Scientific Proceedings. 



23 



small quantity, and compared with its mate irrigated only by the 

 indifferent fluid, a fatigue record being made from both, more in- 

 tense contractions frequently occur in the poisoned muscle at the 

 beginning of the experiment, and may last until exhaustion sets 

 in. When a fatigue record is being made from a muscle with the 

 circulation intact, intravenous injection of a fatigue substance 

 causes augmentation of contraction. The author concludes that 

 the treppe is due to the augmenting action of fatigue substances 

 in small quantities — the same substances which in larger quantities 

 cause depression or fatigue. 



An excellent mode of demonstrating the augmenting action of 

 C0 2 in the cat is to record the contractions of the tibialis anticus 

 in the living animal, and while the record is being made, to clamp 

 the trachea. A marked treppe follows. 



If two corresponding muscles be compared, one with the circu- 

 lation intact, and the other with its arteries ligated, the latter 

 muscle performs more intense contractions and exhibits a more 

 rapidly developing treppe, owing to the accumulation of fatigue 

 substances. 



The chemical theory of the treppe is able to explain several 

 other known phenomena. The author has experimented on both 

 frogs and cats. The augmenting action of the fatigue substances 

 seems to be observed even when curare is employed. 



20 (163) 



The influence of the red corpuscles upon the viscosity of the 



blood. 



By RUSSELL BURTON-OPITZ. 



\_From the Physiological Laboratory of Columbia University, at the 

 College of Physicians and Stir g eons. ] 



The method by means of which the following determinations 

 of the viscosity were made has been described in Pfluger's Archiv, 

 Vol. 82, p. 464. 



Having determined the coefficient for fresh ox serum at 37 0 C. 

 the serum was gradually concentrated by the addition of definite 

 quantities of red blood corpuscles (washed). The viscosity of the 

 M blood" was tested after each addition of corpuscles. 



