490 



NATURE 



[August 21, 19 19 



During the war the proper provision of life-belts and 

 other life-saving appliances on ships became of vital 

 importance owing to the submarine menace. One of 

 the most widely used appliances was a life-jacket 

 stuffed with "kapok" or floss. This floss has very 

 great buoyancy, a jacket containing 24 oz. of the 

 fibre being capable of supporting an adult in the 

 water. According to the existing official regulations, 

 the only kapok that may be used for this purpose is 

 Java kapok, which consists of the long hair surround- 

 ing the seeds of a tree which occurs abundantly in 

 the Dutch East Indies. A similar material is, how- 

 ever, obtainable from India, but from a different tree, 

 and this Indian floss cannot under the existing 

 regulations be used for life-jackets. The results of 

 trials made at the Imperial Institute, details of which 

 are given in the current issue of the Bulletin of 

 the institute, have shown that the Indian floss 

 can fully satisfy all the requirements as regards 

 buoyancy and freedom from water-logging. It is, 

 therefore, suggested that the use of Indian kapok 

 should be officially permitted for life-jackets. Inquiries 

 made by the Imperial Institute showed that kapok, 

 equal in quality "to that used in the trials, is avail- 

 able in India in large quantities. 



There seemed a prospect but a little while ago of 

 seeing a live okapi in London, for it was known that 

 the Zoglogical Society had made a generous offer for 

 a young animal which had for neariy three vears been 

 the pet of Mme. Landaghem, the wife of a Belgian 

 medical officer stationed several hundred miles above 

 Boma, on the Congo. This, however, was not to be, 

 for Mme. Landaghem has patriotically presented her 

 pet to her native country. It has just arrived in 

 Antwerp, the first of its kind ever seen in Europe. 

 The existence of this remarkable animal was first 

 brought to light, it may be remembered, by Sir Harry 

 Johnston, and through his good offices the first skin 

 and skeleton to reach Europe were those of the female 

 which arrived in London in 190 1. Previous to this 

 he had demonstrated the existence in the Belgian 

 Congo of a large mammal new to science by sending 

 to the Zoological Society of London a bandolier cut from 

 the remarkably striped hindquarters of one of these 

 elusive creatures — elusive because, though the natives 

 had long talked mysteriously of some' strange animal 

 living in the innermost recesses of the forest, and had 

 constantly promised to produce a specimen, that promise 

 was overlong in its fulfilment. This bandolier Dr. 

 P. L. Sclater^»-then secretary to the Zoological Society 

 — 'Concluded had been cut from some species of zebra 

 hitherto unknown, and accordingly bestowed upon it 

 the name Eqtus johnstoni. This seemed warranted 

 by the evidence, but the sequel showed that it was 

 to the giraffes, and not to the horses, that this 

 bizarre-looking animal was related. As vet the sex 

 of the new arrival has not been stated, but if, it should 

 prove to be a male the development of its horns will 

 be watched with interest by all zoologists. 



We learn from the Revue Scientifique that the 

 courses of higher instruction at the Institut d'Optique 

 will be attended each year by selected military and 

 naval officers in addition to university students 

 and others associated with the optical industry. 

 On the industrial side, the full course covering 

 the working of glass and fine mechanics will extend 

 over three years. Subsidies have been promised from 

 the French Government to meet the annual expendi- 

 ture, but an appeal is made for donations towards the 

 initial expenses of the establishment of the institute. 

 The list of members of the council of the institute 

 includes a number of distinguished physicists. 

 NO. 2599, VOL. 103] 



Dr. Arthur Holmes (Quart. Journ. Geol. Soc, 

 London, vol. xliv., p. 31, 1919), in a paper in which 

 field-observation and delicate laboratory studies are 

 happily combined, describes the pre-Cambrian and 

 associated rocks of Mozambique. He utilises radio- 

 activity as a means of correlating the ancient rocks 

 with those of other areas ; the ratio of lead to uranium 

 present assigns the granulitic granites of Mozambique 

 to the Middle pre-Cambrian, and the gneissose granite 

 to a lower series, probably corresponding with the 

 intrusive " Laurentian " rocks of Canada. The com- 

 posite origin of the biotite-gneisses is shown, not only 

 by the field-evidence of assimilation of schists by a 

 granitic magma, but also by a radium-content inter- 

 mediate between that of granites and schists. The 

 lines of " inselberge " in the country are well discussed, 

 and are connected with axes along which the uprising 

 magmas have elongated themselves in the direction of 

 the strike. Though we hesitate to use the phrase " the 

 new geology," Or. Holmes is an exponent of the most 

 recent developments in an old science, which his papers 

 help to keep very much alive. 



Messrs. Posnjak and Merwin {Amer. Journ. Sci., 

 vol. xlvii., p. 311, 1919) provide a critical review of 

 the natural hydrated ferric oxides, stress being laid 

 on the curves that represent the phenomena of experi- 

 mental dehydration. Turgite, which we should now 

 write as turiite, is the only exception to the rule that 

 decomposition takes place in the middle portion of 

 the curve, accompanied by a colour-change from yellow 

 to red. Turiite shows a gradual loss of water, and is, 

 therefore, not regarded as a definite chemical com- 

 pound, but as a solid solution of haematite and gothite 

 with adsorbed water. The authors conclude from the 

 close agreement of the molecular ratio of FejOj and 

 H2O in specimens bearing different mineral names 

 that there is no series of hydrates of ferric oxide in 

 Nature, but that the only existing mineral ferric 

 hydrate is "ferric oxide monohydrate," crystallising 

 polymorphically as gothite and lepidocrocite. Limonite 

 is an "amorphous" condition of the same substance. 

 The fibrous structure that is so common in specimens 

 styled "limonite" indicates some form of crystallisa- 

 tion, and the authors regard the fibrous examples, not 

 as true limonite, but as gothite which has adsorbed 

 capillary water. Both gothite and lepidocrocite are 

 rhombic, the latter having a slightly lower density, 

 and occurring in red, scaly crystals. The authors are 

 able to add some new points to the mineralogical 

 description of this species. 



The question of the degree of roundness of grains 

 of various minerals occurring in sands is interestingly 

 dealt with by Mr. J. J. Galloway (" Rounding of Sand 

 Grains by Solution," Amer. Journ. Sci., vol. xlvii., 

 p. 270, 1919). The author urges that even quartz 

 becomes appreciably rounded in natural waters by 

 solution, and he illustrates experimentally how the 

 smaller grains of a powdered mineral lose their forms 

 and become spheroidal far more quickly than the 

 larger ones. Rapid solution produces grain-surfaces 

 as smooth as glass, while slow solution, of which 

 quartz serves as an example, gives dull surfaces like 

 those due to strong abrasion. Mr. Galloway does not 

 assert that the cause of rounding can be determined 

 in any given case. He shows, however, that we must 

 consider solution as a factor. 



Prof. P. G. H. Bos well summarises his recent work 

 on sands, including the graphic representation of their 

 texture, in a very convenient form by the publication 

 of his inaugural lecture on " Sands : considered Geo- 

 logically and Industrially, under War Condition? " 

 (University Press of Liverpool, 1919, price 15.). 



