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DR FRASER ON THE PHYSIOLOGICAL ACTION 



having previously been closed, a bent steel tube was substituted by which means the blood 

 could be readily passed into a small absorption tube over mercury, without coming in contact 

 with the atmosphere. 



The vein was now ligatured, and the dog was poisoned with a moderate dose of the extract. 

 At the moment of death, a second quantity of blood was withdrawn with the same precautions as 

 the first, and it was placed in a similar absorption tube. A nearly equal portion of atmo- 

 spheric air was added to each tube, and they were frequently shaken during twenty- four hours 

 in a room with a temperature that varied little from 50° F. The gases were then removed and 

 analysed. The following are the results : — 



Gases from Blood before Poisoning. 



Volume of blood = 777 cub. cent. 



air = 4795 

 After contact with the blood for 24 



hours, air measures 51-65 c. c. 

 .•. Apparent exhalation = 370 c. c. 



Gases from Blood after Poisoning. 

 Volume of blood = 4'03 cub. cent. 



air = 48-20 

 After contact with the blood for 24 hours, 



air measures 50-54 c. c. 

 .'. Apparent exhalation = 2-34 c. c. 



Composition per cent. : — 





Composition per cent. : — 





Oxygen, . 



20-63 



Oxygen, 



19-93 



Nitrogen, . 



77-82 



Nitrogen, 



78-77 



Carbonic acid, 



1-55 



Carbonic acid, 



1-30 



100- 100- 



These results agree sufficiently to prove that the respiratory function of the 

 blood is not interfered with in physostigma poisoning. Had there been any 

 marked discrepancy, a suspicion of such an action might be raised ; but I doubt 

 if this could be really settled without a much more refined method of experiment 

 than was adopted. Harley's results seem open to very many objections, as his 

 usual method permitted of an even greater number of fallacies than were pos- 

 sible in the two experiments I performed. At the same time, his paper is an 

 extremely valuable and elaborate one, and contains many conclusions of the 

 highest interest to physiologists. 



Action on the Lymph-hearts op the Frog. 

 The lymph-hearts discovered by Muller* and PANizzAf in amphibia, have 

 always been found paralysed at an early stage of the poisoning, in the experi- 

 ments where their condition was examined. As the pulsations of the pair situated 

 one on each side of the sacrum of frogs may be readily determined without any 

 operation, attention was especially directed to them. The time at which they 

 cease to contract is noted in the following experiment; and the previous increase 

 in rapidity that is there mentioned has been observed on other occasions. 



Experiment LXVI. 

 The lymphatic hearts in the ischiadic region of a frog had an average rate of forty-nine 

 contractions in the minute. Five minutes after two grains of extract had been subcutaneously 



* Philosophical Transactions, 1833, p. 559. 



-J- Proceedings of the Royal Society of London, vol. ix. p. 559. 



