I4 SCIENCE PROGRESS 



A properly constructed apparatus should remove this dread from 

 his mind. 



The writer would suggest that three factors are concerned in 

 the safe administration of chloroform, namely : 



(i) A knowledge of the physics of the absorption of 

 chloroform. 



(2) A knowledge of the percentage of chloroform inhaled. 



(3) A careful observation of the patient's condition. 



He proposes to deal with these three factors in the above order. 



I. The Absorption of Chloroform 



Unless we are to assign a selective action to the pulmonary 

 epithelium, an action similar in characterto that which Haldane and 

 other workers have shown probably to exist in regard to oxygen, 

 we must conclude that chloroform passes through the epithelium 

 of the alveoli, and is dissolved in the blood according to the 

 physical laws which govern the diffusion of vapours and their 

 solution in liquids. The recent researches of Moore and Roaf 

 {Proceedings of the Royal Society, 1904, vol. lxiii. p. 382) have, 

 however, demonstrated that the blood proteids form loose com- 

 pounds with chloroform, and hence that chloroform exhibits a 

 greater solubility in blood than in water. We thus establish 

 a similarity between the relation of oxygen and chloroform to 

 blood, oxygen being associated with the haemoglobin and chloro- 

 form with the proteids. Further, Byles, Harcourt, and Horsley 

 have found that blood with corpuscles has a greater retaining 

 power for chloroform than simple plasma. Such observations 

 indicate that chloroform exists in the blood not only in solution 

 in the plasma, but also in a condition of combination with the 

 proteids and some constituent or constituents of the corpuscles. 

 Hence the solution of chloroform in blood does not solely 

 depend on the physical laws governing the solution of vapours 

 in liquids, but, as in the case of oxygen, other factors come 

 into play. But of one thing we can be certain — namely, that 

 slight increases in alveolar concentration of chloroform produce 

 appreciable changes in the pressure of chloroform in the blood, 

 as shown by the condition of the patient. In this respect chloro- 

 form differs widely from oxygen, for large differences in oxygen 

 alveolar concentration can occur without producing any altera- 

 tion in the individual (Haldane, Journal of Physiology, vol. xxxii. 

 p. 225). The fact, then, that chloroform exists in the blood 



