220 ANNUAL OF SCIENTIFIC DISCOVERY. 



The attention of the chemical world was first prominently called to the 

 fact of the existence of nitrogen in iron and steel by Professor Schafhautl, a 

 translation of whose paper appears in the Philosophical Magazine for 1840. 

 Now, about this period there had arisen some of those new methods in 

 analysis for finding the quantity of nitrogen, that, added to subsequent dis- 

 coveries in the same direction, have given so happy an impulse to analytical 

 chemistry. The method of Dumas of Schafhautl himself of Will and 

 "VVarrentrap, and of Lassigne, were about this time brought into notice ; and 

 Schafhautl, without appearing to have in his mind any theory as to the part 

 played by nitrogen on the composition of steel as distinguished from iron, 

 but knowing that nitrogen was ever present in the manufacture of iron, 

 would appear to have tried his hand at its analytical detection. His results 

 are given with a broadness and an absence of specific details that suggested 

 a repetition of them by the next investigator, Professor R. Marchand, whose 

 essay will be found in the Chemical Gazette for 1850; the latter chemist apply- 

 ing, with considerable ingenuity, the resources of a still more advanced 

 chemistry in refutation of some of the results of the former. To give a still 

 greater zest to the investigations, it had just been discovered by Wohler that 

 those beautiful copper-colored cubic crystals, found in the slags of the blast- 

 furnaces, which we had been accustomed to call titanium, were none other 

 than a mixture of a cyanide and of a nitruet of that metal a fact suggest- 

 ive enough that in iron too there might, not improbably, be discovered 

 some analogous combinations with nitrogen. Schafhautl gives as his 

 results that malleable cast-iron contains 0'532 of nitrogen, close-grained 

 cast-iron 0'927, coarse-grained cast-iron 0'740, white pig-iron 1'SOO, and in 

 Beinhauer's razors 0'532 of nitrogen. Marchand asserts that these propor- 

 tions, are too high, but admits the invariable presence of nitrogen in cast- 

 iron, and its equally invariable absence in malleable iron. Speaking of that 

 method under which the existence of the nitrogen is proved by the forma- 

 tion of Prussian blue, he says that " with steel powder (as compared with 

 cast-iron) it was still more striking, and with soft iron it was never appar- 

 ent." But it is to be observed that it is with cast-iron chiefly, and not with 

 steel, that Marchand operated; still he detects in this cast-iron the invariable 

 presence of nitrogen, and in pure iron its invariable absence. Neither of 

 these chemists speculated as to the meaning or the effect of the presence of 

 the nitrogen in steel; wherever, in the exercise of their manipulatory skill, it 

 is found, the fact is left without comment or consideration. Had the com- 

 parisons been made with pure steel, as with pure iron, there can be no doubt 

 that Marchand would have recognized those marked distinctions which it is 

 the object of the writer to point out. 



Now, suspecting less from such evidences or suggestions of these than 

 from the facts to be observed on conversion (such as that of the singular 

 influence of cyanogen compounds), the substantial and invariable existence 

 of nitrogen in steel, the writer proceeded to arrive at that point as follows : 

 The best malleable iron on the one hand, and by way of comparison with this, 

 the same kind of iron fully converted by the usual process, were taken on 

 trial ; the steel was dissolved in very dilute and pure hydrochloric acid ; and 

 after many trials, it was found best to place the bar of steel or iron in single 

 voltaic arrangement with platinum, and to effect the solution in the cold with 

 the usual precaution of expelling air from the water employed. In this 

 way, slowly, the steel was dissolved, and the carbonaceous flocculent matter 

 that was left, collected, carefully dried, and analyzed. The iron was treated 



