416 VOIT. TRAUBE. [BOOK 1. 



Thus the oxidations of the body result in the generation of heat 

 and of motion, which therefore, within limits, are complementary to 

 each other. With a certain chemical combustion, the greater the 

 mechanical effects produced, the less the amount of heat which 

 appears ; and conversely. During the performance of mechanical 

 work a proportion of the heat which would otherwise have been 

 sensible becomes 'latent,' this proportion being equivalent to the 

 work done. 



In this manner J. R. Mayer emancipated muscle from the doctrine 

 of vital force, and taught the true source of muscular power in the 

 chemical union of substances. Muscles, according to him, are an 

 apparatus for the conversion of chemical difference into mechanical 

 effect, just as plants are an apparatus for converting light into 

 chemical difference ; and this power of living muscle is what con- 

 stitutes irritability. At the same time experiment was surely estab- 

 lishing the other opinion which Mayer had, on theoretical grounds, 

 opposed to Liebig's teaching, viz. that muscular exercise is not 

 associated with an extraordinary destruction of the nitrogenous 

 substance of muscle. 



Voit The experiments of Voit * on dogs, which have already 



been described, may be said to have effected the final 

 overthrow of the older views. Voit himself seems to have mistaken 

 the meaning of these experiments. He was compelled to admit that 

 no more nitrogenous waste occurred in muscular exercise than in 

 muscular rest ; but he appears to have taken no account of the well- 

 marked increase of respiratory products in the same circumstances. 

 He drew the conclusion that no more energy is expended during 

 exercise than during rest, but the same energy takes another form ; 

 and as he found no evidence that this transformation was one of heat 

 into mechanical motion, he supposed that it was a conversion of 

 electrical energy. This view was never much encouraged. 



Moritz Traube, on the other hand, who was inves- 

 tigating the subject when Voit published his researches, 

 recognized at once the great importance of the experiments, and 

 explicitly formulated the view that no albuminous body is used up in 

 muscular contraction. On the contrary, muscles contribute rather to 

 the non-nitrogenous respiratory excretions. They are a chief seat 

 of the oxidations of the body, and by means of their nerves the 

 oxidations which occur in them are made to yield mechanical energy. 



_, .. . A still more interesting advance in the theory of 



Matteucci. ,. i i 



muscular contraction concerns the oxygen which serves 



the oxidations of muscle. Already in 1856 Matteucci 2 had remarked 



1 C. Voit, Untersuch. u. den Einftuss des Kochsalzes, etc., auf den Sto/iuechscl. 

 Munchen, 1860. 



2 Ch. Matteucci, ' ' Kecherches sur les phe'nomenes physiques et cbimiques do 

 la contraction musculaire. " Ann. de Chimie et de Physique, 3 e Se'rie, Vol. XLVII., 1856, 

 p, 129. 



