September 27, 1906] 



NA TURE 



547 



most of the material was also analysed. The principal 

 conclusions derived from their experiments by the authors 

 arc : — (i) that in many sediments of all ages extremely 

 fine particles, especially " quartz-dust," play an important 

 part ; (2) that most of the quartz-dust has been produced 

 by the collision and abrasion of quartz grains while 

 suspended in water, and that the perfect rounding of some 

 quartz grains, usually assumed to be due to wind action, 

 may be largely due to this subaqueous abrasion ; (3) that 

 carbonate of lime may often be present in suspension in 

 considerable amount in natural waters ; and (4) that the 

 microscopic suspended matter is probably an important item 

 in the total solid content of the waters of the open sea. 

 In the same volume Messrs. T. Mellard Reade and Joseph 

 Wright have a short paper on the Pleistocene clays and 

 sands of the Isle of Man, which is mainly occupied by lists 

 of the Foraminifera found in the drift. 



On May 15 the city of Nuremberg opened a national 

 exhibition in commemoration of the centenary of its sub- 

 jection to the Bavarian Crown. The exhibition, which 

 will remain open until October, has proved eminently 

 successful. It contains a good display of Bavarian manu- 

 factures, and is of special interest from the admirable 

 manner in which the mineral resources of the kingdom are 

 shown. The mineral deposits represented include the iron 

 ores of the Fichtelgebirge, coal from the Palatinate, iron 

 pyrites and galena from Bodenmais, salt from Berchtes- 

 gaden, copper ore from Imsbach, and graphite from 

 Passau. 



Thb Engineering Standards Committee has issued its 

 standard specifications for material used in the construc- 

 tion of railway rolling stock. This report, No. 24 (London : 

 Crosby Lockwood and Son, price los. 6d. net), covers sixty- 

 two folio pages, and is undoubtedly one of the most com- 

 plete and valuable of the publications of the committee. 

 It contains specifications for locomotive crank axles and 

 straight axles, carriage and waggon axles, tires, springs, 

 steel forgings, steel blooms, steel castings, copper plates, 

 rods and tubes, brass tubes, and steel for plates, angles, 

 and rivets. In each case specifications are given, with and 

 without chemical analyses. The committee has also issued 

 a standard specification for steel conduits for electrical 

 wiring (report No. 31, price is. 6d. net), and a report 

 (No. 28, price 2S. 6d. net) on British standard nuts, bolt- 

 heads, and spanners. 



In the Journal of the Franklin Institute (vol. clxii., 

 No. 2) Mr. Clifford Richardson concludes his elaborate 

 memoir on the petroleums of North America, in which he 

 compares the character of those of the older and newer 

 fields. Those of the earlier days of the industry, from the 

 Appalachian field, were paraffin oils, free from sulphur, 

 specially valuable for the production of illuminants. The 

 petroleums of north-western Ohio and Canada, next de- 

 veloped, being sulphur oils, were far less valuable. The 

 California oil is composed of such a series of hydrocarbons, 

 of a non-parafiin nature, that its value is comparatively 

 small. The oils from the more recently developed fields of 

 Kansas and Texas are of variable character. Those from 

 the Gulf Coastal Plain of Texas and Louisiana are so 

 strongly asphaltic as to be of value only for the produc- 

 tion of lubricants, for use as fuel, and as gas-oil. 



" The Effects of Civilisation upon Climate " is the title 

 of an interesting article by Mr. S. L. Bastin in the 

 September number of the Monthly Review. As the author 

 points out, the subject is by no means new, and is a 

 matter upon which many authorities find themselves at 

 NO. 1926. VOL. 74] 



variance. As one instance of how a locality may be in- 

 fluenced by some artificial feature the smoke of London is 

 referred to, the effect of which is visible in the hilly 

 villages of Oxfordshire when the wind is in the right 

 quarter. Agam, it is well known that in large cities the 

 average annual temperature is higher than in the surround- 

 ing country, while the reduction of the amount of marsh 

 land, e.g. in the Fen district, has probably had a decided 

 effect upon the temperature. But these are local instances ; 

 whether the climate has changed generally is another 

 matter. Hann and others have shown that there are 

 evidences of changes of small amount sometimes in one 

 direction and sometimes in another, e.g. the fluctuations 

 in the size of European glaciers. The author assumes that 

 British winters are later in coming than they used to be, 

 and quotes that of 1894-5, " when the rigours of the season 

 were scarcely felt until February, and were extended well 

 into March." A discussion of this frost in the Journal of 

 the Royal Meteorological Society shows that the cold 

 period commenced on December 30 and ended on March 5, 

 with a break of a week's mild weather from January 14-21. 

 On January 8 the temperature fell to —3" at Braemar, 

 and was below 10° over the central part of north Scotland : 

 after February 20 no readings below 10° were recorded. 

 As to the influence of forests, we can have no better 

 authority than Hann ; they do reduce the mean air 

 temperature, especially during the warmer part of the year, 

 but whether they increase the amount of rainfall, and, if 

 so, to what extent, cannot yet be definitely answered. Wc 

 hope with Mr. Bastin that special attention will be given 

 to this important subject in the future, and that, with 

 better data at command, valuable conclusions may be 

 obtained. 



In the American Journal of Science (vol. xxii., p. 176) 

 Mr. S. E. Moody gives an account of experiments on the 

 hydrolysis of iron, chromium, tin, cobalt, and nickel salts 

 by solutions containing alkali iodide and iodate. In this 

 reaction an equivalent quantity of iodine is set free, the 

 estimation of which may be used for the quantitative deter- 

 mination of any of the above metals. In the case of zinc 

 salts, the hydrolytic decomposition is only partial, and a 

 basic salt is precipitated instead of the hydroxide. 



In the Annalen der Physik (vol. xx., p. 677) Dr. E. 

 Marx gives an account of an experimental investigation 

 relative to the velocity of Rbntgen rays. It is estimated 

 that the method and apparatus employed permit the velocity 

 to be determined with an accuracy represented by a prob- 

 able error of i per cent. Within this limit the velocity 

 of propagation of Rontgen radiation is equal to that of 

 light. This result furnishes strong evidence in favour of 

 the view that Rbntgen radiation consists in electromagnetic 

 pulse transmission through the ether. 



The velocity of the a particle emitted by radium C at 

 various points of its path has been recently measured by 

 Trof. Rutherford (Phil. Mag., xii., 134). After traversing 

 70 centimetres of air the o particle is no longer capable of 

 exerting any sensible photographic action, although its 

 velocity is still approximately four-tenths of the velocity 

 with which it is emitted from the active source. The 

 much more rapid decrease of the photographic effect of the 

 particle towards the end of its path as compared with the 

 alteration in its kinetic energy necessitates the assumption 

 of a certain critical velocity below which the particle is 

 unable to produce the characteristic effects, or of a very 

 rapid decrease in the velocity when this reaches a certain 

 value. 



