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0)1 Metallurgical Phenomena as illustrative of Geology. By 

 Professor Hausmann of Gottingen. Communicated by the 

 Author. (Concluded from Vol. XXIII. p. 330.) 



Of the metallurgic processes there is one in particular, which, 

 in a certain point of view, permits a comparison with that of the 

 process of oxidation which goes on under the crust of the earth, 

 and which, in the present era of our planet, is proclaimed by the 

 phenomena of the still active volcanos — the process of' the pro- 

 duction of malleable iron from crude iron. The crude iron ob- 

 tained in blast furnaces from ores of iron, by the process of 

 reduction and melting, contains iron combined with carbon, 

 and in union with small quantities of various other metals 

 besides (of which manganese is most abundant), of bases of 

 earths, among which silicium is most usually found, and of 

 metalloids, among which sulphur and phosphorus arenotunfre- 

 quently encountered. In order to obtain the purest possible iron 

 from this crude iron, it is melted down in various modes of pre- 

 paration, and heated, when reduced to a state of fusion, by the 

 operation of a bellows or a natural current of air, in such a man- 

 ner, that the atmospherical air may come into the closest pos- 

 sible contact with the crude iron, and, by means of its oxygen, 

 accomplish the oxidation, and, thereby, the separation of the 

 foreign substances combined with the iron. Of these one por- 

 tion, viz. the carbon, escapes in the form of gas, whei-eas an- 

 other is converted into slag. Although the oxygen of the air is 

 combined immediately with the substances which have a greater 

 attraction to it than iron has, it is notwithstanding inevitable 

 that a part of this metal, which exists in such a preponderating 

 quantity, is at the same time oxidized and transferred to the slags. 

 It is, meanwhile, just as comprehensible, that a change takes place 

 in the relation in which the various ingredients of the crude 

 iron is acted on by the oxygen during the continuance of the 

 process, and tliat, consequently, the slags that are produced re- 

 ceive at first a proportionally greater share of earths, especially 

 of silica, than at a later period, whereas they obtain always more 

 of the black oxide of iron the further the process advances. The 

 black oxide of iron, which is constantly accumulating in the 



vol.. XXIV. NO. XLVII.— JANUARY 1838. E 



