1906.] 



Chloroform in the Blood of Animals. 



417 



The two experiments he records, which show the amounts of chloroform 

 in the brain and blood of dogs killed with chloroform, are not concordant : — 

 Grammes of chloroform Grammes of chloroform 



The methods and mode of conducting the experiments detailed in Papers I 

 and IV (appendices to the Eeport of the Special Chloroform Commission of 

 the British Association)* do not come into consideration here since the work 

 was chiefly undertaken with the view of ascertaining how far weighed amounts 

 of liquid chloroform could be recovered from the tissues of small animals 

 (Dodgson) or from the blood of animals anaesthetised or killed by chloroform, 

 the blood being examined quantitatively for chloroform at periods varying from 

 1 to 10 days after the blood had been removed from the body (J. H. Wells). 



Since the recent work of Tissotf and XiclouxJ is directly comparable with 

 that which we have undertaken, their method and results will be given in 

 somewhat greater detail. The method of the French observers J. Mansion 

 and Tissot,§ and also that employed by Nicloux, depends on Dumas' 

 reaction, the production of potassium chloride when chloroform is treated 

 with alcoholic potash. As applied to the estimation of chloroform in urine 

 or blood outside the body, or blood withdrawn from different parts of the 

 circulation, the method consists in distilling off the chloroform from 

 defibrinated blood or other liquid which has been rendered acid with 

 alcoholic solution of tartaric acid. The distillate is boiled with alcoholic 

 potash, cooled, neutralised with sulphuric acid, using phenolphthalein as 

 an indicator, and titrated with silver nitrate, using potassium chromate 

 as an indicator (Nicloux). The error of the method averages 2 per cent. 

 (Nicloux), while Tissot and Mansion show that 96*1 per cent, of the total 

 chloroform added can be obtained from blood treated as above. The 

 method adopted of distilling off chloroform from tissues after acidification 

 is the usual toxicological method. One of us (J. A. G.) has been in the 

 habit of frequently using this method of investigation in toxicological 

 practice, and in his experience every trace of chloroform cannot be readily 

 extracted and accurately estimated when only a few milligrammes are 

 present. Without wishing to impugn in the slightest degree the accuracy 

 of the control experiments of Nicloux, we are of opinion that the exact 



I 

 II 



in blood. 



0-015 

 0-043 



in brain. 



0-0418 

 0-036 



* ' Brit. Med. Journ.,' July 11, 1902. 

 t ' Comptes Eendus,' No. 5, 1906. 



\ Nicloux, 'Comptes Rendus,' No. 2, 1906 ; No. 3, 1906 ; No. 7, 1906. 

 § J. Tissot, ' Comptes Eendus,' No. 4, 1906. 



