Dec. 14, 1888.] 



SCIENTIFIC NEWS. 



599 



Cutch and Gambier. — H. Trimble, in the American 

 J ' ournal of Pharmacy, controverts the common notion 

 that cutch and gambier are identical in composition. 



Blindness in Russia. — Of the cases ot blindness in 

 Russia, which are said to be more abundant among the 

 Finnish-Mongolian races than among those of Aryan or 

 Semitic origin, one-eighth are due to smallpox, and one- 

 half only to direct disease of the eye. 



Rats and Electric Lighting. — M. Helbig, of Rome, 

 writes to La Nature that the electric lighting in that 

 city had been interrupted in a very curious manner. A 

 rat, in passing over a commutator, formed a short circuit, 

 thereon the cut-outs immediately melted. 



A New Microscopical Society. — A microscopical 

 society is in the course of organisation at Edinburgh, 

 and it seems likely to begin operations under favourable 

 auspices. Curiously enough, a resolution was carried 

 declaring ladies ineligible for membership. 



Prevalence of Rickets in Sheffield. — Dr. C. V. 

 Gwynne says that few towns in the empire can com- 

 pete with Sheffield in the production of rickets, and to 

 this it is in no small extent due that the inhabitants 

 possess the smallest physical type of any large town in 

 the kingdom. 



The Proposed Zoological Garden at Washington. 

 — It is painful to learn from the American Naturalist that 

 the proposed Government Zoological Garden at Wash- 

 ington has been rejected on the plea of economy. This 

 in the case of a Government which is at a loss how to 

 spend its surplus. 



Rain in Egypt in 1888. — In the memory 01 man, 

 says La Nature, no rain has fallen in Egypt in the month 

 of June. This year on June 3rd the following quan ti- 

 tles have fallen and have been duly measured : at 

 Alexandria 0*2 millimetre, at Cairo 1*15, at Port Said 

 5 -6, and at Suez ro millimetre. 



The Arrest of Civilisation in China. — Miss Adele 

 M. Fielde {Popular Science Monthly) ascribes the arrest 

 of Chinese civilisation in part to the peculiar marriage 

 customs of that country, in virtue of which " sexual 

 selection " is rendered inoperative, as the contracting 

 parties have before espousal no opportunity to judge of 

 the strength, beauty, and intelligence of their consorts. 



The Survey of the Nicobar Islands. — Colonel 

 Strahan, who has just surveyed this group, reports their 

 total superficies as 618 square miles. The highest 

 summit is 2,105 f eet above the sea level. The scenery 

 is said to be of indescribable beauty. Some of the 

 rivers are navigable for boats to a considerable distance. 

 The natives are apparently allied to the Malays ; they 

 are of a reddish-brown colour, finely developed, and 

 have a remarkable talent for learning languages. 



Colour of Lightning.— In a storm which occurred at 

 Altona in August last, some interesting observations 

 were made on the colour of lightning. Of the ten first 

 flashes three were red, one greenish-red (a peculiar 



colour), one reddish-blue, one blue, one greenish-blue, 

 and three doubtful. Ot the ten following there were 

 four red, of the ten next six red, and of the following ten 

 eight red. Of the seven last, three were completely red. 

 In the second part of the storm the number of the red 

 flashes, according to the Meteorolog Zeitschrift, was still 

 greater. 



The Purity of Gold. — Dr. Cohen (Nattirwissensch 

 Verein fur Neuvorpommern und Riigen) discusses the 

 arguments on behalf of the chemical theory of the de- 

 position of gold in placers compared with those in favour 

 of its mechanical origin. He shows that some of those 

 urged in favour of the chemical theory are of doubtful 

 existence. Thus it has been stated that placer gold 

 always contains less silver than vein gold from the 

 same region. Analyses ot specimens from Buttons 

 Creek, in the South African gold-fields, show that such is 

 not always the case. Thus a sample of vein gold yielded 

 94^48 per cent, of gold, and 5-16 of silver, whilst two 

 samples of placer gold showed respectively 91 '38 and 

 95 '02 of gold, and 6^49 and 4-60 of silver. He thinks 

 that placer gold is mostly derived from the breaking down 

 ot gold veins, but that there is occasionally, in addition, a 

 deposition of the metal from its solutions. 



The Conditions of the Earth's Interior. — The 

 following considerations put forward in the American 

 Naturalist, by Ira Sayles, claim serious attention. It 

 has been held by some authors, that no crust can form 

 over a molten sphere, for, say they, when the surface 

 cools it is heavier than the molten mass within, and must 

 necessarily sink; so that the centre would become solid first. 

 (Solid tin floats upon melted tin ! ) Second, ejected lavas 

 always cool on the surface first, while yet the deeper 

 portions are molten, and continue to flow long after a solid 

 crust has been formed. Thus does direct observation 

 show the falsity of their hypothesis. Third, these authors 

 neglect the fact that the lighter materials lie like a thick 

 blanket around the outside 01 the sphere, and even 

 though they were to become frozen, they could never sink 

 into the molten heavier matter. Cold iron will not sink 

 in molten gold ; cold silicon cannot sink in molten 

 iron. Fourth, these lighter materials are highly non- 

 conductive to heat, and hence husband the internal heat. 



Department of Science and Art. — Mr. W. Crookes, 

 F.R.S., has presented to the Department of Science and 

 Art a collection of sixty-eight radiometers and similar 

 instruments for permanent exhibition in the science 

 galleries of the South Kensington Museum. They illus- 

 strate the steps by which Mr. Crookes was led to the 

 construction of the radiometer, and to the production of 

 motion and of phosphorescence by streams of electrified 

 molecules in high vacua. Many of the instruments are 

 of the greatest historical interest. Among them is in- 

 cluded the first radiometer, with many others which are 

 described in Mr. Crookes's papers in the Philosophical 

 Transactions of the Royal Society. Others are of con- 

 siderable value, as they contain collections of diamonds, 

 rubies, etc., for the exhibition of the phenomena of 

 phosphorescence. Nearly all are in working order, and 

 will be ot great use in illustrating lectures to students 

 in the Normal School of Science at South Kensington. 

 The collection will be on view in the galleries of the 

 Museum in Queen's Gate as soon as the necessary stands 

 and sittings are completed, 



