On Metallic Minerals. 407 



told that there are only three places iti Eiiefland, in which 

 it iiiis been found, viz. Highijatc, Woohvich and Liverpool, 

 from the last of wliich places it is obtained for the moulding 

 rooms in Scotland. 



The following' characters appear to be necessary to con- 

 stitute a good moulding sand, viz : — 



1st. — Great fineness in the particles. 



2d. — A freedom from any which soil the fingers. 



3d. — Infusibility and incombustibility at the temperature 

 of melted iron. 



4th. — Sufficient adhesiveness to prevent the liqiiid iron 

 from washing any of the particles away. 



.Oth. — Forosity to allow thecsca|»e of the gas, (hydrogen,) 

 which is generated when the fused metal decomposes the 

 slight degree of moisture necessarily present in the sand, 

 and which gas is observed to burn away with a blue flame 

 on the surface of the mould. A mixture of silex and 

 alumine, the former predominating, and both in a state of 

 considerable fineness, would afford an article which, 

 judging « priori, would be likely to answer. Tiie preseiise 

 of the red or yellow oxide of iron in an ochrey state would 

 not probably injure its qualities, but all sand containing 

 carbonate of lime or vegetable substances should be rejected, 

 as the former, when in contact with thell(piid metal, would 

 act as a flux upon the other minerals, while the latter 

 would burn away, leaving vacuities, both of which circum- 

 stances would injure the impression ; much of this, it must 

 be confes'-cd, is conjecture, unsupported l)y any experiment 

 with which I am ac(piainted. 



At Three Rivers there is a small establishment for 

 recasting old iron and pigs brought from the forges of St. 

 Maurice, which the occurrence of the Sabbath prevented 



3 I- 



