112 ON THE: PLACE OF FISH LN 
granting also that we know the amount of heat which 
is liberated when a gramme of albumen is changed 
by oxidation into the products of decomposition in 
which the constituents of albumen leave the human 
body ; then if the thermic equivalent of the manual 
labour # be greater than the amount of heat which 
could possibly be produced by the oxidation of p 
grammes of albumen, the question may be negatived 
with the most complete certainty. But if, on the 
contrary, the thermic equivalent of  metre-kilo- 
grammes is less than that of the heat arising from the 
oxidation of # grammes of albumen, the question has 
by no means received an affirmative answer. It is 
only in the former case that the experiment has a 
decisive result. 
Such an experiment has been made by us con- 
jointly. . . . As measurable external labour we chose ” 
the ascent of a mountain peak, the height of which 
was known. . . . 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 moun- 
tain 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 circumstances; for had we been obliged 
immediately to descend again, the measurable amount 
of work would have been at once followed by an 
undeterminable but violent exertion of the muscles, in 
which much metamorphosis would occur, the thermic 
equivalent of which would be, however, entirely libe- 
rated as heat. The Faulhorn satisfies all these re- 
quirements ; for although its height is very consider- 
able, rising to about 3000 métres above the lake of 
