, who describes 

 several Culm plants irom the Dachschiefer near Johannesbad. 

 Herr F. Schaffer records the occurrence of Miocene strata in 

 the neighbourhood of Siegenfeld, and, on the evidence of fossils 

 obtained from well sinkings, correlates the beds with the Tegel 

 of Baden. 



M. Paul Millet, writing in the Rcviic sclent ifique of 

 January 14, discusses the causes of the disappearance of insect- 

 ivorous birds and the best means of prevention. These causes 

 are twofold in nature, viz. natural causes tending to maintain 

 the balance of nature, and artificial causes due to human agency, 

 to which latter the author chiefly attributes the phenomenon in 

 question. The means of prevention are also of two kinds : 

 methods of a persuasive character, and legislative measures. 

 Among the former may be cited (I) the teaching of ornithophily 

 in schools and colleges ; (2) the posting of printed notices ; (3) 

 introduction of books on birds into public libraries ; (4) re- 

 commendation to teachers in primary schools to insist on the 

 utility of preserving birds and nests. These means are all con- 

 sidered quite inadequate to deal with the evil, and M. Millet 

 considers it desirable to enforce existing laws on the subject (l) 

 by the passing of a regulation forbidding the capture or sale of 

 birds smaller than the lark ; (2) by suppressing the privileges 

 sometimes granted for snaring birds in snowy weather ; (3) by 

 forbidding the sale of instruments for capturing small birds ; (4) 

 by enforcing vigilance on the part of gendarmes and police 

 throughout the year ; (5) by the seizure of small birds at the octroi, 

 in railway stations or in markets ; (6) by taking similar measures 

 against milliners ; (7) by the protection of birds of passage when 

 landing, a measure in which Custom-house officers could assist ; 

 and (8) by killing birds of prey and animals which attack eggs. 

 It is suggested that the French " Ligue Ornithophile " might 

 materially assist in such measures, the need of which is far more 

 urgent in France than in this country. 



To rid beech-trees of that dangerous parasite Cryptococcus fagi, 

 which causes much anxiety to foresters, many methods have 

 been tried. Solutions of soft soap, methylated spirit, and so 

 on, applied to the skin of the tree, are of no avail when the 

 bark has become much decayed. External remedies having in 

 such cases proved useless, Mr. John Shortt, the head forester 

 upon the estate of Sir Matthew White Ridley, Bart., has tried 

 internal ones, and the results are mentioned in the recently- 

 published volume of Transactions of the English Arboricultuial 

 Society. Thirty years ago several trees which were in the 

 last stages of decay were selected, and three holes were bored 

 in the trunk of each, about two feet from the ground, slanting 

 downwards, and converging towards a common centre. Sul- 

 phur, saltpetre, and other substances were placed in the holes 

 — sulphur in one tree, saltpetre in another, and something else 

 in a third — and the holes were then securely plugged. All the 

 trees died except the one that had been treated with sulphur. 

 Since these experiments several other beeches have been treated 

 in the same way, and with equally satisfactory results. The 



