Conservation and Innovation : Helmholtz's Struggle with Energy ...

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The amount of animal heat predicted by Liebig was in fact smaller then the one measured by Piere Louis Dulong and Cesar-Mansuète Despretz. Thus the difference might have been explained through the effect of vital forces. Helmholtz wanted to eliminate the discrepancy between theoretical predictions (Liebig) and experimental results (Dulong and Despretz) in order to eliminate any role for the vital forces. He tried to achieve that through a theoretical reformulation of the terms of both sides of the equation relating the heat ingested with the one emitted by living bodies. Helmholtz proposed first that the heat of the "Ingesta" be considered no more as the one resulting from the oxidation of the elements of the food, but instead as the one resulting from the oxidation of the compound themselves of the food. The last one was supposed to be greater. Second Helmholtz proposed that the heat developed in the animals be considered not only as the one produced in the respiratory organs 40, but that also the heat produced in the blood and tissues should be taken in account 41. With this new elements, according to Helmholtz, theoretical predictions would satisfy experimental data and the acceptance of the new model of heat would leave no room for the vital forces. Still the experimental corroborations were highly problematic 42. I want to note that the mechanical equivalent of heat was discussed 43, even if a determination of the equivalent itself was lacking and thus a component was lacking in the theoretical energy balance put forward, namely the work done by the animals 44. Thus in my view Kuhn's assertion that in1845-6 "Helmholtz fails to notice that body heat may be expended in mechanical work" 45 requires qualifications: it does not imply that "Helmholtz's conservation ideas were not complete till 1847". In fact, already in his "Muskelaction", Helmholtz asserted that the problem was "whether or not the mechanical force and the heat produced in an organism could result entirely from its own metabolism" 46 and in n.148 p.248. 40 For Kremer this does not correspond to Liebig's conception: "Therm. of Life" 41 Lenoir Strat of Life P.204 42 Kremer: "Therm of Life" P.251 43 Helmholtz: WA 2 Pp.699-700. 44 Kremer asserts that Helmholtz never succeeded in bringing heat and work operationally together into physiological research: Kremer "Therm of Life" P.238. 45 Kuhn Sim Disc p.95 n 68. 46 see above n.36.
his "Wärme" that one of the differences between the kinetic and the caloric theory of heat is "the determination of the equivalent of the heat that can be produced through a given quantity of a mechanical or electric force" 47. A more detailed discussion, as shown below, is in the "Bericht". It is true that Helmholtz did not provide in the first papers a mechanical equivalent of heat, but not for the lack of adequate conceptualization. He lacked experimental reliable data, a problem still present in the Erhaltung . Helmholtz himself, in the last section of the Erhaltung , explained that given that the amount of work produced by animals compared to the heat is small 48, it can be neglected and the problem of conservation of force in physiology is reduced to the problem whether the combustion and the transposition of food can produce the same amount of heat produced by the animals. Helmholtz added that the results of his own work in the "Wärme" and the "Bericht", compared with Dulong and Despretz's measurements, allowed a positive answer, at least approximately. Thus Kuhn's remarks, prompted by his desire to stress presumed influences of Natürphilosophie on Helmholtz, seem dubious. Even contradictory if compared with his other remarks 49, written to deny that Helmholtz had been influenced by the concepts of conservation present in the tradition of analytical mechanics, that Helmholtz's conservation ideas pre-existed his 1842 reading of D.Bernoulli. A great step forward in the elaboration of the methodological strategy was achieved in October 1846 50 in the first "Bericht" written for the Fortschritte, where it was published in 1847. The word "methodological" must be stressed because despite Koenigsberger's assertion 51 that Helmholtz at the time was involved in detailed experimentations, no new experimental result whatever is in this paper. The relevant feature is the extension of the correlation principle from physiology to various branches of physics and chemistry and thus this was Helmholtz's first attempt at a general application of his methodology. Without 47 Helmholtz "Wärme" WA2 Pp.699-700. 48 See also the views expressed in the "Wärme" quoted in Olesko & Holmes "Experiment" Pp.21-2 n.70.: "(animal heat) is by far the greatest part of the Kraftequivalent". 49 Kuhn Sim Disc p.97 n.76. 50 Koenigsberger H v H P.34. 51 ibidem pp.34-5.
Page 1 and 2: Fabio Bevilacqua Conservation and I
Page 3 and 4: different formulations 4 and priori
Page 5 and 6: and interesting results, despite th
Page 7 and 8: principle of correlation is express
Page 9 and 10: principle to the existing empirical
Page 11 and 12: the origin and meaning of the princ
Page 13 and 14: Whether physiological research, apa
Page 15: In a discussion on the origins of a
Page 19 and 20: generate a determined equivalent of
Page 21 and 22: "Bericht", despite the application
Page 23 and 24: experiments in the most disparate b
Page 25 and 26: The premise reveals that the struct
Page 27 and 28: intelligible if it can be referred
Page 29 and 30: elevant consequence of the deductio
Page 31 and 32: Needless to say the plan was to be
Page 33 and 34: and from here that the direction an
Page 35 and 36: since Leonardo 113; the "ad nihilum
Page 37 and 38: But unfortunately for the whole str
Page 39 and 40: The principle of conservation of vi
Page 41 and 42: different from the one joining the
Page 43 and 44: "The equality that exists between e
Page 45 and 46: In virtue of its limitations to New
Page 47 and 48: Helmholtz, while asserting that lig
Page 49 and 50: the temperature of 1 Kg of water ca
Page 51 and 52: In his search for a mechanical equi
Page 53 and 54: had already been achieved in the Be
Page 55 and 56: approach is discussed at length and
Page 57 and 58: and unaware of Green's results190,
Page 59 and 60: potential function 201. It is worth
Page 61 and 62: and judged unreliable, despite prov
Page 63 and 64: The relevance of the first question
Page 65 and 66: principle taking this potential int
Page 67 and 68:
Finally we get to the real conclusi
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conservation 234, on the theory of
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for the mechanical equivalent of he
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The controversy started with some r
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where μ are immovable masses, m th
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demonstration criticised by Clausiu
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directions that join them and whose
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quotes 288 and criticises a proposi
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motion to all natural forces, the k
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measure this expenditure and compar
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" ...the quantity of force in natur
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forces is constant: but it relates
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experiences in general laws of unli
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"a series of important and difficul
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the Discontinuous Movements of Flui
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methodology. Dühring claimed the c
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The first history of the conservati
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while in Britain for the above talk
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apply it to acoustics (1859), hydro
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magnetic intensity. Maxwell realize
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and the electrostatic In modern not
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of conservation of energy: it is re
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efuted. But again in 1881 Helmholtz
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But was important here is that desp
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The second (1892-94), follows the i
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while the electromagnetic and the s
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can modify its specific theoric for
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considered relevant. In Poincarè
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meaning left is: "There is somethin
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interpretations at the beginning of
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while fighting metaphisicians, he w
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literature 456. There is an intrins
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assertion is surprising: it has lon
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Kant was a Naturphilosophe 480. The
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condition that work done by the for
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histories cites these (Hirn's) arti
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) the experimental determinations o
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force principle 522. Elkana tried t
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Blüh, Otto. "The Value of Inspirat
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Graetz, L. "Das Mechanische Wärme
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Helmholtz, Hermann. "Bericht über
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Helmholtz, Hermann. Wissenschaftlic
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Madison: Wisconsin U.P., 1959. Pp.
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Poincarè, Henry. Electricité et O
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Yagi, Eri."Clausius's Mathematical
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