526 



NA TURE 



[October 14, 1922 



Research Items. 



The Roman Balance in South America. — Mr. 

 Erland Nordenskiold has reprinted from the journal 

 of the Societe des Americanistes de Paris (N.S. vol. 

 xiii., 1921) an article sub-entitled " Emploi de la 

 balance romaine en Amerique du Sud avant la 

 conquete." He produces evidence, with a full 

 bibliography of authorities, to show that this invention 

 was not confined to the Old World, but was found in 

 the New World before the discovery of America. 



Anthropology in the Chiltern Hills. — In the 

 Journal of the Royal Anthropological Institute (vol. 

 lii. Part i), Mr. W. Bradbrooks and Prof. F. G. Parsons 

 publish an elaborate memoir, with a long series of 

 measurements of skull form, on the population of 

 the Chiltern Hills, in which they arrive at the following 

 conclusions : in this comparatively isolated area 

 about half the working-class male people can trace 

 their ancestry back to three generations in some part 

 of the area ; the hair colour is rather darker than 

 Beddoe found in the Eastern and East Midland 

 Counties, and the proportion is higher than in any 

 other part of Great Britain, except the South-western 

 Counties and Wales ; the eye colour is identical with 

 that of London and the East Midlands ; the average 

 cephalic index, 777, is practically that of the modern 

 working man in London, and the average height, 

 5 ft. 7 in., is that of the black-haired individuals. 

 Thus, the present-day inhabitants of the North 

 Chiltern area, who are not recent immigrants, are 

 distinctly darker haired than those surrounding them, 

 and this darkness appears to be due to the survival 

 of a great proportion of Neolithic or Mediterranean 

 blood in the district. 



Distribution of Future White Settlement. — 

 The problem of the potentiality of the world for white 

 settlement is attacked quantitatively by Dr. Griffith 

 Tavlor in. the Geographical Review for July. The 

 world is divided into economic regions which coincide 

 111 1 1 1 ■ ■ main with Herbertson's natural regions. The 

 areas of these regions are determined by planimeter 

 measurements. The factors influencing human settle- 

 ment are grouped under four headings which comprise 

 the dominant controls — temperature, rainfall, 1< icatii in, 

 and coal reserves. Fisheries have local rather than 

 general importance and are ignored. From the values 

 of each of these four controls a quadrilateral graph, 

 the econograph, is constructed for each region, and the 

 area of the graph is found to represent approximately 

 the habitability of the region concerned. The econo- 

 graph is a rectangular figure formed on four axes 

 which represent, respectively, the average annual 

 temperature, the average annual rainfall, the average 

 elevation, and the estimated total coal reserve of the 

 region. In what Dr. Taylor believes to be the ideal 

 region these values would be 55° F., 50. in., sea-level, 

 and 200 x io 4 tons per square mile. The comparative 

 value of these controls was apparently reached by 

 assuming various values and testing them against the 

 actual population map of Europe. By this means 

 Dr. Taylor decided to give the temperature control 

 double the weight of the rainfall and allow the coal 

 factor, if large, to have equal weight with optimum 

 temperature and rainfall combined. The ideal econo- 

 graph represents 1000 units. All the seventy-four 

 regions of the world have values below this ideal. 

 The last step was to plot on a map of the world the 

 numbers representing the areas and draw lines of 

 habitability, called isoiketes. This map is of great 

 interest as a partially successful attempt to forecast 

 the future growth of white settlement. 



Mosquito Investigations. — Since the statement 

 was made by Messrs. Carter and Blacklock that 

 Anopheles plumbeus is a potential carrier of malaria 

 in this country, it having been experimentally in- 

 fected by them, considerable interest has been taken 

 in the habits and distribution of the species in Britain. 

 Following studies made by these authors in the Liver- 

 pool district and in the Isle of Man, an inquiry was 

 instituted by the mosquito investigation committee 

 of the South-Eastern Union of Scientific Societies, 

 acting on behalf of the Ministry of Health. The 

 committee now announces that this special inquiry is 

 concluded, and that A. plumbeus has been shown to 

 be exclusively sylvan in habits, and to be widely 

 distributed in England, occurring, when searched for, 

 in almost any area in which are found beech, syca- 

 more, chestnut, or other trees with water-containing 

 rot-holes. The committee is now turning its atten- 

 tion to the mating and egg-laying habits of A. 

 plumbeus and other species, which are still imper- 

 fectly known, and invites co-operation from observers 

 in all parts of the country in elucidating these 

 matters. 



Muscarine. — In the Journal of the Chemical 

 Society for September, Dr. Harold King, of the 

 National Institute for Medical Research, records the 

 isolation of muscarine, the highly potent and toxic 

 principle of Amanita muscaria, the Fly Agaric, a 

 common fungus of our birch woods. Muscarine has 

 been the fertile subject of controversy among chemists 

 and pharmacologists for more than fifty years, and it 

 is now shown that the pure material differs essentially 

 from the original claims as to its properties and 

 constitution made by Harnack, upon whose work 

 the whole of the subsequent edifice has been 

 erected. There is no evidence that muscarine is 

 related to choline or is a quaternary base. More 

 than ordinary interest is attached to muscarine owing 

 to its extreme specificity of localisation in the 

 mammalian body and its complete antagonism by 

 atropine. 



A New Spectro-Polarimeter. — Messrs. L. Belling- 

 ham and F. Stanley, Ltd., of 71 Hornsey Rise, have 

 designed and provisionally protected a polarising prism 

 which can be used either in the visible or ultra-violet 

 region of the spectrum. The prism is constructed from 

 one solid piece of Iceland spar cut in such a manner 

 with respect to the crystallographic axis, and of such a 

 length of side, that the extraordinary rav only is 

 transmitted while the ordinary ray is absorbed at 

 the sides. Two such prisms are placed side by side 

 in a suitable mounting. Before being placed in 

 contact the sides of each prism are ground away 

 to give the required length of dividing line between 

 the halves and also to produce the necessary half 

 shadow angle. To provide a sharp face edge one of 

 the prisms is allowed to project in front of the other, 

 and the two are then bound together. It is claimed 

 that such an arrangement is absolutely permanent 

 and that the extinction is perfect. The entire 

 absence of cement relieves the prism of all strain, 

 and eliminates the possibility of light being diffused 

 from particles in the cement or from scratches on 

 the cemented surface. By employing such a polarising 

 prism Messrs. Bellingham and Stanley have been able 

 to construct a polarimeter which can be used either 

 for visual observation, in conjunction with a mercury 

 lamp, or for photographing the entire spectrum 

 between wave-lengths 230U/1 and 800 «j at one 

 exposure. 



CO. 2763, VOL. I IO] 



