tvith various Kinds of Glafs, 155 



It would appear from thefe experiments with bottle glafs 

 and Britifli cold-fhort iron, that a quality of eaft malleable 

 iron is obtained, different, in general, from the produfts ob- 

 tained with Swedifli iron ; that the leafl dutSlile iron is formed 

 when equal portions of glafs and iron are ufed ; and, that the 

 nioft du6tile ftate refults from fullng the iTon ptrjl; 



It cannot, however, be inferred from this, that the general 

 want of dudility is owing to a combination of glafs with the 

 iron, feeing that when Swedifh iron was employed under 

 fimilar circumdanceiJ no want of duftility was perceptible ; 

 I would rather infer, that the difference betwixt the fufed re- 

 fults was charafteriftic both of the fpecies of the iron iand the 

 nature of the manufafture. 



The following experiments were performed with flint and 

 window glafs, to prove whether any part of the difference, in 

 point of quality, arofe from the nature of the glafs ufed. 



Grains. 



Exp. XV. Britifli cold-fhort iron - 875 



Flint glafs - 875 grains. 

 The metallic button refulting from this fufion was 

 denfe and very fmooth (kinned, entirely free from 

 traces of cryftallization. It weighed - - yo^ 



Loft in fufion, equal to — ^th part, 83 



The frafture of the button was compofed of large facets, 

 bright, and inclining to a cubical ftrufture. One-half of the 

 button drew into a loofe {haly bar, confiderably cracked upon 

 the edges. In point of quality it refembled produfts XII 

 and XIV. A button of foft lead was found beneath the iron 



weighing 133 grains, equal to ~ part the weight of the 



g'afs. , . . Grains. 



Exp. XVI, Britifh cold-fliort iron - - 3500 



Flint glafs '-, or 1750 grains. 

 A perfe(ft fufion of this mafs was obtamcd in an hour.' 

 The metallic mafs weighed - - 33^7 



Loft in fufion, equal to — jrth part, 183 



The frafture of this l)utton was a mixture of granulated cryf- 

 tals, and bri'iht laminated facets, fomewhat inclined on edge. 

 The half ortlie button drew into fhape, and formed a bar 

 fomewhat loole and cracked. Upon the whole, the differ- 

 ence betwixt XII, XIV, XV, aiul this, was fcarcely per- 

 N 4 ceptiblc. 



