166 THE MAIN CURRENTS OF ZOOLOGY 



outline. Although the general use of anaesthetics in 

 surgery dates from 1846, there are scattered refer- 

 ences in classical writers, in mediaeval literature and 

 in other sources, to show that there was at least 

 occasional employment of hemp, of mandrake and 

 other opiates, to produce insensibility to pain during 

 surgical treatment. Vapors of a certain kind of 

 hemp were used in ancient times, Mandragora was 

 used in the thirteenth century in Italy, and it is 

 recorded that, in 1782, Augustus, King of Poland, 

 underwent an amputation while rendered insensible 

 by a narcotic. But these occurrences were inciden- 

 tal and led to no general use of pain-dispelling agents. 



In 1787, Sir Humphrey Davy experimented upon 

 himself with the effects of nitrous oxide, commonly 

 called "laughing gas." His experiments were in- 

 teresting, and although he did not inhale the gas 

 to the point of complete insensibility, he made the 

 suggestion that it might be useful in surgical practice. 



Again, in 1818, Faraday observed the pain-dis- 

 pelling effects of inhalation of the vapor of ether, 

 and in 1822, 1833 and 1834 similar observations were 

 reported by certain American physicians. But no 

 practical outcome resulted. These observations ap- 

 pear "to have been regarded in the light of mere 



