392 



Dr. E. H. Embley. 



[June 13, 



5 per cent., sold under the name of " Somnoform," was investigated by 

 Cole (3). 



Cole's experiments were performed for the most part upon rabbits, but in 

 three cases cats were used. The quantity of Somnoform in the air inspired 

 was not ascertained. Cole found the effect upon the respiration to be at 

 first stimulative, followed, when large doses were employed, by standstill of 

 the respiration, with the diaphragm in a condition of tonic contraction. 

 The changes in the circulation were increased rate and diminished power of 

 cardiac contractions and gradual fall of blood-pressure. ISTo effect upon the 

 vaso-motor system was discovered. The vagus endings in the heart were 

 paralysed. 



Interesting clinical observations have been reported by McCardie (1), 

 Hewitt (4), and others. 



McCardie's papers are particularly valuable, as, besides detailing the 

 results of an extensive personal experience with this anaesthetic, he has 

 collected as far as possible the experience of others at home and on the 

 Continent. 



The present paper records the results of work undertaken with a view to 

 studying the pharmacology of ethyl chloride, in the hope that this might be 

 of some value to those who may be concerned with its administration, and 

 with the view of saving what appears to me to be a valuable anaesthetic 

 agent from coming under the suspicion of being unduly dangerous. 



For better comparison with the effects of chloroform, which have been 

 frequently studied, dogs were used in all of the experiments, since these 

 animals have been generally employed in chloroform research. In all 

 experiments morphine and ether were used as the preliminary anaesthetics. 



The Solubility of Ethyl Chloride in Water and Blood. 



Ethyl chloride vapour I find to be soluble in water to the extent of 

 253'36 per cent, by volume (0 - 678 per cent, by weight) at 21° C. and at 

 760 mm. I have also ascertained the extent of its absorption by blood. 

 There was considerable difficulty in determining this in consequence of the 

 blood becoming of a tarry consistence as the absorption increased. In this 

 condition the absorption progressed very slowly • for instance, in one experi- 

 ment in which 100 c.c. of blood was employed and 496 c.c. of ethyl chloride 

 vapour had already been absorbed, it required eight hours' contact, with 

 continual shaking, for absorption of a further 5 c.c. In consequence of this 

 physical difficulty, the complete absorptive power of blood for ethyl chloride 

 was not determined. It is only possible to state that blood at 38° C. takes 

 up an amount exceeding 500 per cent, by volume of the vapour. 



