Part

 1 I  |             presence in the laws of heat.~The possibility that it
 2 I  |      experiments on the relation of heat to mechanical force, which
 3 II |     produced in gases by the aid of heat, on a far greater scale.~
 4 II |         steam by the application of heat. But steam, so long as it
 5 II |   interested in the manner in which heat produces elastic vapour,
 6 II |         engines.~We see, then, that heat can produce mechanical power;
 7 II |       performed. How is it now with Heat in this respect?~This question
 8 II |             of Mechanical Theory of Heat.~The older view of the nature
 9 II |         older view of the nature of heat was that it is a substance,
10 II |          processes, the quantity of heat which can be demonstrated
11 II |         bodies; but the quantity of heat which the former lose can
12 II |            gaseous states, in which heat disappeared - at any rate,
13 II |        exactly the same quantity of heat reappeared which formerly
14 II |           seemed to have been lost. Heat was said to have become
15 II |    containing a certain quantity of heat bound, which, just because
16 II |             far greater quantity of heat thus bound. But if the vapour
17 II |          exactly the same amount of heat is liberated as had become
18 II | vaporisation of the water.~Finally, heat is sometimes produced and
19 II |       constant quantities of latent heat, which, when they change
20 II |          shown that the quantity of heat which is developed by a
21 II |          the basis of the theory of heat, that heat is a substance
22 II |            the theory of heat, that heat is a substance entirely
23 II |          with the hypothesis - that heat is a substance. On the other
24 II |    invariability in the quantity of heat in all these processes could
25 II |           no other manner than that heat is a substance.~But one
26 II |      substance.~But one relation of heat - namely, that to mechanical
27 II |            to deduce the work which heat performs, by assuming that
28 II |           law as to the capacity of heat for work, which even now,
29 II |         modern mechanical theory of heat, and the practical conclusions
30 II |          rubbed against each other, heat was developed anew, and
31 II |            an appreciable degree of heat; thus, a lucifer match,
32 II |          hands together to feel the heat produced by friction, and
33 II |          might here liberate latent heat, which would thus appear
34 II |          which would thus appear as heat of friction.~But heat can
35 II |            as heat of friction.~But heat can also be produced by
36 II |            the liberation of latent heat. The first decisive experiment
37 II |            them to melt. The latent heat which the newly formed water
38 II |           been created by friction.~Heat can also be produced by
39 II |   mechanical work is destroyed, and heat produced in its place.~~
40 III|          determined the quantity of heat which is thereby produced,
41 III|          experiments show that when heat is produced by the consumption
42 III|           to produce that amount of heat which is known to physicists
43 III|           physicists as the unit of heat; the heat, that is to say,
44 III|            as the unit of heat; the heat, that is to say, which is
45 III|          the same relations between heat and work were also found
46 III|           when work was produced by heat. In order to execute this
47 III|         produced at the cost of its heat. Hence the cooling, If,
48 III|          the gaseous mass.~How much heat the various gases disengage
49 III|            or, conversely, how much heat disappears when they expand
50 III|        determine the equivalence of heat and mechanical work in friction,
51 III|         then: a certain quantity of heat may be changed into a definite
52 III|          also be retransformed into heat, and, indeed, into exactly
53 III|        exactly the same quantity of heat as that from which it originated;
54 III|             are exactly equivalent. Heat is a new form in which a
55 III|          longer permit us to regard heat as a substance, for its
56 III|             conclude from this that heat itself is a motion, an internal
57 III|            the constant quantity of heat is nothing more than the
58 III|       motive power of the motion of heat, which remains constant
59 III|             engine produce; for the heat which is consumed in the
60 III|            remains as the motion of heat. The same result we must
61 III|           that is, in the motion of heat. And this is so. A pound
62 III|        carbonic acid, gives as much heat as is necessary to raise
63 III|           also the same quantity of heat is produced by the combustion
64 III|             has afterwards imparted heat to the vicinity, we have
65 III|            no longer produce either heat or work any more than a
66 III|            considerable quantity of heat is produced; for a given
67 III|        hydrogen, four times as much heat as in the combustion of
68 III|        which appears in the form of heat. In the water which has
69 III|       producing large quantities of heat by a fresh combination with
70 III|          currents pass they produce heat; I stretch a thin platinum
71 III|            currents are produced by heat in what are called thermo-electric
72 III|          doing so it comes to rest. Heat can perform work; it is
73 III|            or mechanical forces, or heat.~We may express this generally.
74 III|       acquired velocity or produced heat. We might also drive a magneto-electrical
75 III|           into play, produce either heat or electrical currents or
76 III|             work.~We have seen that heat may be changed into work;
77 III|        currents are produced by it. Heat can directly separate chemical
78 III|           the equivalent in work of heat may be found. The equivalent
79 III|            is again measured by the heat which they produce. By similar
80 III|           an equivalent quantity of heat, or, instead of this, of
81 III|        force; and, conversely, when heat is lost, we gain an equivalent
82 III|        disappears, an equivalent of heat or work; so that in all
83 III|             is not possible even if heat, chemical forces, electricity,
84 IV |           be effected by the aid of heat, and this heat comes from
85 IV |           the aid of heat, and this heat comes from the sun. The