Sept. II, 1879] 



NATURE 



469 



One remarkable fact is that, after the conversion of the iron, a 

 quantity of the charcoal, in the converting pots, is found in a 

 pulverised state, so as to be unfit for further use. 



Some of this waste charcoal the writer has examined, and from 

 one sample, by the aid of a magnet, he succeeded in extracting 

 5 to 6 per cent, of iron scale, and small pieces of steel, these on 

 being treated with dilute hydrochloric acid, evolved considerable 

 quantities of sulphuretted hydrogen ; in one case he estimated 

 the quantity of sulphur, and found it to contain as much as I '25 

 per cent, of this element. 



The steel is now broken up into small pieces and melted in 

 crucibles, and cast into ingots. These are sent to the forge, 

 where they are heated and rolled. In this part of the process 

 the chief difficulty with which the silter has to contend is the 

 porous or "honey-combed" structure of the steel. 



One of the characteristic features relied on by practical men 

 as indicating the quality of a piece of steel is the appearance of 

 its fracture ; but this is by no means an infallible test, as the 

 fineness or coarseness of grain can be produced by mechanical 

 treatment or chemical means. 



The characteristic property possessed by steel is its capability 

 of being hardened and tempered. The temper of cast steel may 

 be said to range from 0*75 to I '50 per cent, carbon. The 

 temper of steel is an important question in connection with the 

 purpose for which it is required ; thus a steel containing i "50 per 

 cent, of carbon is the class employed for razors. i"25 per cent. 

 is that known as " tool temper." Steel containing 1 "oo per cent. 

 carbon is termed "chisel steel," and this temper is extensively 

 used in the arts. 



The latter part of the paper is occupied with the consideration 

 of the manner in which bodies such as carbon, silicon, sulphur, 

 phosphorus, and manganese, affect the quality and mechanical 

 properties of the steel. 



A Lecture ExferimnH in Illustration of the Holkvay Process of 

 Smelting Sulphide Ores, by Alfred H. Allen. — By causing oxy- 

 gen gas to bubble through molten antimony sulphide contained 

 in a V-shaped piece of combustion-tube, combustion takes place 

 with such rise of temperature as to soften the glass, while a sub- 

 limate is obtained of antimonious oxide, and sulphurous acid 

 gas is evolved. The sublimate is collected in an empty globe, 

 and the sulphurous acid is absorbed by passing it into a large 

 vessel containing lumps of wood-charcoal. At the conclusion 

 of the experiment the contents of the combustion-tube may be 

 poured out, when a button of metallic antimony free from 

 sulphur is obtained. 



By passing oxygen over lumps of pyrites contained in a 

 heated combustion-tube, vivid combustion takes place, much 

 free sulphur sublimes, and sulphurous acid gas is obtained and 

 absorbed as before described. 



On the Presence of Nitrogen in Steel, by Alfred H. Allen. — 

 The author made some preliminary experiments on the subject 

 in 1872, but has only recently obtained any definite results. The 

 method adopted has been to dissolve the steel in hydrochloric 

 acid, by which means any combined nitrogen may be presumed 

 to be converted into ammonia. The solution obtained was than 

 distilled with excess of lime, and the distillate examined for 

 ammonia by Nessler's method. The employment of this ex- 

 tremely delicate te-,t enabled the author to operate on a much 

 smaller quantity of steel than was employed by previous investi- 

 gators. Very special precautions were taken to obtain the 

 hydrochloric acid and other materials free from any trace of 

 ammonia or nitrous compounds, and the air was entirely ex- 

 pelled from the apparatus before commencing the operation. 

 Thehydrogen evolved was freed froai any traces of ammonia l^y 

 passing it through a tube filled with glass beads moistened with 

 hydrochloric acid. It was proved by blank experiments that no 

 source of ammonia existed in the reagents or apparatus. 



When absolutely pure materials were used, and every precau- 

 tion taken to get rid of the contained air and other sources of 

 error, the addition of Nessler's solution to the liquid obtained on 

 distilling with lime caused a very marked yellowish-brown 

 coloration. 



The author then gives the amount of nitrogen determined by 

 his method in different varieties of steel. 



In order to obtain ammonia in quantity'sufficient for its recogni. 

 tion by other reactions than that with Nessler's test, the follow- 

 ing plan was employed : — 



Steam, generated by boiling water in a flask, was passed over 

 a considerable quantity of steel borings contained in a combustion 

 tube which was bent beyond the furnace, and prolonged so as to 



form the inner tube of a Liebig's condenser. To the further 

 end, a tube filled with glass beads and furnished with a glass 

 stopcock was attached. A rapid current of steam was driven 

 through the apparatus for a considerable time to expel every 

 trace of air. On condensing the steam it was found free from 

 any trace of ammonia. The steel borings were then heated to 

 redness by a combustion furnace, and a rapid current of water 

 passed through the condenser. The condensed steam, when 

 tested by Nessler's solution, was found to contain abundance of 

 ammonia, which did not diminish in amount till the borings were 

 almost entirely oxidised. On redistilling the condensed steam, 

 a distillate was obtained, having a distinctly alkaline reaction to 

 litmus paper, and on treating it with hydrochloric acid and 

 platinic chloride a sensible amount of yellow precipitate was 

 obtained, having the characteristic crystalline form of ammo- 

 nium chloroplatinate. The amount found was larger than could 

 possibly have been produced had the whole of the nitrogen of 

 any residual trace of air been converted into ammonia. 



The author regards the results now recorded as preliminary 

 merely, and proposes to extend the research to various classes of 

 steel and iron, and especially to such specimens as have been 

 found to possess anomalous characters. Of these, the evolution 

 of ammonia from freshly fractured surfaces is the most striking. 



On the Separation of Phosphorus in Steel Manufacture, by 

 Thomas Blair. — He said the complete removal of phosphorus 

 from pig-iron is of the utmost importance to this country, 

 as the greater portion of ores raised and iron made here is 

 unfit for the manufacture of steel by the Bessemer processes. 

 A history of the various processes made use of for the purpose 

 were examined in detail, especially the processes of Messrs. Bell, 

 Thomas, and Gilchrist. The writer concluded that this latter 

 process was in a fair way to succeed commercially, and that it 

 seemed only necessary to effectually remove a few remaining 

 difficulties. 



SECTION C— Geology 



On the Coal Fields and Coal Production of India, by V. Ball, 

 M.A., F.G.S., of the Geological Survey of India. — The coal- 

 bearing rocks of Peninsular India are all included within the 

 limits of the great series of plant-bearing rocks to which the term 

 Gondwana has been applied, and they are further limited to two 

 groups of rocks which occur in the lower portion of that series. 



By some authorities the age of these Gondwana rocks is 

 supposed to be equivalent to that of the European formations 

 which range between and include the lower oolite and the base 

 of the trias (Buntsandstein). By others the lower measures, 

 including the coal, are believed to be palxozoic. The author 

 proceeded to give an outline of the recent discussions on this 

 subject, referring particularly to Mr. W. T. Blandford's judicial 

 summary of the evidence in the lately issued " Manual of the 

 Geology of India." 



The distribution of the coal-bearing areas was then pointed 

 out on a series of maps which were exhibited, and the number 

 of. distinct coal-fields was stated to amount to about thirty. 

 Some details were then given regarding these fields, of which 

 five only are worked at present, namely, Kanigunj, Kurhurbali, 

 and Daltongunj in Bengal, and Mopani and Warora in the 

 Central Provinces. 



The total area of the Indian coal-fields is estimated by Mr. 

 Huglies at upwards of 30,000 square miles. Three countries 

 alone contain larger areas, viz., the United States 500,000, China 

 400,000, Australia 240,000. 



In quality the Indian coals arc inferior to the average of 

 English and Australian ; but they are capable of accomplishing 

 good work in locomotives, and for this purpose they are largely 

 employed on the main lines of railway in India — Indian coal 

 mixed in equal proportion with English. 



The author proceeded to give further details as to the quality 

 of the coal, stating that the anthracite varieties were rare, the 

 general character being bituminous and the structure laminated — 

 bright and dull layers alternating. 



In round figures it may be stated that at present i,ooo,coo 

 tons of coal are consumed in British India per annum in loco- 

 motives and factories, the quantity employed in the form of 

 coke for domestic purposes being inconsiderable ; and that of 

 this 1,000,000 tons, about one-half is raised from Indian mines, 

 the other coming from England, France, and Australia. 



On the Keuper Beds between Retford and Gainsborough, by 

 F. M. Burton, F.G.S.— After describing the general position of 



