374 SIR THOMAS R. FRASER AND MR ALISTER T. MACKENZIE ON 



D. Effects on Skeletal Muscles. 



Among the general effects following the injection of S. sarmentosus, there were 

 noted early slight rigidity of the muscles, the appearance of fibrillary twitches in 

 them, and subsequently enfeeblement followed by paralysis of the muscles ; and 

 soon after death, the muscles were observed to be pale, rigid, non-contractile and 

 acid in reaction. Experiment XLV. showed that muscles unprotected from the 

 action of S. sarmentosus were pale, rigid and acid in reaction within 3 hours ; and 

 in 3^- hours they failed to respond to direct electrical stimulation. On the other 

 hand, muscles protected from the extract responded to direct electrical stimulation 

 for 24 hours, and did not become rigid within that time. 



Several experiments were made in order to obtain graphic records of some of the 

 changes produced in muscle. For this purpose, the procedure was to make two muscle 

 preparations with the gastrocnemii of a frog in which the muscles were not separated 

 from the femur, and retaining the tendo Achillis and the portion of the femur to which 

 the muscle is attached. Each preparation was placed in a small glass cylinder, closed 

 at its lower end by a cork. Through this cork passed a piece of stout platinum wire, 

 whose upper end was hooked so as to fix the attached portion of the femur ; while the 

 other end was connected with one pole of an induction coil. The tendo Achillis of the 

 muscle was attached to a light lever writing on a smoked surface. To complete the 

 electrical circuit, a piece of fine platinum wire was hooked into the tendo Achillis, and 

 its free end was connected with the "Other pole of the induction apparatus. Single- 

 break shocks from a Du Bois Reymond's apparatus and a single Daniell's cell were 

 used as stimuli, and the wires from the two muscles were so connected that each 

 stimulus passed simultaneously through both muscles, and in the same direction along 

 each muscle. The muscles were immersed in Ringer's solution. One muscle was used 

 as a control throughout the experiment, and the solution surrounding the other was 

 afterwards replaced by a solution of extract in Ringer's solution. The position of the 

 secondarv coil is indicated on the tracings. It was found that the muscles of Rana 

 temporaries were more affected by the extract than those of Rana esculenta. 



Experiment L. — Effect on the muscles of Rana temporaria of extract of S. sar- 

 mentosus dissolved in Ringer's solution (1 in 1000) (Plate II.). Muscle A is the 

 control and muscle B the poisoned muscle. Before poisoning, normal curves were 

 taken with the secondary coil at 100 mm., as at 12.23 p.m. (fig. 1). 



12.25. 2 c.c. of solution of S. sarmentosus extract (1 in 1000) substituted for the Ringer's solution of 



muscle B. 

 12.50. No change (fig. 2). 

 12 52. Within the last 2 minutes the lever of B had risen owing to shortening of the muscle. The 



rise was gradual and there were no visible fibrillary twitches. 

 12.55. Spontaneous fibrillary twitches of B were visible, and the lever was jerked up by some of them. 



After stimulation at 100 mm. and contraction of the muscle (fig. 3), these fibrillary twitches 



became very coarse. 



