398 



NA TURE 



[February 22, 1906 



A Bulletin on " The Mineral Constituents of the Soil 

 Solution," by Messrs. F. K. Cameron and J. M. Bell, has 

 been received from the U.S. Department of Agriculture 

 (Division of Soils, Bulletin 30, 1905, pp. 70). Tli i- latest 

 publication of the division over which Mr. Whitney presides 

 df-als with the problem that has been the subject of so 

 much of the recent work on soils done by the United 

 States Department of Agriculture — the composition of the 

 solution formed by the water in the soil. It is generally 

 recognised now that plants feed on this solution and are 

 incapable of attacking the solid constituents of the soil, 

 so that the composition and mode of origin of this solu- 

 tion must furnish the interpretation of many of the difficul- 

 ties regarding the relationship of crops to soils. The 

 Bulletin is more of a general discussion and a bibliography 

 than a record of new investigations ; it sets out a brief 

 account of most of the work that has been done on such 

 matters as the solubility of the minerals composing the 

 soil, the hydrolysis and similar changes then taking place, 

 adsorption and absorption by finely powdered materials, 

 flocculation, surface reactions, and such other phenomena 

 in the borderland of chemistry and physics as must play 

 a leading part in the reactions going on in the soil. The 

 main thesis of the Bulletin is that the soil materials hydro- 

 lyse and form a solution in equilibrium with the portion 

 which remains solid ; this position of equilibrium will be 

 continually restored or maintained whenever it is tempor- 

 arily disturbed, as by the addition of manures or the with- 

 drawal of substances by growing plants. We fail to 

 perceive, however, that all the parade of authorities lend 

 any support to the extraordinary doctrine which the 

 American official soil chemists seem to have adopted as an 

 article of faith— that all soils, whatever their origin or 

 treatment, yield the same soil solution, and therefore 

 possess the same nutritive power. Putting aside this " con- 

 clusion," which is brought in at the end, though nothing 

 particular seems to have led up to it, all workers in this 

 field will be glad to possess the Bulletin as a guide to thi 

 scattered literature on a difficult subject. 



We have received from Mr. G. Henriksen, of 

 Christiania, a translation of his pamphlet, written in 

 Norwegian, on the iron-ore deposits of Sydvarangei 

 Finmarken, Norway. Iron ore occurs in large quantities 

 in gabbro. It consists exclusivelj ol magnetite. The 

 deposits are considered by the author to have been formed 

 bj the action of pressure on eruptive rocks. 



It is reported in the Engineering and Mining Journal 

 (vol. Ixxxi., No. 4) that great development has taken place 

 in gem production in Brazil. Exploration in Minas Geraes 

 has led to discoveries ol tourmaline which have furnished 

 red, blue, and green gems, and of beryl- which have 

 furnished magnificent blue and green stones. A large 

 quantity of Brazilian amethyst has been obtained from the 

 great geode, the bulk of which was shown at the Diissel- 

 dorl Exhibition in 1902. 



1 '■ to the present time the manufacture ol chilled 

 rolls has remained purely empirical ; and a paper by Mr. 

 E. de Loisy in the Bulletin de la Sociiti d' Encouragement 



(vol. cvii., No. to), describing his researches made to 

 ascertain the scientific rules thai should guide the iron- 

 founder, is therefore well worthy of careful attention. 

 For chilled rolls for rolling steel sheets or wire rods the 

 composition sought should be as follows : — carbon, 29 

 to 3; silicon, 07 to 0-9 ; manganese, 05 to to; and 

 phosphorus, 035 to 045. The addition of steel scrap 

 to pig-iron is recommended, but the proportion should not 



NO. 1895, v OL. 7$) 



be much above 15 per cent. The author gives a large 

 number of analyses of .hilled rolls that have lasted well 

 in the rolling-mill. 



An interesting note on prospecting in the Transbaikalian 

 goldfields has been communicated by Mr. R. Farina to the 

 Institution of Mining and Metallurgy (Bulletin No. 17). 



The district has long I n famous for its gold placers. 



Platinum and cinnabar are also met with. The gold veins 

 vary greatly in character. Those rich in gold are very 

 porous, friable, and highly oxidised. The other veins are 

 of the hard white quartz type. The best time for pro- 

 specting is March and April, when the snows have almost 

 gone. The rocks of the country are chiefly quartz 

 porphyry, granites, andesites, diorites, and gneiss. In a 

 note, in the same Bulletin, on tin in Tringganu, on the 

 easl coast oi the Malay Peninsula, Mr. C. G. P 

 Lock records the occurrence, in the alluvial tin fields, ol 

 monazite and xenotime in pot-holes in the granite beds 

 of tlie streams. 



The J.nnual of the Society 0] Chemical Industry (vol. 

 xxv., No. 2) contains an interesting paper by Mr. A. II. 

 Hiorns on the effect of certain elements on the structure 

 of cast iron. He gives a summary of previous researches 

 on the subject, and describes some experiments made by 

 himsell with pure cast iron to which various proportions 

 ol silicon, manganese, phosphorus, and sulphur were added. 

 He gives illustrations showing the appearance of polished 

 and etched surfaces examined under the microscope. In the 

 discussion, Mr. W. Rosenhain referred to the process of 

 heat tinting in connection with the detection of the presence 

 of phosphorus, and pointed out two very serious difficulties 

 that had to be overcome before satisfactory results could 

 be obtained. These were the difficulty of obtaining the 

 surfaces in a perfectly clean state, and the fact that the 

 actual surface very often did not represent the real struc- 

 ture of the metal, because the very act of polishing tended 

 to spread the softer constituents over the harder, and in 

 all cases produced a definite layer of altered material. 



We have received from Mr. G. T. Beilby a reprint, in 

 pamphlet form, of his presidential address to the Glasgow 

 University Engineering Society, delivered on January it. 

 In it he discusses, with a thorough mastery of his sub- 

 ject and with conspicuous literary skill, some of the wider 

 aspects of modern power production for industrial pur- 

 poses, more particularly with reference to the fuel re- 

 sources of the country. He shows that the annual coal 

 consumption of the United Kingdom is 167 million tons,. 

 ihe various channels of consumption being as follows, in 

 millions of tons: — railways, 1 i ; coasting steamers, 2; 

 factories, 53; mines, iN ; iron and steel industries, 28; 

 other metals and minerals, 1 ; brick-works, potteries, glass- 

 works, and chemical works, 5; gas works, 15; and 

 domestic, ,;-■. Taking the consumption of coal for power 

 purposes at mines and factories as 52 million tons, a 

 saving of some 42 million tons could be realised with time 

 and enterprise. There are in Great Britain steam engines 

 and boilers with a yearly output of at least 5 million 

 horse-power. The coal consumed by these i, not less than 

 5 lb. per indicated horse-power hour, or on the whole 

 40 million tons. By the use of gas engines and steam 

 turbines the coal consumption might be reduced to i£ lb. 

 per indicated horse-power hour, or on the whole to 12 

 million tons. The saving in coal, therefore, is equal to 

 28 million tons, valued at 9,800,000/. The cost of making 

 the change need not exceed 50,000,000/., or, if the power 

 is to be delivered as electrii ity, 6o,ooo,ooo2. The saving irt 



