6h SCIENCE PROGRESS 



chloroform fairly often in the rough-and-ready fashion of the 

 Edinburgh school, without mishap or alarm, in my subsequent 

 laboratory experience I frequently lost animals by overdose of 

 chloroform, and for a time I took to ether instead. 



From this I was led to make a long series of experiments 

 on isolated nerve with ether and with chloroform vapours at 

 all kinds of percentages in air. Using the excitability of nerve 

 as my touchstone, I found that 10 per cent, chloroform vapour 

 was immediately and irremediably fatal, while ether vapour 

 at much higher percentage caused complete but only temporary 

 inexcitability. I studied in the same way many other anaesthetic 

 drugs — the chloromethanes and chloroethanes especially, and 

 chloroform itself at percentages from 0*5 to 5 per cent. I came 

 to the conclusion that chloroform is physiologically seven times 

 as powerful as ether, that as a certain and controllable anaesthetic, 

 chloroform is the best of the chloromethanes, and preferable to 

 any of the various chloroethanes that have been recommended 

 from time to time for clinical use, but that the safe administra- 

 tion of chloroform requires the continuous and uniform inhalation 

 of chloroform and air at between 1 and 2 per cent. — or, as I then 

 expressed it for the sake of emphasis, " not below 1 per cent, 

 not above 2 per cent." 



In the discussion that took place on the communication of 

 these results at the meeting of the British Medical Association 

 at Montreal 1 (1897) and in the following year at the Society 

 of Anaesthetists, the principal points of opinion elicited were to 

 the effect that it was certainly desirable that chloroform should 



1 Waller : " The Action of Anaesthetics on Nerve ; Ether and Chloroform," 

 Brit. Med. Journ., November 20, 1897. 



Waller: "On the Dosage of Chloroform," Brit. Med. Journ., April 23, 1898. 



Waller : "On the Administration of Chloroform to Man and to the Higher 

 Animals," Lancet, November 28, 1903. 



Waller : " On the Physical Relation of Chloroform to Blood," Proceedings of 

 the Royal Society, Vol. 74, 1904, p. 55. 



Waller and Geets : " The Rapid Estimation of Chloroform Vapour," Brit. Med. 

 Journ., June 20, 1903. 



Waller: "Chloroform Estimation by Densimetry" : "Ether Estimation by 

 Densimetry," Proceedings Physiological Society, July 11, 1903. 



Waller and Collingwood : " Estimation of Inspired and Expired Chloroform," 

 Proceedings Physiological Society, February 25, 1905. 



Waller: "A Physiological Contribution to the Problem of Chloroform 

 Anaesthesia," Brit. Med. Journ., December 24, 1904. 



Waller : " On the Action of Anaesthetics," Presidential address to the Physio- 

 logical Section of the British Association, Leicester, 1907. 



