496 Drs. A. Fick and J. Wislicenus on the 



known to be set free in the combustion of albumen. Very pro- 

 bably also nitrogen has no heat of combustion at all ; that is to 

 say, in the combination of an atom of nitrogen with oxygen 

 there is not so much heat developed as is consumed in the se- 

 paration of the molecules of oxygen into the atoms of which 

 they are composed. A gramme of albumen contains 0*535 grm. 

 of carbon, which, computed at the highest rate (8080) for the 

 heat of combustion of carbon, gives 4*32 units of heat. For 

 the combustion of the 0*07 grm. of hydrogen contained in 1 

 grm. of albumen, putting 34,462 for the heat of combustion 

 of this element, there are 2*41 units of heat ; altogether for 

 1 grm. of albumen 6*73 units of heat. The true heat of com- 

 bustion of a gramme of albumen is therefore in any case con- 

 siderably less than this number; and still smaller must the 

 amount of heat be which is liberated by the imperfect oxidation 

 of a gramme of albumen as it actually occurs in the human 

 body. Conceding this point to our opponents, and making the 

 almost absurd assumption that 6*73 units of heat are produced 

 by the consumption of 1 grm. of albumen in the human body; 

 then there would arise from the consumption of albumen, in the 

 case of Fick, 37*17 x 6-73 = 250, and in that of Wislicenus 

 37*00 x 6*73 = 249 units of heat, available for the muscular work 

 done in ascending the mountain. Expressed in units of work, 

 this gives for Fick 106,250, and for Wislicenus 105,825 metre- 

 kilogrammes. 



Let us now inquire how much work was really done by our 

 muscles. One item necessary for the reply is already at hand, 

 viz. the height of the summit of the Faulhorn above the level of 

 the lake of Brienz multiplied by the weight of the body ; the 

 former reckoned in metres, the latter in kilogrammes. The 

 weight of the body with the equipments (hat, clothes, stick) 

 amounted to 66 kilogrammes in Fick's case, and 76 in Wisli- 

 cenus's. The height of the Faulhorn above the level of the 

 lake of Brienz is, according to trigonometric measurements, ex- 

 actly 1956 metres. Therefore Fick performed 129,096 and 

 Wislicenus 148,656 metre-kilogrammes of muscular work. 



The question we put at the outset is in this manner defini- 

 tively answered. The burning of protein substances cannot be 

 the only source of muscular power ; for we have here two cases 

 in which men performed more measurable muscular work than 

 the equivalent of the amount of heat, which, taken at a most ab- 

 surdly high figure, could be calculated to result from the burning 

 of the albumen. But our proof becomes far stronger when 

 we consider that a much greater amount of heat must have been 

 given forth by the force-producing chemical processes than is 

 equivalent to the measurable external work performed. In the 



