508 On the Component Parts of Iron-Jloms. 



for the incvcafe of weight, by aflerting that the earthy 

 parts are burnt out and nearly confumed, and that the 

 metallic parts only remain, deftroyed however in their 

 nature and reduced to a cinder. 



We are not to wonder, therefore, at the uncertain refult? 

 which the. untutored manufacturer obtains; until fuch time 

 as along courfe of experience has taught him, that, by com- 

 bining certain caufes, good or bad effects are the confe- 

 quence. Even at laft he ftill rcfts upon an unviable bafis : 

 defiitute of the correct operation of principle, and incapable 

 of preventing an evil from a total ignorance of its real 

 fource of action, he can only in the end avoid it after a 

 feiiltipKcity of movements, wherein he finds his practical 

 knowledge increafed at the expence of a cbnfiderable facri- 

 ficeof property. 



How much more enlightened would be the mind of the 

 manufacturer, were he to attend minutely to the phenomena" 

 developed in all the ftages of his procefs, and fatisfy himfelf 

 as to the radical principles of action in each individual ftage ! 

 In doing this, chemical minutenefs, the terror and butt of 

 the unphilofophifed mind, is not abfolutely indilpenfible ; 

 and yet everything mav be afecrtained neceifary to be known 

 for the production of certain determinate qualities of crude 

 iron. 



He would then eafily comprehend that all iron-ftoncn 

 contain lefs or more water of cryftallifation, and that, being 

 combined with a certain proportion of lime neutralised 

 with carbonic acid, it is necerTary that they be expofed to a 

 heat fufficient to expel the firft and laft of thefe as well as 

 fulphur. Tie reafon has already been given, and the con- 

 fequence fhall be once more ftated. The evil effects produced 

 by introducing raw iron-ftones into the blaft-furnace, are lefs 

 owing to the fmall portion of fulphur contained in molt of 

 them, efpecially in balls, (the vapours of which arife even 

 from the fofteft crude iron when fluid,) than to the de- 

 composition of water and acids., each of which gives up 



a pro- 



