of Cast Iron. 23 



informed, that Dr, Wollaston had discovered titanium in the 

 copper-coloured cubical crystals, which are sometimes found 

 in the old furnace hearths at smelting iron works. 



I cannot help feeling it as a matter of considerable reoret, 

 that circmnstances occurred to prevent the publication of my 

 paper on this subject at the time intended, as the attention of 

 Dr. Wollaston and other able men in the scientific world might 

 have been earlier attracted, there' being, amongst the other 

 varieties of crystallized iron sent Mr. Lowry, an elegant speci- 

 men of cubes found in the hearth of a furnace at the Clyde Iron- 

 Works, in the year 1 794, which it was intended to engrave, 

 and of which I have now a rough drawing in my MSS. 



Soon after the discovery of these cubical crystals, I sent a 

 specimen of them to the late Mr. Day, to transmit to the Abbe 

 Haliy, with the view of ascertaining whether this variety of 

 iron was a nevv discovery, or a modification, which might have 

 come under his extensive observation, without having been 

 particularly alluded to in his Crystallography. The Abbe's 

 reply, through the medium of my friend Mr. Day, was, that 

 the specimen was rare (leaving me to infer that he had met 

 with it before), and that he considered it an igneous sulphuret 

 of iron. This answer, from authority so high, tended much 

 to repress further investigation on my part ; and from this cir- 

 cumstance, contrary to some experiments of my own, I was 

 led to rest satisfied with the same conclusion. 



It is with considerable pleasure, however, I learn that 

 Mr. Lowry has carefully preserved the specimens I sent him 

 twenty-three years ago ; and though the silvery pyramids of 

 the cast-iron must have tarnished after so long an interval, 

 yet, judging from the only remaining specimen of the cop- 

 per-coloured cubical crystals, now in my possession, out of 

 forty or fifty pounds originally obtained li-om the furnace- 

 hearth, I hope the specimen sent to be engraved, has pre- 

 served its original variety and beauty of colour. Subjoined 

 is the substance of what I find recorded in my MSS., with re- 

 gard to the discovery of, and some experiments made with, 

 copper- coloured crystals. 



In the year 1 794, I was resident at the Clyde Iron- Works, 

 and in the habit of making observations on most subjects re- 

 lating to iron, and iron furnaces. One of the blast finnaces 

 was thrown out, to receive a new hearth ; in breaking up the 

 old one, a great mass (commonly called the salamander) of co- 

 agulated matter was found upon the surfiice of the old stones, 

 composed of metal, cinder, and coke; upon the uj)per side it 

 was friable, and broke oH" easily, but became harder as it ap- 

 proached the stony material of which the hearth was origi- 



uaTlv 



