RESEARCHES ON CHLOROFORM ANAESTHESIA 633 



reduction in vigour to a certain extent and no more. No matter 

 how prolonged was the passage of the chloroform solution, the 

 effect rapidly disappeared when the anaesthetic was removed. 

 Secondl}', the effect upon the living cells of the heart muscle 

 depended solely upon the concentration (solution tension or 

 osmotic pressure) of the chloroform in the cell for the time 

 being; and, lastly, the effect at any moment was not at all 

 due to the total amount of chloroform which had been supplied 

 to the heart up to that particular time. Experiments of this 

 nature suggested the view that the effect might be due to some 

 unstable association or combination between the anaesthetic 

 and the cell protoplasm of muscle, and that this existed for 

 only so long as the pressure of the anaesthetic was maintained. 

 Diminish this pressure to zero and complete recovery takes 

 place, the association ceasing to exist ; re-establish the pressure 

 and the effect of the anaesthetic once more is witnessed. In the 

 opinion of the writer no other view than this is possible. The 

 condition of chloroform anaesthesia in man can be most satis- 

 factoril}^ comprehended by considering that from the commence- 

 ment of the inhalation of an air-and-chloroform mixture the 

 pressure of the anaesthetic augments in the blood, and it is 

 this pressure which first of all forces the drug into the lymph 

 and then into the cells of the bod}^ some of these being more 

 permeable and therefore more susceptible than others ; the 

 degree of anaesthetisation of the cells being due not so much 

 to the absolute quantity of chloroform supplied, as to the 

 m.aintenance of a definite pressure of the anaesthetic in the 

 blood. From a large number of experiments which the writer 

 has witnessed, it is clear that no definite fixed relation exists 

 between the proportion of chloroform in the blood and the effect 

 of the drug, for this is determined not by the absolute amount 

 which is held, but by the actual quantity which passes into the 

 cells of the central nervous system, so that the control of these 

 over the liberation of energ}^ by the organism is reduced to a 

 minimum. 



Since in the higher animals arterial blood is the vehicle 

 by which chloroform is taken up from the surrounding medium 

 and a certain solution pressure of the drug must be attained 

 before anaesthesia occurs, the relations which may exist between 

 blood and chloroform have been the subject of much investiga- 

 tion. The proteins of the blood, both those in the plasma and 



