422 Messrs. G. A. Buckmaster and J. A. Gardner. [July 11, 



No difference whatever could be detected, either spectroscopically or by 

 using Haldane's method of examining very dilute solutions of blood in long 

 glass tubes, between the condition of the haemoglobin before and after 

 lj hours' continuous chloroform narcosis. 



However, positive information that CO-haemoglobin is present can be at 

 once obtained by the above methods when 0*5 c.c. pure CO was added and 

 shaken up with 73 c.c. of the same blood which had failed to give any 

 indication of CO-haemoglobin. We are therefore unable to accept the view 

 that the combustible gas stated to appear during chloroform narcosis is 

 carbon monoxide, a product of the decomposition of chloroform within the 

 organism. The recognition of CO-haemoglobin is quite easy when 1/10 

 to 1/20 of the total colouring matter of the blood has taken up carbon 

 monoxide. 



I. — Determination of the Amount of Chloroform in Blood. 



In the experiments described in this paper the amount of chloroform in 

 the blood was calculated from the difference in the chlorine-content of the 

 blood before and after administration of the anaesthetic. The validity of this 

 mode of estimation depends, of course, on the constancy of the natural 

 chlorine-content of the blood during the whole course of an experiment. 

 We fully satisfied ourselves, however, by a series of preliminary observations, 

 some of the results of which are given later, that under the conditions 

 of all our experiments the percentage of natural chlorine did remain 

 sufficiently constant. 



Method. — The animal experimented on was anaesthetised by ether and the 

 necessary operations for introducing cannulae into the carotid artery and the 

 trachea were performed. The tracheal cannula was fitted to a Chauveau's 

 valve and a side-tube in connection with apparatus for recording the rate and 

 character of the respirations. Chloroform was administered sometimes by 

 means of a Woulffs bottle, sometimes from bags filled with mixtures of air 

 and chloroform vapour of known composition by means of the Dubois 

 apparatus. The samples of blood were taken from the carotid artery and 

 collected in stoppered weighing tubes. As a rule the ether was cut off 

 after the operation had been performed, and the animal allowed so far to 

 recover that the conjunctival reflexes reappeared and the anaesthesia was 

 light. A control sample was then taken in order to determine the percentage 

 of natural chlorine. After this, chloroform was administered and samples of 

 blood were taken during various stages of anaesthesia. No blood-pressure 

 observations were taken, as we thought it desirable to interfere as little 

 as possible with normal physiological conditions. During the experiments 



