ee ee ee ore 
General Reflections on Heai. 91. 
sent is a bright reality. But whence does steam derive this 
power? What renders its force so omnipotent, that, asin Per- 
kins’s engine, a bubble can lift a ship over the waves! ? Lan. 
swer, itis HEAT 
IV. Over the laws of CHEMICAL ARFINITY, the same agent 
exerts a powerful control. If we attentively consider the séate, 
in which all bodies are found, whether solid, liquid, . ol, BI ly, 
form, whichever of these forms the body is in at any, su 
moment, depends on the quantity of heat that happens to. 
combined with it. . Were it not for this agent, HP povice 
we could suppose them to exist without it, would be in the. 
state of solids, Water and all liquids, air and all gases, are 
maintained in their Feapsciing states by its influence alone. 
In the nepdonon: of all chemical phenomena, indeed, no 
agent.is of so frequent recurrence. as this, Some nts, 
we unite into a. compound. by heat; some. Pap ae 
resolve, by the same means, into their elements. 
to this dominion which heat exerts oyer chemical Lb Sade! 
it becomes the chief resort.and dependence. in so many. 
pepnennes of the arts, both the usefyl and the ps Eats 
he greater number of. the arts, indeed, are so entirely der . 
pendent on this power, that they can advance hardly a step — 
without.it. Iron, from its intimate relation, and indispensa- 
ble utility in all the mechanical operations, has. been. propstik 
denominated ‘the soul of the arts;’ but if we go one step. 
further, we shall find that i iron pital’ is opt, ane, epuld not. be, 
touhioh.is is afterwards — 
over it to bring it to the metallic state! ‘These are Fiewonen' 
to convert it into steel. By heat it is manufactured into those. 
numberless forms that every where meet our eyes. Fourcroy 
sums up the uses of fire in the following comprehensive sen- 
pty  Itis with fire,” says he, “that man prepares his food, 
he dissolves metals, vitrifies rocks, hardens clay, sof 
on and gives to all the productions of the earth, the forms 
and combinations which his necessities require.” 
Y. But our attention has been hitherto engrossed with cons, 
templating the agencies of heat on the unorganized forms of 
