CHLOROFORM A POISON 



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partly in loose chemical combination does not radically affect 

 the problem of its absorption, for we can make the definite 

 statement that any increase in alveolar concentration produces 

 an appreciable increase in the amount in the blood. 



During the absorption of chloroform by the organism the 

 vapour passes from the alveoli to the blood, and thence to the 

 lymph. It follows that the vapour pressure of the drug must be 

 higher in the alveolar air than in the blood, and higher in the 

 blood than in the lymph. We note, in addition, that if the chloro- 

 form vapour pressure in the inspired air be kept constant, this 

 pressure must be higher in the expired air, which again must 

 be higher than in the alveolar air. There is thus a descending 

 scale of vapour pressure in the inspired air, the expired air, the 

 alveolar air, the blood, and the lymph. So long, then, as chloro- 

 form is being absorbed it is with such a condition as this that 

 we are dealing. This scale can be rendered diagrammatically 

 as follows : 



Pressure 'in ■ f ^ ns pi re d Air. Expired Air. Alveolar Air. Blood. 



Lymph. 



The steepness of this scale will be greatest at the beginning 

 of anaesthesia, and will gradually diminish as anaesthesia 

 advances. It is only the first step in the scale that we are 



