August 2, 1906J 



NA TURE 



337 



Tin; Department of Agriculture in India has commenced 

 the issue of a cliemical series of memoirs. Part 1. con- 

 t.-iins an article by Dr. J. W. Leatiier, agricultural chemist 

 to the Government of India, on the composition of Indian 

 r.iin and dew. The author points out that the amount of 

 ammonia and nitric or nitrous acid found in the annual 

 rainfall by observers in different parts of the world has 

 varied within wide limits. The observations at Rolhamsted 

 during fifteen years, 1889-1903, show mean quantities of 

 2-78 lb. of " ammonia " nitrogen and i-ig lb. of " nitric " 

 nitrogen per acre per annum, the total being 3.97 lb. ; 

 but there has been a tendency among observers in the 

 East to attribute to tropical rainfall much greater amounts. 

 A record of these compounds was kept recently for twelve 

 months at Dehra Dun and Cawnpore, both stations being 

 nearly within the tropics, and is of interest as additional 

 evidence upon the subject. The results obtained were, 

 approximately, in lb. per acre : — Dehra Dun, ammonia 

 204, nitrate and nitrite 1-37, total 3-41 ; Cawnpore, 2-48 

 and 077 respectively, total 3-25, the amount of ammonia 

 being less at both stations than at Rothamsted ; of nitric 

 acid, the Dehra Dun rain contained somewhat more, the 

 Cawnpore rain a good deal less, than at the English 

 station. Information regarding the quantity and composi- 

 tion of dew is but limited. Observations were made at 

 Cawnpore between September, 1904, and March, 1905 ; the 

 amount of dew was only 01 7 inch, and contained appro.\i- 

 matply 0055 lb. of "ammonia" nitrogen and 0056 lb. of 

 " nitric" nitrogen per acre. Dr. Leather thinks it probable 

 that the method adopted at Cawnpore for registering the 

 .imount of dew gave a low result. 



The value of statistical researches in the subject of 

 heredity and variation is well illustrated by a paper lately 

 published in the Proceedings of the American Academy 

 of Arts and Sciences, under the joint names of W. E. 

 Castle, F. W. Carpenter, \. H. Clark, S. O. Mast, and 

 W. M. Barrows, on the effects of inbreeding, cross-breed- 

 ing and selection upon the fertility and variability of 

 Drosophila, a genus of Diptera which feeds in the larval 

 stage on over-ripe fruit. The experiments were conducted 

 with great care, and their results recorded with minute- 

 ness, the outcome being a valuable set of conclusions on 

 various moot points connected with the subject. The 

 authors consider that their experiments prove that, 

 although long-continued inbreeding (extending in one case 

 to fourteen generations) may possibly cause a decline in 

 fertility, this effect may be more than counterbalanced by 

 selection of the most productive among closely inbred 

 pairs. No falling-off was observed in either strength, size, 

 or variability in the inbred generations. Different degrees 

 of fertility are characteristic of different stocks ; inherit- 

 ance of such differences does actually take place, and gives 

 material for selection. Indications were found of a cyclical 

 change in fertility. This appeared to be due to external 

 conditions, e.g. temperature. The quality of low pro- 

 ductiveness was found to conform imperfectly with Mendel's 

 law, but the alternative character of high and low fertility 

 is not sharply defined. Sexual maturity was shown to be 

 reached at some time between twenty-four and thirty-nine 

 hours after emergence from the pupa, and a single male 

 was proved to be capable of fertilising at least four 

 females. 



Dr. Shadworth H. Hodgson's paper on the inter- 

 relation of the academical sciences, read to the British 

 Academy on March 14, has been published by Mr. Henry 

 Frowde. Dr. Hodgson asks what is the common ulterior 

 NO. 191 8, VOL. 74] 



end of the four sections of the British Academy, dealing 

 as they do with the different sciences of history, philology, 

 philosophy, and law. These four branches of inquiry, 

 he discovers, have to do with man, and his conscious 

 activities in every direction, and the relations of men with 

 men and with other conscious beings; and the whole group 

 has as its differentia from the positive physical sciences 

 the fact that it takes consciousness as the point of view. 

 So the ulterior aim of all the sections is the harmonising 

 and organising into a system of the knowledge obtained 

 in each section and subsection of those conscious activities 

 which are its special province, with the further purpose 

 of harmonising those conscious activities themselves into 

 a concerted life of mankind on earth. The lecturer further 

 claims that internal organisation of the academical sciences 

 can only be effected by connecting the sciences of history, 

 philology, and law with philosophy, " which alone 

 possesses in its metaphysical department a secure found- 

 ation for any science whatever, being itself founded, alone 

 among all, upon the analysis of consciousness, or experi- 

 ence, without initial assumptions of any kind." 



The " Year-book of Agriculture " for the State of 

 Victoria for the year 1905, recently issued under the super- 

 vision of its new director of agriculture. Dr. Cherry, con- 

 tains a series of valuable articles on economic biology. It 

 supplies an interesting case of the rapid spread of a 

 European plant in Australia, which is of value from the 

 exact information available as to its rate of movement. 

 Some seeds of a species of St. John's wort (Hypericum 

 perforatum) were planted at Bright twenty-five years ago 

 by a lady who wanted the plant for medicinal purposes. 

 From her garden it spread to the Bright racecourse, where 

 it grew so luxuriantly that it gained the popular name of 

 the " racecourse weed." Thence it has been carried by 

 cattle, as shown by a map of the present distribution of 

 the plant in Victoria, along all the main stock routes from 

 Bright. Among other directions it has crossed the main 

 water-shed of Victoria into Gippsland, and now occupies 

 more than 10,000 acres of good land. Methods proposed 

 for its eradication are engaging the attention of the Agri- 

 cultural Department of Victoria, which has tried an 

 extensive series of experiments. Treatment of the ground 

 with pyrites, at the cost of more than 5;. an acre, has 

 been the most successful. The cost of some of the methods 

 tested is prohibitive, ranging up to 47J. an acre. Amongst 

 other valuable articles in the volume are those on the soils 

 of Victoria, by Dr. Cherry ; on farm irrigation from small 

 dams, by Mr. A. S. Kenyon ; and on various branches of 

 dairy farming 



The report of the committee on ancient earthworks and 

 fortified enclosures, presented to the seventeenth con- 

 gress of archajological societies held at Burlington 

 House on July 4, is now available. The committee 

 regrets that the archaeological societies have not yet 

 been able to undertake the systematic scheduling of the 

 ancient earthworks and defensive enclosures in their re- 

 spective districts. The report contains a list of the addi- 

 tions to the literature of the subject of the committee'."; 

 inquiries, a list of recent cases of the destruction or mutila- 

 tion of defensive outworks, tumuli, and barrows, and some 

 account of the excavations during the year. 



A valuable memoir of the Geological Survey on " Soils 

 and Subsoils from a Sanitary Point of View, with especial 

 Reference to London and its Neighbourhood," was issued 

 nine years ago. The second edition of this memoir has 

 just been published by the Board of Agriculture and 



