rz - Striétures on Mr. Collier's : 
ing hard when plunged into cold water. This alone gives. 
it an almoft entire maftery over all other metals and fub- 
flances; it conftitutes its folidity, durability, and polith ; 
in fhort, all its utility, whea manufactured into the many 
various inftruments of ufe, is derived from this unrivalled 
peculiarity of the metal. 
It is impoffible to difcover what could have led Mr. C, 
in attempting an explanation of the ule of “ plunging 
into water,” to fay, that it is done to prevent the fteel 
<¢ returning tothe ftate of malleable iron :” the fallacy of 
this affertion muft be obvious to the Jeaft mtelligent work- 
man. Plunging and heating alternately are the fpeedieft 
methods for bringing fteel back to malleability: the 
Scldomer it is plunged or heated, the longer it will preferve 
the carbonic principle, and confequently remain good. 
Has Mr. C. been told that at fieel manufactories, where 
bar ftcel is drawn into fhapes, and bars of various. dimen- 
fions, that all thefe are immerfed in water, left they fhould, 
af left without this precaution to cool in the open air, be- 
come malleable iron? Were this the cafe, fteel could never 
be fubjected to the file--nor could files be ftruack—becaufe 
fteel could not then exift unlefs in a hardened ftate. Let 
me afk Mr. Collier, whether, at thofe manufaétories of fteel 
which he has frequented, the trial bars taken from the 
aperture of the furnace were found, when cold, in the ftate 
of malleable iron, or otherwife ? 
The note at the bottom of page 47 is extremely vague, 
Can there be an expreffion more indefinite, than that ‘a 
partial abftraction of oxygen takes place by plunging hot 
metal into cold water?”? From what is the oxygen ab- 
{tracted ?. Is it from the hot metal, or is it the oxygen of 
the decompofed water? If from the former, pray what ftate 
of the metal does Mr. C. allude to? Pure fteel contains na 
oxygen; malleable iron, properly manufactured, is alfo yoid 
of the bafe of vital air: crude iron alone contains oxygen, 
an additional quantity of which it abforbs, when dropt fluid 
7 inte 
