Origin of Muscular Power. 495 



of protein substances appeared in the urine as the surplus 

 which might possibly have been retained after work, over and 

 above that normally contained in the tissues. This being 

 granted, we have the data for further calculations, in the total 

 amount of nitrogen contained in the work urine and after- work 

 urine (see page 492). This is for Fick 38*28 grms., and for 

 Wislicenus 37*00 grms. of decomposed albumen. To the first 

 of these two figures we may apply a slight correction. For ob- 

 vious reasons, we were compelled to measure the night urine 

 at our hotel at Interlaken at ]0 minutes past 5. But the 

 work really began two hours later, after one hour passed on the 

 steamboat, and another spent over breakfast at Iseltwald ; there- 

 fore the urine secreted during these two hours ought not properly 

 to have been reckoned with the work urine. In the case of 

 one of us, however (Fick), this error may be in some measure 

 repaired ; just before the ascent he had discharged a quantity of 

 urine into the vessel destined to receive the work urine. This 

 quantity could not indeed be measured, because the graduated 

 apparatus had been packed up at Interlaken, but, by the eye, it 

 must have been at least as much as 20 cubic centims. If we 

 assume that this quantity of urine contained the same propor- 

 tion of nitrogen as the work urine, it would correspond to 

 I'll grm. of albumen, which we ought without doubt to deduct 

 from the number 38*28. We thus obtain for the greatest pos- 

 sible quantity of albumen oxidized in Fick's body during the 

 ascent 37*17 grms. 



The question now arises, what quantity of heat is generated 

 when 37*17 and 37*00 grms. of albumen are respectively burnt 

 to the products in which their constituent elements leave the 

 human body through the lungs and kidneys ? At present, unfor- 

 tunately, there are not the experimental data required to give an 

 accurate answer to this important question ; for neither the heat 

 of combustion of albumen nor of the nitrogenous residue of 

 albumen is known. We are able, however, to assign a limit 

 which the quantity of heat in question will not overstep. In 

 fact it is quite certain that the amount of heat which 1 grm. of 

 albumen will give when completely burnt must be less than the 

 amount of heat which would be obtained if the combustible ele- 

 ments contained in a gramme of albumen were burnt separately ; 

 that is, in other words, the heat of combustion of albumen is 

 less than that of a mixture of the elements in the same propor- 

 tions, and not in combination with oxygen. Now the latter 

 number may be easily calculated; it is only requisite to de- 

 termine how much heat would be produced by the combus- 

 tion of the amount of carbon and hydrogen contained in a 

 gramme of albumen. The nitrogen may be neglected, since it is 



