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



may nevertheless be obtained. As measurable external labour 

 we chose the ascent of a mountain-peak, the height of which 

 was known. We preferred the mountain to a treadmill, not 

 merely because the ascent is a more entertaining employment, 

 but chiefly for the reason that we had no suitable treadmill at our 

 disposition. Of the numerous peaks of the Swiss Alps, the one 

 most suitable for our purpose appeared to be the Faulhorn, near 

 the lake of Brienz, in the Bernese Oberland. It was necessary 

 that the mountain which was to serve for our experiment should 

 be as high as possible, and nevertheless should permit of our 

 passing a night on its summit under tolerably normal circum- 

 stances ; for had we been obliged immediately to descend again, 

 the measurable amount of work would have been at once fol- 

 lowed by an undeterminable but violent exertion of the mus- 

 cles, in which much metamorphosis would occur, the thermic 

 equivalent of which would be, however, entirely liberated as 

 heat. The Faulhorn satisfies all these requirements; for al- 

 though its height is very considerable, rising to about 2000 

 metres above the lake of Brienz, yet there is an hotel on its 

 summit. Besides, it can be ascended by a very steep path, which 

 was, of course, favourable for our experiment, because the amount 

 of muscular action which is lost and not calculable (being recon- 

 verted into heat) is thus reduced to a minimum. We chose the 

 steepest of the practicable paths; it starts from a little village on 

 the lake of Brienz called Iseltwald, and at a moderate pace the 

 summit may be reached in less than six hours. 



In order to diminish as far as possible the unnecessary con- 

 sumption (Luocusconsumtion) of albumen during our experiment, 

 we took no albuminoid food from midday on August 29 until 

 7 o'clock in the evening of August 30. During these thirty-one 

 hours we had nothing in the way of solid food except starch, fat, 

 and sugar. The two former, following F. Ranke's directions, 

 were taken in the form of small cakes. Starch was rubbed up 

 with water, and the thin paste thereby produced was fried with 

 plenty of fat. The sugar was taken dissolved in tea. There was 

 also the sugar contained in the beer and wine, which were taken in 

 the quantity usual on foot tours. 



The experiment proper began on the evening of the 29th of 

 August, at a quarter past 6 p.m., by a complete evacuation of the 

 bladder. The urine from this time till 10 minutes past 5 on the 

 morning of the 30th was collected and measured; we will call 

 it night urine ; we took a specimen of it with us for examination. 

 Then the urine secreted in the time between 10 minutes past 5 

 in the morning and 20 minutes past 1 in the afternoon of the 

 30th of August was also measured. During this time the ascent 

 of the mountain was performed, it may therefore be designated 



