December 15, 1910] 



NATURE 



2 1 



In an abstract from the American Breeders' Magazine 

 (vol. i., No. 2) Dr. G. H. Shull adduces further evidence 

 in favour of a so-called pure-line method in corn breed- 

 ing that consists in raising self-fertilised generations with 

 the object of developing pure homozygous strains or 

 biotypes, and then cross-breeding from such pure strains 

 year by year. 



A NOTE on works of improvement in the forests of the 

 Federated Malay States, contributed by Mr. A. M. Burn- 

 Murdoch, appears in the Indian Forester (October). The 

 author distinguishes gutta-percha forests, where Palaqitium 

 giitta and P. oblongifolium are the important species, and 

 mixed timber forests. Under natural conditions the 

 Palaquium forests contain a great number of tall, slender 

 trees in the pole stage arising from an undergrowth of 

 palms, chiefly Eugeissona tristis, and shrubs ; there are 

 also a few giant trees. When the young trees are cleared 

 of the undergrowth some are unable to support their own 

 superstructure and require lopping, from which, however, 

 they quickly recover. 



A PALM disease receiving the name of " koleroga " is 

 described at length by Dr. L. C. Coleman in Bulletin 

 No. 2, issued by the Department of .Agriculture in the 

 Mysore State. The disease, confined to the Areca palm, 

 has been prevalent in two separate areas on the west coast 

 of India. For the most part the fruits are attacked, but 

 occasionally the fungus finds its way to the growing apex. 

 Spraying with Bordeaux mixture has proved efficacious. 

 From a study of the sporangiophores, zoospores, and both 

 kinds of sexual organs, and from infections made with 

 the spores, the author concludes that the fungus is very 

 closely allied to the well-known Phytophthora omnivora, 

 from which he separates it as a special variety. 



The prominent item in the September number (vol. v.. 

 No. 4) of the botanical section of the Philippine Journal 

 of Science is the first part of a description, by Mr. E. D. 

 Merrill and Mr. M. L. Merritt, of the flora of Mt. Pulog, 

 the highest, but until recently little known, peak in the 

 island of Luzon. Four zones of vegetation are dis- 

 tinguishable, of which the most important is an open 

 forest belt in which Pinus insignis is the characteristic 

 tree; this gives place at an altitude of 7000 feet to a 

 denser forest of irregular trees covered with mosses and 

 lichens, where epiphytic ferns and orchids are abundant, 

 while the summit is open meadow. In the flora the 

 families Polypodiacea-, Compositae, and Gramineae are best 

 represented. There is a predominance of continental 

 Asiatic as opposed to .Malayan types, together with a 

 definite, although small, admixture of Australian elements. ■ 



Mr. Bernard Smith has written on the Upper Keuper 

 sandstones of east Nottinghamshire in the Geological 

 Magazine for 1910 (p. 302). His study of the characters 

 of these rocks bears out the view, shared by Mr. Cress- 

 well in the paper above referred to, that they were 

 accumulated in distinctly shallow water. " Large tracts 

 with isolated pools were laid bare from time to time." 

 The sandstones among the marls are the deposits of wet 

 seasons, and show characteristic signs of flood and current 

 action. Mr. Smith suggests that the grey or green beds 

 in the Keuper are due to the check on oxidation caused 

 by organic remains and humic and organic acids swept 

 down from the land-surface. 



From the report of the chief of the U.S. Weather 

 Bureau for the fiscal year 1908-9 we note that observa- 

 tions of the lower strata of air by kites and captive 

 balloons are made daily except on Sundays; efforts are 

 NO. 2146, VOL. 85] 



being made to secure materials for kites that wiil not 

 absorb moisture. Measurements of the intensity of solar 

 radiation and the polarisation of sky light were made 

 whenever conditions were favourable ; both appear to have 

 had a higher value than during the previous year. Iso- 

 baric charts based on telegraphic reports from selected 

 stations throughout the northern hemisphere have been 

 prepared daily, and successful forecasts for about a week 

 in advance have been issued at intervals ; Prof. Moore 

 remarks that the application of world-wide observations 

 and upper-air researches to the art of weather forecasting, 

 both for short and k)ng periods, is yearly becoming more 

 apparent. Reports of marine observations by wireless 

 telegraphy have been discontinued on the Atlantic, but the 

 work has been taken up, to some extent, on the Pacific 

 coast. In the climatological summaries we note that the 

 total precipitation is determined from amounts recorded 

 daily, from midnight to midnight. 



Dr. L. Birkenmajer, of the Cracow Uriversity, the 

 author of an elaborate biography of Copernicus, has been 

 fortunate to find (in the " Riks-Arkivet," Stockholm, and 

 in the library of Upsala University) several entirely un- 

 known autographs of Nicolaus Copernicus. The most 

 interesting is a letter written by the great astronomer, on 

 behalf of the Bishop and the Cathedral Chapter of Erm- 

 land, on July 22, 1516, to Sigismond I., King of Poland. 

 This message conveys to the King embittered complaints 

 against the Teutonic Order " the Knights of the Cross," 

 described as " praedones, latrones et homines scelerati " 

 in the text of the document, which is entirely in 

 Copernicus 's own handwriting. For other interesting 

 details we must refer to the memoir published by Dr. 

 Birkenmajer, in collaboration with the distinguished 

 Upsala scholar Dr. Isak Collijn, in the Bulletin Inter- 

 national of the Academy of Sciences of Cracow, June, 

 1909. 



The paper read by Sir Robert Hadfield and Prof. B. 

 Hopkinson before the Institution of Electrical Engineers 

 on Thursday last marks an important advance in our 

 knowledge of the magnetic properties of iron and its alloys. 

 By working in the intense fields obtained between the 

 poles of a large electromagnet they have succeeded in 

 showing that iron and its alloys with carbon, silicon, 

 aluminium, nickel, or manganese have definite saturation 

 intensities of magnetisation which are reached, in general, 

 in fields of less than 5000 units. For pure iron the 

 saturation intensity is 1675 units, and for iron carbide 

 about two-thirds of this. Each alloy behaves as a mixture 

 of one or more magnetic substances with materials having 

 permeabilities not differing much from unity. In 

 annealed carbon steels the saturation intensities are 6 per 

 cent, less than for pure iron for each per cent, of carbon 

 present. The tests of alloys of iron with nickel and 

 manganese have not led to any simple relation between 

 their magnetic properties and their composition. 



Since Coulomb stated the laws of friction of soHds on 

 each other more than a century ago, little work has been 

 done on the subject except from the technical point of 

 view, which does not attach much importance to the 

 absolute cleanliness of the surfaces in contact. The 

 Verhandlungen der Deutschen Physikalischen Gesellschaft 

 for October 30 contains a short account, communicated by 

 Prof. W. Kaufmann to the Versammlung Deutscher Natur- 

 forscher, of some careful experiments on the subject made 

 by his pupil Miss C. Jakob. The glass or brass surfaces 

 used were chemically clean, and were used in a glass 



