338 



NATURE 



[May 13, 1920 



monia, and with seeds soaked in a solution of salt 

 and water, the strength of the solution being the 

 same as that used in the Wolfryn process. After 

 immersion the seeds were dried at 100° F. and then 

 sown. Regarding the tests as a whole, they do not 

 reveal any advantage from seed electrification, the 

 only possible exception occurring in the case of man- 

 golds, where the germination of the electrified seed 

 was 94 per cent., compared with 82 per cent, for the 

 untreated seed and 86 per cent, for the seed soaked 

 in the salt solution, while in the field tests the elec- 

 trified mangold seed yielded 62 lb. per pole more than 

 the untreated seed. In all other cases either the elec- 

 trified seed gave a lower yield than the seeds treated 

 in other ways, or the increase following electrification 

 was so small as to be negligible. 



The Government of India is now considering the 

 principles under which the census of 192 1 is to be 

 undertaken synchronously with those of the nations 

 of civilised Europe. Hitherto the reports have in- 

 cluded much valuable anthropological material, but 

 this is found to be in practice of little value to the 

 bureaucracy. The time, it is said, has come for a 

 scientific demographic census, one which collects such 

 statistical details as will throw light on all the 

 problems of population, such as the causes which 

 increase or decrease peoples or sections of peoples in 

 numbers, by sexes, in efficiency and capacity for 

 progress. More, we want to know the real causes 

 why the Moslem population increases at a faster rate 

 than the Hindu, and the causes of the excess of male 

 births, of the variability of sex mortality, and of poly- 

 gyny and polyandry. To carry out such a scheme it 

 will be necessary to work in close collaboration with 

 European experts. In former census reports the mass 

 of anthropological material made them a happy hunting- 

 ground for European workers. If future reports are 

 to be confined to inquiries of a sociological kind, we 

 trust that efforts will at once be made to continue 

 the ethnological survey on wider lines. The scheme 

 initiated by Lord Curzon has led to little result; 

 and while Madras, the Central Provinces, Burma, and 

 the Punjab have issued some important publications, 

 practically nothing seems to have been done after 

 twenty years' incubation in Bombay, Bengal, and the 

 United Provinces. 



The Meteorological Magazine for April contains an 

 article on "Climates of the British Empire Suitable 

 for the Cultivation of Cotton," by Mr. C. E. P. 

 Brooks. Details with respect to rainfall and tem- 

 perature of a cotton-growing climate are given for 

 various British Possessions and Colonies. It is stated 

 that the essential features are: (i) The mean annual 

 temperature should not be below 60° F. (2) The 

 mean temperature of the warmest month should 

 exceed 80° F., or the mean of the three warmest 

 months should exceed 77° F. to get the best results ; 

 this condition, however, is not so important as the 

 first. (3) The interval between killing frosts (or 

 droughts) should be at least 200 days. (4) The annual 

 rainfall should not exceed about 60 in. for good crops, 

 though cotton of a poorer quality can be grown in 

 much wetter climates; unless irrigation is possible, 

 the annual fall should not be less than 23 in. 

 NO. 2637, VOL. 105] 



(5) There must be plenty of bright sunshine. A dull 

 and humid atmosphere is particularly unfavourable tCK 

 the cotton plant. 



Mr. G. W. Lamplugh's address as president of th& 

 Geological Society of London appears in the Quarterly 

 Journal of that Society, vol. Ixxv., part i, published 

 in January, 1920. Its theme is that studies of the 

 thicknesses of English sedimentary series show that 

 an anticlinal uplift is the sequel 'to deposition in a 

 gradually deepening trough. Hence the greatest 

 thicknesses of strata are now found near the escarp- 

 ments, from which the beds thin away towards the 

 margins of the former trough. The Weald, the 

 Jurassic uplands, the Trias, and most of our Car- 

 boniferous rocks are cited as examples. The Jurassic 

 beds beneath the Weald still retain the synclinal 

 structure; but the "partial recovery" of the trough 

 is marked as we pass upwards through the Wealden 

 series to the Chalk. The sections given provide much 

 material for thought. 



The latest addition to the series of Special Reports 

 on the Mineral Resources of Great Britain, issued 

 by the Geological Survey, is vol. xv. on "Arsenic 

 and Antimony Ores," by Henry Dewey. As 

 neither of these substances is produced in any very 

 important quantities in this country, the report is 

 necessarily a brief one, though the subjects are 

 treated quite thoroughly. Jn the case of each metal 

 there is given a general account of the mode of 

 occurrence and of the distribution of its ores, followed 

 by a detailed description of all the mines that have 

 produced any noteworthy quantity. There is prac- 

 tically no antimony at all produced in Great Britain, 

 but Cornwall and Devon still rank as relatively im- 

 portant contributors to the world's output of arsenic, 

 much of this being obtained as a by-product from 

 Cornish tin-mines. As has been pointed out by Sir 

 Aubrey Strahan, the main value of this report lies 

 in the fact that it has brought together in a con- 

 venient and readily accessible form a quantity of 

 information previously scattered through a number 

 of publications, which is thus rendered readily avail- 

 able to those interested in the various industries which 

 make use of the metals here discussed or of their 

 compounds. 



The April issue of the Journal of the Institution 

 of Electrical Engineers contains the paper read by 

 Mr. R. S. Whipple at the joint meeting of the institu- 

 tion and the electro-therapeutics section of the Royal 

 Society of Medicine on electrical methods of measur- 

 ing body temperatures. After describing the modern 

 resistance thermometer and the thermo-electric couple 

 methods of measuring temperature, he comes to the 

 conclusion that for ordinary work records of body 

 temperature and its variation can best be obtained by 

 means of a resistance thermometer placed in the 

 rectum. For more accurate work a thermo-electric 

 couple with a photographic recorder must be used, 

 especially if rapid or minute variations of tempera- 

 ture are to be detected. The resistance thermometer 

 may be made of platinum wire of about 1/20 mm. 

 diameter, have a resistance of about 140 ohms, and be 

 used with a moving-coil galvanometer in a resistance 



