248 On the Component Parts of Iron-Jlones. 



greater proportion of filex predominated. Though by far 

 the greater number of experiments performed on this fub- 

 ject were in favour of fuch an inference, yet I have at 

 times experienced my arrangement palpably contradicted, 

 without being able to folve the obtruding difficulty. I fhall 

 not however defpair, in moll cafes, to reduce to certain in- 

 variable inherent properties, and external charatteriftic 

 forms, the various iron-ftones in the manner in which I 

 have arranged them, and confonant to the remits obtained 

 From them in the procefs of manufacture. The utility of 

 hich an arrangement, founded upon experiment, mult be 

 ebvious and finking : it will give certainty and value to the 

 various products of the manufacturer, as it will in the end 

 fyftematize the manufacture itfelf, and reduce it to rules 

 guided bv principle, and not by the aberration of a falfe or 

 m i fi n formed j udgment . 



From many experiments I have made with all the varie- 

 ties of iron-ftones found in this country, I {hall rubjoin the 

 treatment of one of each clafs, highly marked with the pre- 

 dominating earths, that an accurate opinion may be formed 

 of the phenomena exhibited in this part of the procefs. 



T. I ufed a fine argillaceous iron-ftone, in fmall pieces, 

 'weighing - - 1750 gr». 



After a proper diilillation of 8 hours in a de- 

 gree of heat equal to 30° of YVedgewood, I ob- 

 tained a fine purple-coloured iibrated iron-ftone, 

 which, when cold, weighed - - - 1160 



Lofs of water, acid, and fulphur, equal to 33 - 6 

 per cent. - 590 grs. 



The influence which the magnet pofletTed over this ftone 

 was coniiderable ; the adhefion to the tongue was however 

 great. 



I next introduced in:o a proper vcffel, in contact with 



charcoalv 



