35^ Oil in crude Iron.'^Naiive Iron of Peru, 



ftronger proof, continues M. Prouft, that the phofphuret of carbon Is a combination 

 formed by virtue of the laws of affinity, than its unchangeablenefs by the folution of cauftic 

 pot-afli, even with the afliftance of heat. Time did not permit the author to determine the 

 proportions of the elements of the phofphuret of carbon. He promifes a plentiful harveft 

 of new fa£ts to thofe who may be difpofed to purfue this fubjeft, and follow its combina- 

 tions witli metals and other combuflible bodies. 



On this occafion M. Prouft corredts or recalls an opinion which was given in the 

 Journal des Mines, refpe£ling the fmell of hydrogen gas which becomes difengaged during 

 the folution of certain kinds of caft iron and fteel in acids. He conceives that it is 

 owing to the prefence of an eflential oil rather than to that of phofphorus, as had been 

 fufpeded. He gives the following obfervations in fupport of his prefent notion: i°. 

 The neck of the matrafles, retorts, and receivers, in which the inflammable gas is pre- 

 pared, are greafed with little drops of this oil. 2°. If ij ounces of black crude iron be 

 diflblved in fulphuric or muriatic acid, drops of oil are obferved floating on the water of 

 the receiver- 3°. If the waflied carburets, which are obtained from crude iron, be gently 

 diftilled, water comes over along with an oil of the fame fmell ; and alcohol, in which 

 fuch crude iron has been macerated (in powder) becomes white on the addition of water. 

 , M. Prouft thinks that if the inflammable gas, which is obtained from crude iron, were 

 carefully examined, it would be found to hold oil in folution, and that it is this fubftance 

 which gives it Its fetid fmell. If the faft be accurately fo, of which we have no doubt, it 

 is, as M. Prouft obferves, a grand ftep towards the explanation of the phenomena of 

 vegetation, and the underftanding the tranfition of mineral fubftances into vegetable 

 products. 



M. Prouft thence pafles to the examination of the native of the iron of Peru. This 

 fpecies of iron, which has been noticed by Rubin de Cells, is of a greyifh white colour. 

 It bears a rather ftrong refemblance to certain native filvers, for which it was for fome 

 time miftaken. It poflx;fl"es a confiderable degree of du£Hlity, docs not ruft like common 

 iron, and has nearly the fame habitude under the file. 



5.31 grammes (100 grains) of this iron, diflblved in fulphuric acid, only aflx)rded 3520 

 centimetres (176 Fr. inches) of hydrogen gas; whilft the fame quantity of common iron 

 wire gave 200 inches. At the commencement of the folution, a fmali quantity of car- 

 bonate of iron was feparated, which difappeared towards the end. 



The colour of the folution, which was much greener than ufual, led M. Prouft to fuf- 

 pe£l that there was copper in this iron ; but fulphurated hydrogen not having precipitated 

 any thing, and the liquid having prefer ved the fame colour as before, it appeared to him 

 that no other fubftance but nickel could produce thefe effefts. In order to have a certain 

 proof of this, he oxided the iron ftrongly by means of nitric acid, and afterwards pre- 

 cipitated it by the gradual addition of pot-afli. The iron being thus feparated, the green 

 colour of the liquid afl'umed a greater degree of intenfity, and by completing the pre- 

 cipitation, after filtering, he obtained a fubftance xvhich, with fulphuric acid, yielded 

 3 fulphate 



