February 9, 1893] 



NATURE 



351 



made to pass through the cylinder, a colourless stratum was 

 seen to extend downwards from the surface. The separating 

 surface was sharply defined at first, but after a few minutes a 

 number of secondary stratifications appeared, which on close 

 inspection showed wavy outlines. Many of them were of a 

 deeper blue, i.e. cooler, at their upper than at their lower sur- 

 faces, so that there was evidence of a vortex-like motion in the 

 liquid. For really trustworthy results Mr. Wachsmuth used 

 an arrangement of two copper plates and a thermopile, the 

 lower plate being placed in contact with ice. 



The volume on "The Partition of Africa," by Mr. J. Scott 

 Keltic, which has been for some time in preparation, will be 

 issued in a few days by Mr. Stanford. The work, which has 

 been brought thoroughly up to date, is illustrated by a carefully- 

 selected series of facsimiles of early maps, as well as by a num- 

 ber prepared specially to show the present condition of the 

 continent in its many different aspects. 



Mr. a. E. Shipley, Fellow of Christ's College, Cambridge, 

 and Demonstrator of Comparative Anatomy in the University, 

 has been for some time engaged on an illustrated text-book of 

 invertebrate zoology, which will be published (Adam and 

 Charles Black) early in the spring. It is specially adapted for the 

 use of University students reading for such examinations as the 

 first part of the Natural Sciences Tripos, or for the B.Sc. degree 

 in London. 



Messrs. Macmillan and Co. have published a second 

 edition of Mr. D. E. Jones's "Examples in Physics." The 

 book has been carefully revised, and some sixty pages of matter 

 have been added. New sets of problems from recent papers 

 have been put in the place of the examination questions at the 

 ends of the chapters. 



The first volume of the Seismological Journal is now in the 

 press, and will shortly be issued. It is uniform in size and 

 in character with the Transactions of the Seismological Society, 

 and will correspond with what would have been volume XVII. 

 of those publications had they been continued. The yearly 

 subscription for the journal is 5 yen, 5 dollars, or £\. This 

 includes delivery or postage. It may be paid by P.O.O. or a 

 draft on any foreign bank in Yokohama. Address, John Milne, 

 14, Kaga Yashiki, Tokio. 



Messrs, Whittaker'and Co. have published "The School 

 Calendar and Handbook of Examinations, Scholarships, and 

 Exhibitions, 1893." This is the seventh year of issue. A pre- 

 face is contributed by Mr. F. Storr. 



A DEFINITELY Crystallised compound of iron and tungsten of 

 the composition FeWj is described by Drs. Poleck and Grutzner, 

 of the University of Breslau. The crystals of this interesting 

 substance were discovered in drusy cavities of a massive piece of 

 a crystalline iron-tungsten alloy containing no less than 80 per 

 cent, of tungsten. The alloy had been prepared by an electro- 

 lytic process from wolframite at the works of Biermann's Metal 

 Industry in Hanover, and exhibited in the numerous cavities 

 small but very well-formed crystals of a silver-grey colour and 

 exhibiting very brilliant faces. They were extremely heavy and 

 of exceptional hardness. Upon analysis they yielded numbers 

 corresponding closely with those calculated for the compound 

 FeWj. Dr. Milch, of the Mineralogical Department of the 

 University, subjected the crystals to a goniometrical investiga- 

 tion, and found them to consist of trigonal prisms whose faces 

 were inclined exactly at 60", and which were terminated by a 

 basal plane inclined exactly at 90°. Singularly, however, no 

 other faces were ever discovered upon them, so that it was im- 

 possible to ascertain to what sub-section of the hexagonal system 

 the crystals belonged. The crystals are so hard that they readily 

 scratch topaz, and appear to be of about the same hardness as 

 corundum. 



NO. I 2 15. VOL. 47] 



The discovery of these crystals of a definite compound of 

 iron and tungsten, and the fact that they are endowed with such 

 a high degree of hardness, afford a ready explanation of the long- 

 known property of tungsten in improving the hardness of steel. 

 Berzelius, in his Lehrbuch, already remarked that tungsten 

 readily formed alloys with most of the other metals, and in the 

 year 1858 Muchet in this country took out a patent for the em- 

 ployment of tungsten in the manufacture of steel. Thereupon 

 the wolfram minerals, previously considered as almost worthless, 

 rapidly came to acquire a considerable value. Bernoulli has 

 since shown that tungsten is capable of alloying in all propor- 

 tions with iron until it reaches a proportion of 80 per cent., when 

 the mass becomes infusible even at the hottest procurable white 

 heat. This alloy containing so high a percentage of tungsten, 

 approximating indeed to that (86-4) contained in the crystals 

 above described, exhibits a silver-grey lustre like that of the 

 crystals and possesses almost the same hardness, scratching 

 glass and quartz with ease. Latterly the manufacture of this 

 alloy has been carried on at the Hanoverian metal works above 

 referred to, and brought into commerce. There can be little 

 doubt that the remarkable property of tungsten in increasing the 

 hardness of steel is due to the formation of more or less of this 

 compound FeWa, and the nearer the proportions of the two 

 metals approach to those of the compound itself the more nearly 

 does the resulting alloy approach in hardness to that displayed 

 by the crystals of FeWj above described. 



The additions to the Zoological Society's Gardens during the 

 past week include a Macaque Monkey {Macacus cynomolgus, 9 ) 

 from India, presented by Capt. U. Cooke ; a Two-spotted 

 Paradoxure {Natidinia binotata) from West Africa, presented by 

 Lady Fleming ; a Brush-tailed Kangaroo {Petrogale penicillata, 

 6 ), two Black-striped Wallabys {Halinaturiis dorsalis, 9 ? ) 

 from New South Wales, presented by Mr. Wilberforce Bryant ; 

 a Mange's Dasyure {Dasyurus maugaei) from Australia, pre- 

 sented by Mr. Robert Hoare ; a Red and Yellow Macaw {Ara 

 chloroptera) from South America, presented by Mr. H. H. 

 Dobree ; a Grey Parrot (Psiftactis eritkacus) from West Africa, 

 presented by the Executor of the late Mrs, Bolaffe ; an 

 Ethiopian Wart Hog {Phacochcerus cethiopicus, 6 ) from Mata- 

 beleland, South Africa, deposited ; two Chukar Partridges 

 {Caccabis chukar,^i ?) from North-west India, presented by 

 Major Ingoldsby Smythe ; fourteen Prairie Marmots (Cynomys 

 ludovicianus, 6 cJ 8 ? ) from North America, an Arctic Fox 

 {Canis lagopus) from the Arctic Regions, two Rufous Tinamous 

 (Rhynchoius rufescens) from Brazil, purchased ; three Black 

 and Yellow Cyclodus {Cyclodus nigro-luteus), three Diamond 

 Snakes {Morelia spiloUs), a Short Death Adder {Hoplocephalus 

 curtus), a Purplish Death Adder {Pseudechis porphyriaca), a 

 North Australian Banded Snake {Pseudonaia nuchalis) from 

 New South Wales, received in exchange. 



OUR ASTRONOMICAL COLUMN. 



Comet Holmes (1892 III.). — During the past week no 

 very important change has taken place in the appearance of the 

 comet ; the following is the current ephemeris :— 

 Ephemeris for xzh. M. T. Paris. 

 1893. R.A. app. Decl. app. 



h. m. s. o / // 



Feb. 9 ... I 56 293 ...-1-34 o 28 



10 ... I 58 33 ... 2 18 



11 ... I 59 378 ... 4 12 



12 ... 2 I 12-8 ... 6 9 



13 ... 2 483 ... 8 9 



14 ... 4 24'4 ... 10 13 



15 ... 6 o*9 ... 12 20 



16 ... 2 7 379 - 34 14 30 



Mr. Fowler writes from South Kensington : — " The comet on 

 February 6 was a very dim nebulosity without sensible nucleus." 



