106 THE SECRETIONS: 



of solution in the blood, (see vol. I, p. 135,) it may readily be 

 conceived that they will exhale at those points where the blood 

 in its passage through the capillaries comes in the most inti- 

 mate contact with the external atmosphere ; at least it seems a 

 simpler view to regard it as a mere physical process than as a 

 disintegration of animal matter by the secreting organs. In 

 fact, the cutaneous exhalation must be regarded, as Edwards 

 has observed, in the light of a partly physical, partly organic 

 process. The product of physical exhalation is pure water and 

 gas ; the product of organic exhalation contains animal consti- 

 tuents, which must be regarded as secretions of cells. 



The amount of exhaled matter is liable to great variations : it 

 is increased by a dry and light atmosphere ; and is lessened 

 by a moist, vapoury, dense, and calm atmosphere. During and 

 immediately after meals the exhalation is at its minimum; 

 it attains its maximum during the actual period of digestion. 

 The cutaneous exhalation is in antagonism with the urinary 

 secretion and the pulmonary exhalation, so that an excessive 

 secretion of urine diminishes the action of the skin, and, 

 conversely, the renal functions are less energetic when the skin 

 exhales freely. 



On Morbid Sweat. 



Our knowledge of the chemistry of normal sweat is very im- 

 perfect ; but our information respecting the changes which this 

 secretion undergoes in disease is still more deficient. Our 

 ignorance may be explained, and in some measure excused, by 

 the extreme difficulty of obtaining, in a state of purity and un- 

 adulteration, a sufficient quantity of the secretion for the pur- 

 pose of forming a successful chemical analysis. 



Dr. Piutti, of Elgersburg, has had the kindness to present 

 me with some sweat which he obtained from persons during 

 the use of the water-cure, and also with a manuscript communi- 

 cation containing some analyses of sweat instituted by himself, 

 which I shall at once proceed to enumerate. 



The manner in which he conducted his analyses is not stated. 

 "We observe the absence of salts of lime in these analyses, and 

 Piutti states that he could find no traces of phosphate or ben- 

 zoate of lime, the former of which has indisputably been de- 



