Chloroform in the Blood of Animals. 



415 



In 1860, Lallemand Perrin and Duroy* investigated the quantity of 

 chloroform in the hlood and tissues of dogs killed with the anaesthetic. 

 The chloroform in the blood was cleared out of this by heating in a current 

 of air drawn through the blood, and the vapour was conducted through a red- 

 hot glowing porcelain tube. The hydrochloric acid so formed was estimated 

 by titration. They found 100 grammes of blood contained 1 c.c. of 

 chloroform vapour. 



In 1883, Grehant and Quinquaudf published seven observations in which 

 they determined the quantity of chloroform in the blood of dogs at the 

 moment of anaesthesia, which was induced by the inhalation of 10 per cent, 

 of chloroform vapour in air supplied by an apparatus which they had 

 designed for administering variable amounts of chloroform. In their method 

 the blood is removed without coming in contact with the air, and introduced 

 into an apparatus for distilling in vacuo. At a temperature of 40° C, the 

 blood gases are evolved, and at 65° C. the chloroform is distilled off. They 

 state that almost all the chloroform in the blood is evolved as vapour wiih 

 the blood gases. The receiver with the vapour and gases is washed out 

 four to five times with water and added to the distillate. This liquid is 

 sealed up in a tube, from which all the oxygen had been displaced by carbon 

 dioxide, with Fehling's solution and heated. The amount of reduction was 

 estimated by ascertaining the quantity of chloroform and water, a known 

 weight of chloroform being used, which produced a similar amount of 

 reduction of the same quantity of Fehling's fluid. 



The quantities of blood used for these determinations were about 90 to 

 96 c.c, and the amount of chloroform in 1800 to 2181 grammes of blood was 

 found to be 1 gramme. They concluded that about 50 milligrammes of 

 chloroform per 100 grammes of blood is the anaesthetic dose, and this is 

 only slightly less than the amount present in animals killed with 

 chloroform. 



Pohl in 1890+ used a slight modification of the method which 

 Schmiedeberg,| who had adversely criticised the method employed by 

 Lallemand Perrin and Duroy, introduced in 1867. AVorking with de- 

 fibrinated blood and liquid chloroform, he determined the chloride produced 

 when chloroform vapour is passed over glowing lime at a red heat. The 

 calcium chloride is washed out of the tube with nitric acid, the liquid is 

 neutralised with litmus and titrated with silver nitrate. The method 



* ' Du Role de l'Alcool et des Anesthesiques dans l'Organisme,' Paris, 1860. 



t 'Comptes Rendus des Seances de l'Acadeniie des Sciences,' 9, vol. 97, p. 753, 1883. 



\ 'Arch. f. exp. Path. u. Pharniak.,' vol. 28, 1890-91. 



§ ' Arch. f. Heilkunde,' p. 273, 1867. 



