200 
Iron. 
fects entailed are in the ratio of its combination with the 
iron. From a review of the facts adduced on this subject 
in various parts of my papers, its agency and effects will 
easily be credited by men of science ; its ^property of 
constituting the acidifying base of all the acids readily ex- 
plains the unalienable consequence of its presence with 
acidifiable bases. The effects are still more pernicious 
when the oxygen is furnished by the decomposition of 
water in raw iron-stone ; the hydrogen in this case set free, 
also seizes a portion of the carbon ; and these abstractions, 
united to that produced by the native portion of oxy- 
gen in the stone, form an aggregate which frequently re- 
duces the value of iron 40 per cent . So long as the prin- 
cinciples of science are overlooked in the manipulations of 
the foundry and forge, the existence of such agents will 
be treated as chimeras of the philosopher and chemist, ,1 
and the effects hourly produced by them, industriously at- 
tributed to causes, which in point of unity or consistency, 
will not bear the slightest touch of investigation. 
Of the Iron produced from the blast furnace . I have 
already touched upon this in the preceding paragraphs, 
but the subject is worth pursuing. 
“ The great object of the manufacturer is, with a given i 
quantity of fuel to obtain as large an amount as possible 
of highly carburetted cast iron, as this is the kind which i 
bears the highest price in the market : but as from various 
causes the iron is generally found to be more or less de- 
carburetted, it becomes a matter of considerable impor- 
tance to ascertain by external characters the principal 
changes induced by a progressive diminution of carbon, in 
order that the value of any particular sample may be cor- 
rectly and expeditiously ascertained. By long and care- 
ful observation, it has been found sufficient for all practical 
