iz THE POPULAR SCIENCE MONTHLY 



THE FUNDAMENTAL PROBLEMS OF PHYSIOLOGICxiL 



CHEMISTRY* 



By De. EDMUND DKECHSEL, 



PEOFESSOB OF MEDICINE AT LEIPSIC. 



WHEN the science which endeavors to determine the phenom- 

 ena of life and their connection was enabled to employ more 

 exact expedients for its observations, the influence which the chemical 

 process exerts on that of life became known. The physical apparatus 

 of the body are preserved in the aggregate state and form, which are 

 necessary for the performance of their functions by a definite chemical 

 composition of the organs and the fluids which saturate them ; and 

 the source of the power required by the living body for its move- 

 ments is to be sought for in the destruction of the compounds of 

 which it is composed. This statement is not only justified by the 

 axioms of science, but it is also confirmed by experience. For, even 

 where the best methods of chemistry are deficient, we meet with 

 phenomena, the appearance of which can only be explained by chem- 

 ical decomposition. The substances of which the muscle is formed 

 and the manner in which they are arranged are still imperfectly 

 known ; of the chemical process which takes place in the sarcous 

 elements, when a muscle passes from rest to the contracted state, we 

 know scarcely anything ; still, we can not doubt for a moment that 

 the muscle owes its form to its composition, and its motion to a change 

 of the latter. This is shown by the fact that even by a slight change, 

 which we may produce in the chemical constitution, though it be only 

 a change in the amount of water or salt in the muscle, its elasticity, 

 its sensibility, its ability to raise weights, is affected. By comparing 

 the composition of the muscle, recovered after long repose, with that 

 of the muscle tired by exertion, we immediately see that a change has 

 taken place in it. The same may be said of the nerve, which has 

 hitherto offered almost insurmountable obstacles to chemical examina- 

 tion ; for how can its tiring be explained except by a chemical change 

 of its mass? All doubt must here be removed on considering the 

 electric change which accompanies every excitation of the nerve, for 

 the differences in the electric tension, which apjtear in this momentary 

 phenomenon, give distinct evidence of a chemical change. 



For a complete understanding of these phenomena, an exact knowl- 

 edge of the chemical processes in the organism is essential. At pres- 

 ent we do not possess this ; nevertheless, it is well worth the trouble 

 to examine how far we have advanced in this direction ; what require- 

 ments are to be fulfilled for further investigations ; and in what man- 



* Translated for " The Popular Science Monthly" by William Rupp, F. C. S. 



