On the Physical Relation of Chloroform to Blood. 55 



" On the Physical Relation of Chloroform to Blood." By A. D. 

 WALLER, M.D., F.R.S. Received May 5, Read June 9, 1904 



In connection with the preliminary communication by Moore and 

 Roaf on certain physical and chemical properties of solutions of chloro- 

 form in water, saline, serum, and haemoglobin,* it may be of interest 

 to publish the following communication. The close similarity of the 

 conclusions arrived at independently by different observers is such as 

 to render the two communications mutually corroborative, and although 

 the present communication forms part of a report by A. D. Waller and 

 J. H. Wells, which is technically the property of a Special Chloroform 

 Committee of the British Medical Association, there is obviously no 

 reason why it should be withheld from publication. It was originally 

 presented as long ago as June 19, 1903, and I have since that time 

 extended the experimental data upon which the conclusion rests. In 

 order, however, to preserve the complete independence of the two 

 contributions I have preferred to communicate it in its original, and 

 perhaps imperfect, form. The importance of the blood as a chloroform 

 carrier, by reason, presumably, of an easily dissociable compound, is 

 the conclusion of principal importance arrived at in both series of 

 investigations. 



The original text of the report is as follows : 



" Our attempts to recover a known weight of chloroform from blood, 

 by the French method (extraction in vacua followed by digestion with 

 alcoholic potash and titration of chlorides), led us to make two simple 

 experiments that very strikingly illustrate the fundamental difference 

 between blood and simple salt solution or water as regards their 

 absorptive power towards chloroform vapour. The first of these 

 experiments shows that equal volumes of blood and of normal saline 

 are capable of absorbing very different volumes of chloroform vapour. 

 The second shows the converse fact that very different volumes of 

 chloroform vapour are obtainable by evacuating equal volumes of 

 blood and of water, or of normal saline. In the first experiment the 

 absorption by blood is greater than that by water. In the second 

 experiment the delivery from blood is less than that from water. The 

 inference from these two data is that blood possesses greater affinity 

 for chloroform than does water, and that, therefore, in the transfer of 

 chloroform by blood from the pulmonary air to the nervous centres 

 that fluid does not act as a simple solvent, but rather as a temporary 

 retaining and restraining medium, that helps to convert irregular into 

 constant flow. The blood has thus a controlling effect upon the 

 process of anaesthesia that may be compared to the action of a fly- 



* Communicated by Professor Sherrington, received April 12, read May 5, 1904. 

 [Ante, pp. 382412.] 



