February ig, 1920] 



NATURE 



(>7i 



of Mr. Gaskill's Boards proposes the reservation 

 of a mountain-park, where summer camps and 

 children's playgrounds can flourish along thirty-six 

 miles of practically uninhabited country ; the geo- 

 logical division conducts soil surveys in lands where 

 profitable patches require indication ; it also presides 

 over matters of water-supply, and, curiously enough, 

 over the State Museum, with its permanent and loan 

 educational collections ; and the forestry division fur- 

 nishes admirable illustrations of trees in relation to 

 highways, and of the necessity for maintaining its 

 reserves. It is characteristic, and due to climatic 

 conditions, that the Fire Warden's report should be a 

 considerable feature in this attractive little volume. 

 The use of glauconitic marl as a source of potash 

 is now in the hands of the Spilsbury Engineering Co., 

 of New York, which proposes to produce loo tons a 

 dav of a chemical extract the nature of which is not 

 specified. 



From Freiburg-im-Breisgau, the picturesque Rhine 

 town that so often suffered in return for the savagery 

 of German air-raids, there comes once more the 

 Berichte of the local naturjorschende Gesell- 

 schaft (Bd. xxii., Heft i, 1919), which in happier 

 \ ears maintained our scientific knowledge of the 

 Rhinelands. This part is devoted to a fourfold dis- 

 quisition ("Vier Kapitel") by Prof. W. Deecke on 

 petrographic subjects, the first section being on " Kon- 

 glomeratbildung. " A number of points commonly 

 overlooked in teaching are shrewdly emphasised, such 

 as the necessity for a hollow of erosion or of sinking 

 for the accumulation of a big pebbly mass, and for 

 some form of almost contemporaneous cementation 

 if the conglomerate is ultimately to be preserved. In 

 the section on the " Diagenesis " of sediments Prof. 

 Deecke points out that under varying conditions sub- 

 aqueous sediments are preserved from remote ages 

 as loose material (the sands with bucklered ganoids 

 of Dorpat are an instance), or as consolidated and 

 resisting rocks. The influence of heat and pressure 

 on gels in the interstices between the grains leads to 

 firm cementation, as when iron hydrates pass into 

 magnetite, and garnet develops from calcium car- 

 bonate, quartz, and kaolin by removal of water from 

 the mixture. Next, the mystic words of Suess, 

 "Sal" and "Sima," are critically discussed; the 

 author remarks that there is a "good form" even 

 among geologists (do we not know it in universilv 

 circles?), which maintains the use of such terms 

 beyond their true importance. Dr. Holtedahl's essay 

 on these magmas was referred to in Nature of 

 January 29, p. 574. Lastly, we have an excel- 

 lent review of fossil reef-formation, in which the 

 tendency of similar conditions to produce similar 

 groupings of animal types is excellently impressed 

 upon us. 



English mining engineers may be interested to 

 find that the flotation process is beginning to attract 

 attention in France, as is shown by a lengthy article 

 on the subject in the Revue ginirale des Sciences for 

 January 15, though it must be admitted that the 

 information therein given is far from being either 

 up-to-date or quite trustworthy. It seems curious that 

 NO. 2625, VOL. 104] 



so recent an article should make no mention of 

 Sulman's important contribution to the theory of 

 flotation read before a meeting of the Institution of 

 Mining and Metallurgy in November last, the French 

 author being apparently quite unaware of it. It is 

 strange to read two months after the publication of 

 so exhaustive a treatment of the subject that "the 

 time still appears far distant when a theory capable 

 of explaining the observed phenomena can be estab- 

 lished." Whilst his knowledge of the theory of the 

 process is thus defective, the author of the article 

 in question commits not a few errors in regard to 

 its technology. It is scarcely correct to say that flota- 

 tion is applicable only to ores carrying sulphides, and 

 English readers will be interested to learn that the 

 Murex process is stated to have been devised by an 

 inventor of that name ! 



The Canadian Department of Mines has issued the 

 statistics of the mineral production of Canada for 

 1918 in two reports, one devoted to coal and coke, 

 the other to the metals. The former is, perhaps, the 

 more interesting in view of the immense importance 

 to the whole world of coal output at the present 

 moment. It is pointed out that the term "coal pro- 

 duction " is used in a perfectly definite sense, namely, 

 the total of coal sold plus coal used by the producers, 

 and this must not be lost sight of in comparing 

 Canadian production with that of other countries, 

 e.g. Britain, which latter includes coal lost or un- 

 saleable and coal put into stock. The Canadian pro- 

 duction was 13,373,148 statute tons, as compared with 

 ■2,S4ii749 tons in 1917; there were employed 25,419 

 men, whose average earnings for the year were 

 1294 dollars (or 270Z. at par), equal to 2.46 dollars 

 or los. 2,d. per ton. It should be specially noted that 

 the output per man was 526 tons for the year — a figure 

 that contrasts most favourably with the British 

 figures. The colliery consumption and coal supplied 

 to workmen amounted to 96 per cent, of the pro- 

 duction. Of the more important metals, the copper 

 production was 118,769,434 lb., the highest ever 

 attained; the production of lead was 51,398,002 lb., 

 the highest since 1906; of nickel, 92,507,293 lb., the 

 highest ever recorded; the silver production was 

 2 1.383.979 oz., a falling-off of 37 per cent, as compared 

 with 1917; and the gold production was 699,681 oz., 

 o'' 5'3 PC cent, below that of 1917. 



M.nuRiTius meteorological, magnetical, and seismo- 

 logical records are issued in the monthly and annual 

 reports of the Royal Alfred Observatory, under the 

 directorship of Mr. A. Walter. The annual report for 

 1918 and the monthly reports to August, 1919, have 

 been received. Continuous photographic registration 

 is made of atmospheric pressure, temperature of the 

 air and evaporation, and automatic registration of 

 direction and velocity of wind, of rainfall, and of 

 bright sunshine. The photographic registrations have 

 been checked at regular intervals by eye observations, 

 and daily observations are made of terrestrial radia- 

 tion and of thermometers ranging from 3 in. to 1 18 in. 

 below the surface soil. Monthly, quarterly, and yearlv 

 departures from the normal are given for the several 

 elements. In iqi8 the temperature of the air was 



