210 BIO-CHEMICAL JOURNAL 



tannin. The amount of tannin added was intentionally less than that 

 required for complete precipitation, so that the filtrate contained a 

 little unaltered gelatin, but no tannin. 



3. Action of Chloroform 



Moore and Roaf 1 have shown that electrolytes are set free in 

 blood by the action of chloroform. 



4. Excitation, Injury, and Death 



Macdonald z found that, as a result of injury, potassium salts are 

 set free in the axis-cylinders of nerve fibres. Under certain conditions 

 these salts may be taken up again by the colloids, and Macdonald 

 suggests a theory of excitation and inhibition on this basis. 



Hoeber 3 finds that the excitability, the capacity of staining, and 

 the colloidal consistency of nerve vary concurrently. 



Wakelin Barratt 4 finds that chlorine ions are set free when 

 unicellular organisms are injured or killed. 



Brailsford-Robertson 5 , as the result of his work on the 

 phenomena of the heart-beat, comes to the conclusion that these 

 phenomena are such as would be expected if there were a periodic 

 driving out by anions of kations from combination with proteid. 



Howell, 6 having found that the vagus cannot exert its action on 

 the heart-muscle in the absence of potassium ions, brings forward the 

 hypothesis that the inhibition produced by the vagus is due to splitting 

 off potassium from combination in the muscle. 



In order to see whether there is any evidence of a sudden 

 separation of electrolytes at the moment of death, I have made the 

 following experiment : 



The skins of two frogs were immersed in isotonic cane-sugar 

 solution. The electrical resistance of the solution was measured, after 

 soaking for some time, and found to be at 11 C, 6407 ohms. The 

 solution containing the skins was then slowly warmed and the 

 resistance determined at frequent intervals up to 56 C. The 



1. Proc. Roy. Soc., 73, p. 382, 1904, and 77 B, p. 98, 1906. 



2. Thompson-fates L-.i>. Reports, Vol. 4, p. 213, 1902. 



3. Ccntralb.f. Physiologic., XIX, page 390, 1905. 



4. Zeitsch. f. Altgem. Physiologie, V, page 33, 1905. 



5. Pflugcr's Archi-v. 1 10, page 623, 1905. 



6. American Jcurn. of Physiology, XV, page 291, 1905. 



