IS 13.] Chemical Properties of Animal Fluids. 415 



great simplicity, ought to be placed among the most important 

 conceptions for the arts, and we propose to the Class to give it 

 its approbation. 



(Signed) Perier, Prony, Carnot, Reporters. 



The Class approves of the Report, and adopts its conclusions. 



De lamb re, Perpetual Secretary. 



Article V. 



General Views of the Composition of Animal Fluids. By J, 

 Berzelius, M.D. Professor of Chemistry in the College of 

 Medicine at Stockholm. 



{Concluded from p. 387.) 



Of the Fluids that compose the Excretions. 



I must refer the reader to what I have already observed gene- 

 rally on this subject, and shall proceed to the individual species. 



1 . The Fluid of Perspiration. 



I have not been able to make my experiments on this fluid in 

 any large quantity, the organ that secretes it being extended 

 over so large a surface, and seldom affording much at a time. 

 As to what collects in under-waistcoats after some days' wearing, 

 it must always be more or less altered by spontaneous decompo- 

 sition. 



1 collected on a watch-glass a few drops of sweat as they fell 

 from my face, and evaporated them carefully. The yellowish 

 residue had all the appearance under the microscope of the usual 

 mixture of the muriates of potash and soda with lactic acid, 

 lactate of soda, and its accompanying animal matter. It red- 

 dened litmus, and dissolved in alcohol, and was without doubt of 

 the same nature as the analogous matter found in the other 

 fluids. The alcohol left untouched a small trace of an animal 

 matter which blackened in the fire, but was in too small quantity 

 to admit of further examination. 



M. Thenard discovers acetous acid in perspiration, but this 

 acetous acid is produced here, as in his other experiments, from 

 the laclic, by his mode of operating. It is well known that 

 litmus paper reddens instantly when put in contact with the skin 

 of the living body; which shows that the acid that produces this 

 effect is not volatile, otherwise it would be evaporated by the dry 

 surface of the bodv, which has always a temperature of Ho to 

 90° Pahr. 



o 



