48 ANNUAL OF SCIENTIFIC DISCOVERY. 



to be to such an extent as would render it available in the arts, for so 

 quickly cooled is the iron that the decomposition is so small as to be 

 nearly imperceptible. 



We could reasonably infer, if the superheated steam was decom- 

 posed by contact with the molten iron, that an oxy-hydrogen mixture 

 on a grand scale would be formed, and a small volcano, generating an 

 intense heat, be created. In order to modify this intensity, ordinary 

 steam could have been introduced along with the superheated steam, 

 then the heat generated would be under the control of the operator. 

 We tried melting the. iron under the llame of the oxy-hydrogen blow- 

 pipe ; a bead was formed, which was metallic iron encased in a shell 

 of oxide of iron. Here there is another point to be vieAved, viz : the 

 iron in the mixed gases is rapidly oxidized, and loss of metal to a 

 great extent incurred. Unfortunately for the iron manufacturers, the 

 play of affinities between the elements of steam and iron, with its im- 

 purity, are in the wrong direction ; combustion is not accelerated, 

 chemical decompositions do not set in, from the fact that the tempera- 

 ture is rapidly lowered, for reasons already given. Since making the 

 above experiments, information relative to the patent lately taken out 

 by Mr. Parry, of England, on this subject, has rcache'd us. His 

 method is to introduce steam as well as air into the molten iron. The 

 steam is introduced until the metal is brought to a semi-fluid consisten- 

 cy, and then shut off, and air forced through, which again increases 

 the temperature, these alternate exposures of the molten metal con- 

 ducing to desulphurize and purify the metal. From the experiments 

 we have already detailed, we are forced to conclude that the super- 

 heated steam claimed by Mr. Parry to purify the metal, has had at- 

 tributed to it the benefits derived from the air blown through ; and he 

 has unwittingly placed to the credit of the steam, what should have 

 been credited to air. With all the facts we have learned from other 

 sources, added to those we have derived from practical experiment, 

 we are of the opinion that, as yet, the pneumatic or Bessemer process 

 is superior as regards economy, practical working, and ease with which 

 it is managed. We are also led to the firm conviction, deduced from 

 our experiments, that the role played by superheated steam, is a mere 

 imaginary one ; it does not desulphurize to any extent, or to one half 

 the rapidity that the pneumatic process does ; but, in fact, if any 

 chemical action takes place, it is the oxidation of the metal. 



These results are submitted, and are not intended to cast a blight 

 on future experiments, but to show that steam or superheated steam 

 does not play such an important part in the iron manufacture as many 

 have supposed. 



THE PRESERVATION OF METALS. 



The preservation of copper and iron in the sea has been made the 

 subject of long research by M. Becquerel, who has submitted a 

 memoir to the Academy of Sciences at Paris. The causes of the in- 

 jury (mechanical, physical, and chemical) influence, all the chemical 

 actions and tend to the production of electricity by means of isolated 

 voltaic pairs. After considering the important experiments of Davy 

 and others in regard to copper sheathing, M. Becquerel describes the 

 careful method which he adopted in order to determine the amount of 



