578 



NA rURE 



[October 15, 1896 



appears to be quite insufficient to support this serious charge. 

 The results of an inquiry into the alleged liability of wood 

 charcoal to spontaneous combustion, by Mr. W. D. A. Bost, 

 have been published in a slender volume by Mr. Alexander 

 Gardner. The fact of the matter seems to be that though 

 freshly-made charcoal — tliat is, charcoal which has not absorbed 

 its moisture — and oxygen is liable to so-called spontaneous com- 

 bustion ; it is never liable to re-ignite after having been exposed 

 to the air for a few days. In any case, it seems that if after a 

 few days no fire shows itself, the charcoal may be regarded as 

 safe. The scare arising from the supposed danger from the 

 ignition of charcoal used in insulating refrigerating chambers 

 may, therefore, be regarded as groundless. 



There appears to be no grounds for the statement made by 

 Herr Schmeltz in the Interimtioiiaks Archiv fur Ethnografiltie, 

 and referred to in Nature, July 9, p. 237, that the Government 

 of New Zealand had developed a sense of prudery in regard to 

 the ithyphallic idols and figures in the Auckland Museum. Mv. 

 T. F. Cheeseman, the Curator of the Museum, informs us that 

 no idols whatever have been mutilated since the Museum has 

 been under his charge, and the ethnographical collections have 

 been almost wholly formed since his appointment. There are 

 two or three large mutilated figures in the Museum, but that 

 was done long before they came into the Museum, and probably 

 dates from the period of missionary activity in New Zealand. 

 Mr. Cheeseman very much doubts the accuracy of Herr 

 Schmeltz's statement respecting the restriction of the importa- 

 tion of the phallic chalk figures from New Zealand. For many 

 years such specimens have been on exhibition at the Auckland 

 Museum, without objections being raised by the Government or 

 any one else. 



.\t the last meeting of the American Institute of Jlining 

 Engineers, held at Denver in September, one of the most interest- 

 ing papers read was on the " Micro-structure of Steel and the 

 Current Theories of Hardening," by A. Sauveur. Mr. Sauveur 

 recognises only four constituents of steel, viz. ferrite or pure 

 iron ; cementite or Fe^C, isolated by Abel in 1S55 ; pearlyte, an 

 extremely intimate mixture of ferrite and cementite, arranged 

 either in lamellre or granules ; and martensite, the composition 

 of which cannot be determined by the microscope. Martensite 

 exists only in hardened steel at ordinary temperatures, and is 

 converted into pearlyte in the process of annealing. It appears 

 to correspond with Arnold's hypothetical subcarbide, Fe.^jC ; but 

 inasmuch as it is of variable composition, containing as little as 

 012 per cent, of carbon in very mild steel after quenching, and 

 as much as 0"90 per cent, in hard steel, it follows that no single 

 formula can express its composition. Mr. Sauveur is also dis- 

 satisfied with the allotropic theory of the hardening of steel, 

 mainly on two grounds. First, he observes that the allotropists say 

 that the iron passes from the hard 3 to the soft a state on cooling 

 through the critical point Ar^, and consequently iron quenched 

 between Ar, and Arj should be soft, while Mr. Howe has 

 shown that it is hard. Secondly, according to the allotropic 

 theory, slowly cooled non-magnetic manganese steel should be 

 harder than quenched carbon steel ; while, on the contrary, it is 

 far less hard than steel containing much carbon. Mr. Sauveur 

 suggests that the absorption or evolution of heat at the critical 

 points is due to the structural changes which occur at these 

 points. This seems to differ hardly at all from the views of the 

 allotropists, for it is next to impossible to exclude structural 

 changes, accompanied by thermal disturbances, from the list of 

 allotropic changes. Lastly, Mr. Sauveur attributes the hardening 

 of steel to the existence of a network of minute plates of FcjC 

 disseminated through the mass ; a view which will assuredly not 

 put an end to the violent controversy which rages round this 

 point, if indeed it meets with any support at all. 

 NO. 1407, VOL. 54] 



The reference, in our last issue, to the first number of // 

 Naturalisia Siciliano should have been to the first number of a 

 new series of that periodical, which has been published con- 

 tinuously since 1S82. 



Many naturalists may be glad to know that Mr. R. II. 

 Porter, Cavendish Square, London, has just published a cata- 

 logue containing nearly four thousand titles of new and 

 second-hand books on natural history offered for sale by him. 



We have received the Proceedings of the Natural History 

 Society " Isis " of Dresden, for 1895, which is almost entirely 

 occupied by a paper by the editor. Dr. O. Drude, on the dis- 

 tribution of eastern plants in the Flora of the Saxon Elbe- 

 valley. 



TuF. Division of Vegetaljle Physiology and Pathology of the 

 U.S. Dep.irtment of Agriculture has issued an important paper 

 by Mr. W. T. Swingle [Bulletin No. 9), on the use ot 

 " Bordeaux mixture," a mixture of copper sulphate and lime, 

 as a fungicide for vegetable crops. 



Mr. J. W. Marriott has taken all the questions contained 

 in the papers set by the Department of Science and Art in 

 Practical, Plane, and Solid Geometry since 1SS4, and has 

 arranged them on a graduated scheme, so that they can be used 

 as exercises upon the various sections of the departmental 

 syllabus. This graduated arrangement under different headings, 

 and the lithographed diagrams accompanying the questions, 

 should be of assistance to teachers of the subject. The ques- 

 tions are published in two sets — Elementary and .VU^anced — by 

 Mr. E. Coward, Blackburn. 



The M eteorological Institute of Copenhagen has just 

 distributed an important summary of llie meteorological 

 observations made in that city during the years 1751-1893. 

 This period embraces no less than 143 years ; but from various 

 causes, the results of several of the intermediate years are miss- 

 ing, and the observations have naturally been taken at various 

 hours and localities. Since 1 874 they have been made under the 

 immediate superintendence of the Institute, and consequently 

 these possess a much higher value than the earlier series. The 

 annual temperature varied between 49'3° and 41 2'. The mean 

 annual rainfall was 22 'i inches. The summer is the wettest 

 season ; the winter and spring being much dryer than the other 

 seasons. The author {Mr. V. Willaume) discusses the data 

 from various points of view, e.g. their possible connection with 

 sun-spots, and the moon's influence. 



The Proceedings of the Rochester (New Vork) Academy ot 

 Science, Brochure i. of vol. iii. of which has lately come to 

 hand, is a pleasing production, and is a proof that no pains 

 or expense are spared to make it thoroughly attractive in 

 appearance. The section before us is occupied by a paper by 

 Florence Beckwith and Mary E. Macauley, assisted by Joseph 

 B. Fuller, on " Plants of Munroe County, New York, and 

 adjacent territory." The list aims at the inclusion of the 

 names of plants growing without cultivation in Munroe and 

 adjoining counties, and care has been exercised in the deter- 

 mination of specimens, the authors having excluded all those 

 concerning which there have been reasonable doubts. .\ 

 general comparison is given of the Munroe flora, with lists of 

 plants covering territory east and west of the area under dis- 

 cussion, i.e. the territory of Buffalo and the area of Cayuga, 

 and the result as given by them is as follows : The total number 

 of species enumerated in the Buffalo list is 12S9, that in the 

 Cayuga flora is 1278, and that in the Munroe list is 1309. The 

 paper is illustrated by a map of the region discussed, and by a 

 diagram showing the stratigraphy of the same. 



