Ralph W. Webster 27 



IX. SUMMARY AND CONCLUSIONS 



1. Muscles absorb fluid from hyper-, iso-, and hypo-tonic solutions of electrolytes 

 and non-electrolytes. 



2. The sarcolemma of the muscle is permeable to the ions Na, K, Ca, Mg, Ba. 

 NH4, Li, CI, Br, I, NO3, SO4, C2O4, CO3, CgHsO,, in both directions, but at a 

 much slower rate outward than inward. 



3. Osmotic effects account only for absorption from water and cane sugar 

 solutions. 



4. Specific ionic effects play an important role in absorption from solutions of 

 electrolytes. The "ion-proteid" theory seems to fully explain all cases noted. 



5. The effect of the anion is marked in solutions of the salts known as saline 

 cathartics. Instead of an inhibiting effect on absorption, these anions favor this pro- 

 cess to a certain degree. 



6. Absorption from isosmotic solutions depend on (1) the nature of the sub- 

 stance in solution, (2) time of action of the solution, (3) relative permeability of 

 sarcolemma, (4) physical state of the muscle, and (5) temperature at which absorption 

 takes place. 



7. K, NH4, Ba, and Mg cations seem to favor absorption, Na and Li are indif- 

 ferent, while Ca cations show a marked inhibiting action on this process. 



8. The anions CI, Br, I, and NO 3 act indifferently toward the process of absorp- 

 tion, while anions of the SO^ group show a positive effect. 



In conclusion I wish to thank Professor Loeb for his many valuable suggestions 

 both as regards methods of experimentation and interpretation of the results obtained. 



ADDENDUM 



Since the manuscript of the above article was sent to press, two articles by E. Overton on 

 allied subjects, have appeared: "Beitrage zur allgemeinen Muskel- und Nervenphysiologie," 

 Archivf. d. ges. Physiol, Vol. XCII (1902), pp. 115 ff.; ibid., pp. 346 ff. 



These articles, although bringing out certain facts mentioned in above paper, show that 

 Overton is not familiar with the entire literatiu-e of the subject 



It is hard to explain the known facts concerning nutrition, as well as those previously 

 brought out by Loeb on rhythmic contraction of muscle under influence of certain ions, without 

 granting the permeability of the muscle plasma for the ions in question. This fact is absolutely 

 contradicted by Overton. 



The second paper, dealing with the influence of Na ions on muscle contractility, is, on the 

 whole, a confirmation of Loeb's work published in 1899 and 1900. 



REFERENCES 

 Atkinson, J. P. 



"The Fractional Precipitation of Globulin and Albumin of Normal Horse's Serum and 

 Diphtheria Antitoxic Serum, and the Antitoxic Strength of the Precipitates." Jour. Exp. 

 Med., Vol. V (1900), pp. 67 ff. 



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