EFFECT OF VENOM ON ISOLATED HEART. 123 



cent; No. 4, 0.01 per cent; No. 5, control. At 4 h 30 m all beating feebly and 

 irregularly. Add to each 1 to 10,000 CaCl 2 , all beats strengthened. At 6 

 p. m. all beating feebly. Make all solutions up to 0.03 per cent CaCl 2 and 0.02 

 per cent KC1. At 7 p. m. all have ceased. Transfer to normal NaCl solution 

 for 30 minutes and then back to the old mixture. All begin to beat and con- 

 tinue for several hours. At 8 a. m. transfer all to plain NaCl solution. All 

 but No. 3 begin to beat. At 3 p. m. Nos. 2, 4, and 5 are still beating. At 4 

 p. m. Nos. 2 and 4 stopped and No. 5 stopped soon after. 



(5) Venom A . Venom dissolved in Ringer's solution containing venom as 

 follows: No. 1, 0.05 per cent; No. 2, 0.025 per cent; No. 3, 0.05 per cent, heated; 

 No. 4, 0.025 per cent, heated; No. 5, control. Heart removed at 12 noon and 

 placed in 0.85 per cent NaCl solution. 3 p. m. transfer to venom, all beat, No. 

 2 very feebly. 4 h 45 m p. m. all still beating; transfer to 0.85 per cent NaCl 

 solution, all beat. 6 p. m. transfer to venom, all beat feebly. 8 h 20 m p. m. all 

 still. 



(6) Venom A. To determine whether the slight effect of this venom was 

 due to inorganic constituents, 0.0106 gm. of the venom was incinerated, the ash 

 weighing 0.0012 gm. The heart was removed in the usual manner and placed 

 in normal salt solution containing venom as follows: No. 1, 0.05 per cent 

 venom; No. 2, 0.025 per cent venom; No. 3, ash from 0.05 venom; No. 4, ash 

 from 0.025 per cent venom; No. 5, control. Heart removed at 3 p. m. At 8 

 p. m. only No. 1 beating, add 0.02 per cent CaCl 2 to each. 12 p. m. all beating. 

 12 h 30 m a. m. No. 2 still, No. 5 very feeble. 7 a. m. all have ceased. 



(7) Venom B. Heart removed at 3 h 30 m p. m. and at 6 h 45 m p. m., after 

 latent period, placed in Ringer's solution containing venom as follows: No. 1, 

 0.04 per cent; No. 2, 0.04 per cent; No. 3, 0.04 per cent, heated; No. 4, 0.04 per 

 cent, heated; No. 5, control. At 8 p. m. all had stopped and on transfer to 

 plain 0.85 per cent NaCl solution only No. 5 beats. This continued several 

 hours; the others never beat again. 



(8) Venom B. Heart removed at 1 p. m. and placed in plain 0.85 per cent 

 NaCl solution. At 5 p. m. placed in Ringer's solution containing venom as 

 follows: No. 1, 0.08 per cent; No. 2, 0.04 per cent; No. 3, 0.02 per cent; No. 4, 

 0.01 per cent; No. 5, control. All stopped in about 3 hours, except control, 

 which continued for over 36 hours. 



(9) Venom B. Heart removed at 3 p. m. and placed in normal 0.85 per 

 cent NaCl solution containing venom as follows: No. 1, 0.016 per cent; No. 2, 

 0.008 per cent; No. 3, 0.004 per cent; Nos. 4 and 5, control. Only the controls 

 started to beat. The strips in the venom were immediately paralyzed and 

 none showed any tendency to recovery on being placed in normal 0.85 per cent 

 NaCl solution or Ringer's solution. They became so soft that they rolled up 

 into a ball by their own weight when the hook on which they were hung was 

 turned over. 



(10) Venom B. Heart removed at 3 p. m. and placed in normal NaCl 

 solution containing venom as follows: No. 1, 0.004 per cent; No. 2, 0.002 per 

 cent; No. 3, 0.001 per cent; No. 4, ash from 0.004 per cent; No. 5, control. 

 Only Nos. 4 and 5 started to beat, the others passing into the relaxed condition 

 described in the last experiment. 



(11) Venom C. Heart removed at 4 p. m. and the strips placed in NaCl 

 solution containing venom as follows: No. 1, 0.002 per cent; No. 2, 0.001 per 

 cent; No. 3, 0.0005 per cent; No. 4, 0.00025 per cent; No. 5, control. At 7 h 30 m 

 p. m. all were beating very feebly; added to each CaCl 2 3 to 10,000 and KC1 1 

 to 10,000. All start to beat. At ll h 30 m p. m. all still beating. At 12 p. m. 

 all have ceased except No. 5, which is still beating, but very slowly and feebly. 



