May 1 6, 1907] 



NA TURE 



67 



Mr. E. F, Law (I.ondon) dealt with the non-metallic 

 inipurities in steel. His paper is the result of an examin- 

 ation of more than one hundred steels. The impurities 

 have been considered as consisting of five in number, 

 namely, iron sulphide, manganese sulphide, iron silicate, 

 manganese silicate, and iron oxide. Iron sulphide very 

 rarely occurs in commercial steels, and is therefore not 

 considered at length. Manganese sulphide is always 

 present in steel, and is usually harmless. The only 

 instance in which it has been found to exert injurious 

 influence on the quality of the steel is when it segregates 

 with phosphide of iron in the form of " ghosts." Silicates 

 of manganese and iron are frequently found in steel, and 

 are highly injurious to the quality of the metal. In large 

 forgings they sometimes occur in considerable masses, 

 but in rolled steel they are distributed throughout the 

 mass. In either case they are responsible for many 

 failures. No indication of their presence is afforded by 

 ordinary commercial means, and they can only be detected 

 under the microscope. Oxide of iron frequently occurs in 

 Bessemer steel. It occurs in a tinelv divided state, and 

 there is evidence that it is soluble in steel. .\s a general 

 rule, steels which on pickling evince a tendency to blister- 

 ing are high in oxygen. The effect of hydrogen on steel 

 containing oxide is discussed, and experiments were made 

 with the view of determining the temperature at which the 

 oxide is reduced. The results of these experiments tend 

 to show that the oxide is reduced at loo" C. Iron oxide 

 differs from other impurities present in its electrical 

 behaviour, and the influence of this difference on the 

 corrosion of iron and steel is discussed. It has been found 

 that the presence of oxide accelerates corrosion, and 

 corrosion of welded iron affords an illustration of this 

 action. Other instances of the effects of the presence of 

 oxide may be found in the pitting of boiler plates and 

 tubes. 



The last paper on the programme dealt with the nomen- 

 clature of iron and steel. This is the report of an in- 

 fluential committee of the International .Association for 

 Testing Materials which was presented by Prof. H. M. 

 Howe (New York) and Prof. \. Sauveur (Harvard) at the 

 Brussels congress of that association. It was then pro- 

 posed that the report be submitted to the Iron and Steel 

 Institute for consideration, and the secretary will be 

 pleased to receive written comments for publication in the 

 journal. 



The meeting concluded with the usual votes of thanks to 

 the Institution of Civil Engineers, proposed by the presi- 

 dent and seconded by Sir John Alleyne, and to the presi- 

 dent, proposed by Mr. G. Hawksley and seconded by Mr. 

 Saladin (Le Creusot). 



On Friday evening the annual banquet was held, with 

 the president in the chair. Four hundred members were 

 present, and the speakers were the Austrian Ambassador, 

 the Swedish Minister, Sir James Kitson, Mr. Yves Guyot, 

 Admiral Sir Cyprian Bridge, Sir C. E. Howard Vincent, 

 Lord Justice Fletcher Moulton, and Mr. Robert Hammond. 



CHIM.EKOW FISHES. 

 A MEMOIR on " Chima;roid Fishes and their Develop- 

 ■^ ment," by Prof. Bashfnrd Dean, has been issued as 

 Publication No. 32 of the Carnegie Institution of 

 \Va.shington. It begins with a short review of the re- 

 searches in comparative anatomy and palneontology, which 

 led to the view that chima;roid fishes are the most primitive 

 vertebrates or the least modified descendants of the 

 [ ancestral cranium- or jaw-bearing vertebrate ; that, 

 although shark-like, they are nevertheless widely distinct 

 I from the shark ; and that altogether they represent a 

 I lower plane in piscine evolution. 



Admitting the importance of the grounds on which these 

 conclusions were based. Prof. Dean refers to the in- 

 complete nature of the evidence. The material at the dis- 

 Iposal of investigators was inadequate for the solution of 

 the great morphological problems involved, and especially 

 embryological material was extremelv scanty or absent. 

 The author himself failed for several vears in his efforts 

 to obtain satisfactory materials, until his attention was 

 directed by President Jordan to the vicinity of the Hopkins 



NO. 1959, VOL. 76] 



Marine Laboratory at Monterey as .i promising locality 

 for collecting Cbimaera collici. Under the guidance of a 

 Chinese fisherman, Ah Tack Lee, who not only possessed 

 a perfect knowledge of the Chimaera grounds, but proved 

 to be a keen observer of the habits of the fish, the author 

 obtained hundreds of specimens of the adult fish and of 

 ova. Such of the latter as were not required for immediate 

 examination were placed in a case, which was then sunk, 

 attached to a buoy, in water of about five fathoms, to 

 obtain the much needed series of developmental stages. 



After having given an account of the habits and mode 

 of propagation of the Californian Chimfera, the author 

 enters into a full description of its egg and capsule in 

 comparison with the ova of other Chimaeroids. This is 

 followed by a detailed account of the various stages of 

 development of the embryo and of the post-larval growth 

 of the fish. Next the relationships of fossil Holocephales 

 ;u'e considered. In the chapter on organogeny, the dis- 

 cussion of the obscure problem of the development of the 

 dentition ■ and of the homologies of its component parts 

 in living and extinct forms will be studied with particular 

 interest. 



Anatomical, embryological, and pal.xontological evidence, 

 then, appears to the author to be unmistakably in favour 

 of Chimaeroids being widely modified rather than primitive 

 forms. The recent forms retain less perfectly the general 

 characters of the ancestral gnathostome than do living 

 sharks. On the other hand, they have retained several 

 characters of their Pal.'eozoic Selachian ancestors which 

 modern sharks have lost. The ancestral Holocephali 

 diverged from the Selachian stem near or even within 

 the group of the Palaeozoic Cestracionts, and the many 

 features of kinship retained by the recent Chimaeroids and 

 Cestracionts distinctly point at this line of evolution. 



The memoir is illustrated by 144 excellent text-figures 

 and eleven plates. 



BRITANNIC GEOLOGY. 

 "PEW teachers have utilised the study of our own islands 

 to greater advantage than Dr. Joseph H. Cowham, 

 of the Westminster Training College. For thirty years 

 past he has led his pupils over the varied country south 

 of London, and the present writer is one of those who 

 became pleasantly acquainted at an early date with his 

 interest in scenery and his keenness for the details of 

 a landscape. Dr. Cowham has published in " The School 

 Journey " (.Simpkin Marshall, pp. 80, price is.) an account 

 of his methods, illustrated in the country between Croydon 

 and Godstone ; Mr. G. G. Lewis, a former pupil, describes 

 an excursion in the Greenwich and Woolwich area ; and 

 Mr. T. Crashaw, another pupil, shows how a class may 

 study erosion and deposition in river-courses on the banks 

 of the Calder, in Lancashire. These expeditions appear 

 to be wisely accepted as part of the regular school curri- 

 culum, instead of being relegated, as sometimes happens, 

 to the holidays. Their effect in bringing together teacher 

 and taught is rightly insisted on, and cannot be exagger- 

 ated ; and the feelirig is early engendered that the class- 

 instruction in geography relates to something real and 

 natural, which any eye can see and any willing brain can 

 comprehend. 



It is to such teachers, and to their pupils in later 

 vears, that the long-established Geologists' .Association 

 especially appeals. In part x. of its Proceedings 

 (November, iqo6, Stanford, price is. 6d.) Mr. R. S. 

 Herries describes the geology of the Yorkshire coast 

 between Redcar and Robin Hood's Bay, which was the 

 scene of the long excursion of iqo6. Especial interest here 

 attaches to the estuarine representatives of the Middle 

 Jurassic series, with Equisetum coUimnare " found upright 

 in the sandstones as it originally grew," and to the zoning 

 of the Lower Jurassic by the abundant ammonites. The 

 valuable " Sketch of the Geology of the Birmingham 

 District," bv Prof. Lapworth, with a contribution on 

 petrology by Prof. Watts and one on the glaciers by 

 Mr. W. Jerome Harrison, has now been reprinted from 

 the Proceedings of the Geologists' Association for iSqS 

 (Cornish Bros.', Birmingham, pp. viii-Fi04, price 2s. net), 

 and will serve as a guide for generations of students in 



