MEASURE OF HEAT IN THE COMBUSTION OF CARBON. 491 



primary result. Moreover, if it can be discovered how much 

 carbonic acid has been produced in a given time, we can pro- 

 nounce how much heat has been extricated, because we know, 

 when a certain quantity of carbon has burned in oxygen, how 

 many times a corresponding weight of water will be thereby 

 raised in temperature one degree of Fahrenheit or one degree 



proportion as the labour is increased, there must be a correspond- 

 ing, increase in the proportion of nitrogenised aliment, otherwise 

 the animal falls out of condition. 



But to come to Professor Frankland's memoir, published while 

 this work was already going through the press, there is no reason 

 to doubt the accuracy of his experiments in the total combustion 

 of muscle, albumen, and urea in pure oxygen gas out of the body, 

 and of the numbers he has assigned to the corresponding units of 

 heat in these several substances. But his conclusions involve two 

 disputed questions, and yet settle neither, unless with assumptions 

 that cannot be admitted without new proofs. The first question 

 is, AYhether or not the mechanical energy of the muscular system 

 is dependent on the disintegration of the tissue of the muscles 

 concerned, and is altogether independent of the mode in which the 

 nitrogen of the fibres, assumed to be decomposed, escapes from the 

 body ] The second question is, Whether the proportion of nitro- 

 gen found in the azotised urinary compounds corresponds, under 

 such limitations as extraordinary conditions must produce, with 

 the supposition that there is in operation so constant a source of 

 the extrication of nitrogen as ordinary muscular exertion in the 

 exercise of the assimilative and relative functions 1 Professor 

 Frankland denies the possibility of muscular energy being depend- 

 ent on disintegration of the contractile tissue and why ? Because 

 he thinks he knows the narrow limits within which nitrogen must 

 be thrown off by the living system. Yet such narrow limits he does 

 not learn from his own experiments, but from the experiment of 

 Fick and Wislicenus, the fidelity of which his experiments were 

 designed to confirm. Is this not the same as reasoning in a circle ? 

 The fidelity of the experiment made by the two Swiss physiolo- 

 gists is assumed in the premises from which Frankland infers that 



