MORE HYDROGEN IN PROTEINE THAN IN UREA. 493 



albuminous ferments secreted for the purposes of digestion into 

 the alimentary canal, such as ptyaline, pepsine, pancreatine, and 

 the intestinal ferment.* A certain amount of water is formed 

 by the oxygen afforded by the blood, as there is more hydrogen 

 in the proteine decomposed than in the urea formed. There is 

 but a small proportion of carbon in urea, and a small propor- 



atoms urea, without reference in the mean time to the nitrogen 

 thrown off as a constituent of other substances. 



As to the experiment made so recently by Tick and Wislicenus, 

 it is impossible not to compliment them on the spirit that led them 

 to undertake the ascent of a lofty mountain for a scientific purpose. 

 Nevertheless they have laid themselves open to criticism on one 

 or two points, that render their conclusions less trustworthy ; first, 

 they have overrated the work done, and next they neglected the 

 precaution so strongly urged by so high an authority as Smith 

 when he showed that the period of the production of urea is not 

 necessarily its period of elimination. To find the work done in 

 terms of the mechanical equivalent of heat, they multiply the 

 weight of each of their bodies, with the addition of the load 

 carried, by the height of the mountain. But the mechanical 

 equivalent of heat founds itself on the lifting of a weight verti- 

 cally, as water is lifted by a bucket and a hand-rope from a draw- 

 well. 



It is at once seen how much greater the task would be to lift the 

 weight of either of these tAvo gentlemen, the one weighing 148 lb., 

 and the other 171 lb., through a height of between six and seven 

 thousand feet, the height of the Faulhorn, than to climb that 

 mountain by a frequented path. Their ascent was necessarily on 

 the hypothenuse of a right-angled triangle, the perpendicular being 

 the vertical height of the mountain. If the general inclination of 

 their ascent was an angle of 45, then the triangle was a right- 

 angled isosceles triangle, so that the perpendicular as well as the 

 base would be more than a third less than the hypothenuse. But 

 the force which raises a body along an inclined plane is to the force 

 necessary to raise the same body vertically, in the inverse ratio of 

 * Playfair, < The Food of Man, in Relation to his Useful Work,' p. 56. 



