April 25, 1901] 



NA TURE 



619 



ice-forming layer is one of extreme thinness just at the surface, 

 and that in observing with the ordinary thermometer this layer 

 gets mixed with the warmer water underneath. 



A MATHEMATICAL investigation of the motions of seismo- 

 graphs, which from its nature bids fair to have important 

 applications, is published by Dr. M. Contarini in the Atti del 

 Lincei, x. 5, 6. In it the author determines the differential 

 equations regulating the motion of the forms of seismograph 

 considered relative to three rectangular axes, and shows how 

 these equations may be integrated. The assumption on which 

 this work is based is that all the points of attachment, both of 

 the pendular masses and of the registering levers, are treated as 

 being rigidly connected with the earth. 



In ih& Bulletin of the Cracow Academy, November 1900, 

 Herr Zorawski studies the motion of a continuous system of 

 material points regarded as a group with the infinitesimal trans- 

 formation determined by the well-known operator of the 

 ordinary equations of hydrodynamics. It appears that if the 

 characteristic equation possesses three distinct roots, the principal 

 axes of the quadric connecting the rates of strain are transformed 

 into principal axes, if two roots of the characteristic equation 

 are equal only one principal axis is transformed into a principal 

 axis, finally, in the case of a triple root, the line element possesses 

 properties which the author designates as "perfectly sym- 

 metrical." 



The resistance of cereal smuts to formalin and hot] water 

 forms the subject of a short paper by Mr. William Stuart in the 

 Proceedings for 1898 of the Indiana Academy of Science, which 

 has recently reached us. The results obtained in the treatment of 

 the spores are well within the bounds of successful practice, the 

 spores being much more easily injured with either hot water or 

 formalin than is the grain. It is apparent that the essential feature 

 in the successful treatment of grain for smut is to bring each seed 

 in contact with the solution used for a sufficent length of time 

 to enable it to reach the spores. The advantage possessed by 

 formalin over hot water in the treatment of seed grain lies in its 

 greater ease of application, doing away with the necessity of 

 heating water and maintaining a sufficiently uniform temperature 

 during the treatment. Mr. Mason B. Thomas describes some 

 field experiments with formalin in the same volume. 



Part 67 of the Communications from the Leyden Physical 

 Laboratory contains a paper by J. C. Schalkwijk on precise 

 isothermals, in which the author describes methods of determin- 

 ing the corrections to be applied in taking account of the volume 

 of the meniscus of mercury in working with standard gas- 

 manometers. 



A DISCUSSION on the properties of steel containing nickel is 

 presented to the Report of the Congres International des 

 Methodes d'Essai (Paris, 1900). In passing from ordinary 

 steel to that containing a considerable proportion of nickel the 

 principal changes are the lowering of the temperature of trans- 

 formation of the carbon, the fusion of two of the transforma- 

 tions and the exaggeration of the phenomena accompanying the 

 double point. In ferro-nickels containing traces of carbon, but 

 more than 20 per cent, of nickel, the transformations are deter- 

 mined by the nickel, the carbon acting as a retardent. It 

 appears that the magnetic properties are due to a certain mole- 

 cular transformation which takes place with evolution of heat, 

 and when this molecular grouping is prevented by the presence 

 of some other body, the metal may be reduced to ordinary tem- 

 peratures without exhibiting magnetic phenomena. The author 

 compares ferro-nickels to solutions rather than combinations. 

 Finally, it is suggested that by the addition of nickel many pro- 

 perties of steel may be studied at temperatures considerably 



NO. 1643, ^O^- ^3] 



below those at which they occur in pure steel. As an example 

 the author mentions the gradual changes of volume which take 

 place in the course of years, and which in the case of nickel 

 steels may be observed at the temperature of the laboratory, 

 whereas it would be impossible to study similar changes occurring 

 at an elevated temperature in pure steel. 



In the April number of the Zoologist Mr. J. H. Gurney 

 mentions that the nestling of the green woodpecker, when a 

 few days old, develops a pea-like knob on each side of the 

 hinder part of the mandible. It would be interesting to discover 

 the use of this peculiar growth, which appears to have been 

 hitherto unnoticed. 



A LARGE portion of vol. xxii. part 3 of Notes from the 

 Leyden Museum is taken up by instalments of Dr. O. Finsch's 

 catalogue of the birds in the collection ; these deal with certain 

 eagles, the parrots of the South Sea islands, and various 

 passerines. Another article, by Dr. Jentink, treats of certain 

 alleged errors in the description of the large West African 

 diuker antelope {Cephalophus sylvicultor). Considering .that 

 one of the articles is dated March 1901, it is somewhat difficult 

 to understand why this part of the Notes is issued for Julj' 1900. 



Part 3 of vol. Ixix. of the Zeitschrift fUr wissenschaftliche 

 Zoologie contains six memoirs, five of which deal with the 

 anatomy and morphology of invertebrates, while the sixth (by 

 Herr E. Botezat) treats of the nerves of the hard palate of 

 mammals, a subject which has hitherto received but little atten- 

 tion from anatomists. To specialists, Prof. F. Vejdovsky's 

 communication on the morphology of the antennae and shell- 

 glands of the Crustacea should prove interesting. Another 

 paper, by Herr N. Kassianow, deals with the nervous system 

 of the lucernarian medusae. 



The concluding portion of Mr. E. J. B. Sopp's address on 

 the importance of the study of life-history among insects is 

 published in the Ento/nologist for April. After mentioning 

 that insects in captivity are often somewhat misleading in their 

 habits, and that all observations should be verified on specimens 

 in the wild condition, the author cites a few instances where 

 our ignorance of insect physiology is most noticeable. It is 

 quite unknown, for example, how the water-beetles of the 

 genus Dytiscus produce their well-known stridulating sound. 

 Neither do we know the use of the peculiar cord-like structure 

 found in "bloodworms," or larvae of the gnat-like fly Chiro- 

 nomus plumosus, nor how the respiratory air-sacs of the 

 "phantom larvae" of another gnat, Corethra plumicornis, 

 become inflated with air, and that, too, in all probability of a 

 highly oxygenated character. The author also calls attention 

 to the importance of coalition between natural history societies 

 for the purpose of recording the local abundance of insects in 

 their respective districts. It is the common and not the rare 

 species to which attention should be directed, as by this means 

 we may in time be able to predict and thus prevent the appear- 

 ance of " plagues" of noxious kinds. 



A descriptive catalogue of the Coleoptera of South Africa, 

 by Mr. L. Peringuey, assistant director of the South African 

 Museum, constitutes vol. xii. of the Transactions of the South 

 African Philosophical Society. The catalogue occupies 563 

 pages, and is illustrated by nine plates. 



We have received a copy of Electrical Investments, a new 

 fortnightly journal devoted mainly to the financial side 01 

 electrical undertakings. Besides an extensive share list, the 

 paper contains a leading article and comments on matters of 

 interest to those concerned, financially or otherwise, with 

 electrical matters. 



