12 HlSrORT of the SOCIETr. 



The cylinder being then placed in a HefTian crucible, and fur- 

 rounded with a mixture of dry fand and clay, was fubjecfted to 

 the fire of a fmith's forge for an hour. When taken out, the 

 pyrometer indicated 151 ° ; the vy5.per. part of the iron appeared 

 to have been melted, and feveral bright metallic globides were 

 feen adhering to the compadled mafs of fand and clay next the 

 iron. The lower part of the cylinder retained its fliape, but 

 was blifteredon the furface, except at the bottom, which remain- 

 ed fmooth. When the ends were polilhed and touched with 

 diluted nitric acid, they exhibited the fpot charaderiftic of (Icel, 

 that on the end which had been fufed being confiderably* dark- 

 er than the other. The part which had remained fmooth after 

 being cut oflF, was heated red hot, and plunged into cold water, 

 ■when it became fo hard, that it received no impreffion from a 

 file. Several cavities were found within the, c,j;Undej-,. but the 

 diamonds had totally difappeared. !r''r.-: 



The whole cylinder of foft iron was thus converted into 

 fleel ; one end of it having been melted, was in the flate of cafl: 

 fteel ; the other end, having remained folid, was of t%_kind of 

 fteel produced by cemeiiitation. •■^, , ., 



.'i-^ A G£NTCE>MAN-.eif the Clyderlron^var^s hayinjg;_;abQut^ that 

 time been led> by fome experiments, to doubt of the; conclufive- 

 nefs of thofe made by Guyton, arid to fufpecl that the dia- 

 mond had contributed nothing to the converfion : of the iron 

 into fteel, Sir George Mackenzie thought it, neceflary to 

 diredl fome exjieriments to the folution of this queftion. 



In one of thefe a piece, of foft iron, in all refpeds fmiilar,to 

 that ufed in the laft experiment, was expofed to the fame degree 

 of heat as in that expe;riment, and with all the circumftances 

 alikci except that the diarnonds were, wanting. iTJUe refult was, 

 -that the. iron was not altered ;in its fhape or qualities., It had 

 been expofed'to theheat.*© b9Uf^,^»4 .t4e..pyi]oni?tei;'.. 9iarke4 

 • ■ :» ' '-'■■/;■■ '•, ', -jjiaq 07/J 'jii; .bjiitjqc fc.^5'^ .° 



