630 



NATURE. 



[October 29, 1963 



|r, In. Japan the custom prevails of burning down yearly, 

 tri-yearly, or at longer intervals the tracts of ground known 

 as " hara, " this name being applied to the bare hillsides 

 which have been denuded of trees. One of the first pro- 

 ducts on these lands is a grass known as " kaya," 

 Miscanthus sinensis, and it is with the idea of increasing 

 this crop that the lands are burnt. This fallacy is com- 

 bated by Mr. O. Shishido in. the; Bulletin of the College of 

 Agriculture, Tokio, where he points out that the hara, 

 although favourably situated,' are how practicially unpro- 

 ductive areas. In the same journal Mr. H. ShiraWasa 

 indicates the development of the oil in the camphor-tree 

 which crystallises out into camphor. 



A USEFUL little book has been published by the Royal 

 Geographical Society entitled "Hints oh Outfit for 

 Travellers in Tropical Countries," by Dr. Charles F. Har- 

 ford. The hints are of just the practical kind that intend- 

 ing travellers will find serviceable. 



A SIXTH edition of Prof. W. H. Burr's " The Elasticity 

 and Resistance of the Materials of Engineering " has been 

 published by Messrs. John Wiley and Sons, of New York, 

 and Messrs. Chapman and Hall, of London. More than 

 half the book is new, and the advanced matter relating to 

 the general theory of elasticity in amorphous solid bodies, 

 and the theories of torsion and flexure, have been placed 

 at the end of the book as an appendix. 



The Bureau of American Ethnology has published a 

 Natick dictionary compiled by the late Dr. James H. Trum- 

 bull. In an introduction Dr. Edward E. Hale explains 

 that the dictionary is published as it was left by Dr. Trum- 

 bull, whose widow presented the MS. to the American 

 Antiquarian Society. The manuscript was passed to the 

 late Major Powell, who placed it in the hands of Dr. 

 Gatschet, of the ethnologic staff of the Bureau, who has 

 superintended its publication. It is hoped that the book 

 will form the first volume in a series of vocabularies of the 

 native languages. 



It has been shown recently that the composition of the 

 surface layers of a solution differs to a slight extent from 

 the composition of the solution as a whole. Experiments 

 made by Miss C. C. Benson with very dilute amyl alcohol, 

 which readily gives rise to a durable foam on shaking, 

 show that this foam is also different in composition from 

 the main solution, the proportion of alcohol being slightly 

 greater in the foam than in the rest of the liquid. The 

 composition of the solutions was determined by surface 

 tension measurements by the drop method. 



The problem of turning to practical use the free nitrogen 

 of the atmosphere for the purposes of agriculture and 

 industry is one which has excited attention for many years 

 past. According to a recent communication of Dr. Frank, 

 of Charlottenburg, the fixation of atmospheric nitrogen on 

 a technical scale can be effected through the agency of the 

 carbides of the alkaline earth metals. Barium carbide is 

 especially suitable for the purpose, and by the absorption 

 of atmospheric nitrogen is converted directly into barium 

 cyanide. The reaction with calcium carbide proceeds 

 differently, the product obtained being calcium cyanamide, 

 which, however, by heating with water under high pressure 

 is easily converted into calcium carbonate and ammonia. 

 Experiments have, moreover, shown that the calcium 

 cyanamide can be used directly as a means of supplying 

 nitrogen to the soil. 



Although the analogy between asymmetric carbon and 

 nitrogen in regard to optical rotation is assured by the fact 

 that the activity of the nitrogen compounds can be explained 

 by a simple extension of the theory of van 't Hqff and 



NO. 1774, VOL. 68] 



Le Bel, yet previous experiences seem to point to the 

 analogy being very incomplete. The instability and the 

 tendency of the active forms to undergo spontaneous race- 

 misation are conspicuously characteristic of the nitrogen 

 compounds. These properties no doubt depend upon the 

 readiness with which nitrogen passes from the pentavalent 

 into the trivalent form, a transformation which at once 

 destroys the spacial asymmetry. An interesting paper deal- 

 ing with the subject is published by Dr. Wedekind in the 

 current number of the Zeitschrift fUr physikaliscke Chemie. 



An investigation of the best conditions for the electrolytic 

 refining of copper has recently been carried out by Messrs. 

 F. J. Schwab and I. Baum, an account of which is given 

 in the October number of the Journal of Physical Chemistry. 

 The factors which have been taken into consideration are 

 the cost of the power necessary to precipitate a tank of 

 copper with different current densities and at different 

 temperatures, the cost of heating the tank, the deterioration 

 of the electrolyte, the interest charge on the copper in the 

 tank, and the quality of the copper deposited. As the result 

 of a large number of series of experiments, in which the 

 influence of these factors and their correlation were ex- 

 amined, the authors come to the conclusion that in order 

 to operate a plant most economically and to secure the best 

 financial returns, copper should be refined in covered tanks 

 at a temperature of 70° C, with a current density of 3^-3! 

 amperes per square decimetre. 



The additions to the Zoological Society's Gardens during 

 the past week include two Chestnut-breasted Finches 

 (Donacola castaneothorax), a Bicheno's Finch (Estrelda 

 bichenovii), fourteen Banded Grass Finches {Poephila 

 cincta), eight Gouldian Finches {Poephila gouldiae) from 

 Queensland, two Modest Grass Finches {Amadina modesta)^ 

 fourteen Chestnut-eared Finches {Amadina castanotis), two 

 Undulated Grass Parrakeets {Melopsittacus undulatus), a 

 Peaceful Dove {Geopelia tranquilla), a Graceful Ground 

 Dove {Geopelia cuneata) from Australia, presented by Mrs. 

 Alfred H. Houlder ; an American Bittern {Botaurus lenii- 

 ginosus), captured at sea, presented by Mr. Yeo ; two 

 Chameleons {Chamaeleon vulgaris) from North Africa, pre- 

 sented by Mr. G. T. Coleman ; a Hocheur Monkey {Cerco- 

 pithecus nictitans) from West Africa, a Grey Seal {Hali- 

 choerus grypus) from the West Coast of Ireland, a Red- 

 fronted Lemur {Lemur rufifrons) from Madagascar, an 

 Adelaide Parrakeet {Platycercus adelaidae) from Australia, 

 deposited ; two Great Kangaroos {Macropus giganteus) from 

 Australia, a Banded Cotinga {Cotinga cincta) from Brazil, 

 purchased ; a Hybrid Waterbuck, between {Cobus unctuoscf. 

 S and Cobus ellipsiprymnus Q ), born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Astronomical Occurrences in November: — 

 Nov. 3. 3h. 45m. to 7h. 2m. Transit of Jupiter's Sat. III. 

 (Ganymede). 

 7, iih. 23m. Minimum of Algol (3 Persei). 

 9. 8h. 43m. to 9h. 28m. Moon occults \ Geminorum 



(Mag. 36). 

 10. 7h. 26m. to loh. 44m. Transit of Jupiter's Sat. III. 



(Ganymede). 

 ,, 8h. 12m. Minimum of Algol (^ Persei). 

 14-16. Epoch of Leonid Meteors (Radiant 1 50° + 22°). 



15. ih. Venus in conjunction with the Moon. Venus 



0° 55' N. 

 ,, Venus. Illuminated portion of disc =o'429. 



16. 6h. Iim. to 9h. 53m. Transit of Jupiter's Sat. IV. 



(Callisto). 



17. iih. 12m. Transit (ingress) of Jupiter's Sat TIL 



(Ganymede). 

 27. 23h. Venus at great ^t elongation (46° 44' W.}. 

 30. 9h. 55m. Minimum of Algol (3 Persei). 



