390 CUTANEOUS SECRETIONS. 



calculation depend for the most part on very uncertain assump- 

 tions, no great weight can be attached to the final result. The 

 argument ex part e in totum here holds good even to a less extent 

 than in any other case, in consequence of the unequal distribution 

 and unequal development of the glands (as, for instance, in the 

 axillary region) ; and finally, the cutaneous surface, when enclosed, 

 can hardly discharge its functions in the same manner as when it 

 communicates freely with the atmosphere. 



The calculations founded on the very laborious investigations 

 of Seguin* should lead us nearer to the truth, although the non- 

 volatile constituents of the skin have not been here included in 

 the calculation. Seguin obtained absolute numbers for the amount 

 of matter transpired by the skin, by weighing his body in such a 

 manner that he determined the loss of weight which the body 

 experienced when the respiration and perspiration are unimpeded, 

 and then compared this with the loss of weight which the body 

 underwent when the perspiration was retained in an air-tight case. 

 It appears from these experiments, that the mean amount of the 

 cutaneous is to that of the pulmonary transudation as 2 : 1, a 

 ratio to which the still more carefully conducted experiments of 

 Valentin also lead us, if we deduce it, as Krausef has done, from 

 the sum of the quantities of water and carbonic acid expired by 

 the lungs in twenty-four hours, and from the loss of weight which 

 occurs during the same period from pulmonary and cutaneous 

 transpiration. Valentin J found, by weighing at intervals of three 

 days, that on an average his body lost 1246*93 grammes in twenty- 

 four hours from cutaneous and pulmonary transpiration ; from his 

 measu rings of the quantities of water and carbonic acid that are 

 expired, as contrasted with the quantity of inspired oxygen, it 

 followed that in the same time Valentin lost on an average 455*18 

 grammes ; hence the perspiration in twenty-four hours amounted 

 to 791*75 grammes, and the ratio of the perspired to the expired 

 matters was as 9:5. Notwithstanding that the calculations 

 founded on his experiments led to almost the same results as those 

 of Seguin, Valentin regards it as altogether impossible that more 

 matters should be eliminated by the cutaneous perspiration than 

 by the pulmonary exhalation ; I agree, however, with Krause, 

 in thinking that the above ratio is in all probability the true one. 



* Ann. de Chira. T. 90, p. 52 88 et 413580. 

 t Op. cit., p. 144. 



Lehrb. d. Physiol/d. Menschen. Bd. 1, S. 714. 

 Ibid., p. 582. 



