492 ON THE INTERDEPENDENCE OF SCIENCE 



the thigh as painlessly, with less complicated anaesthetic apparatus, by aid 

 of another agent, chloroform, which was being powerfully advocated as a sub- 

 stitute for ether by Dr. (afterwards Sir James Y.) Simpson, who also had the 

 great merit of showing that confinements could be conducted painlessly, j^et 

 safely, under its influence. These two agents still hold the field as general 

 anaesthetics for protracted operations, although the gas originally suggested 

 by Davy, in consequence of its rapid action and other advantages, has taken 

 their place in short operations, such as tooth extraction. In the birthplace 

 of anaesthesia ether has always maintained its ground ; but in Europe it was 

 to a large extent displaced by chloroform till recently, when man^^ have returned 

 to ether, under the idea that, though less convenient, it is safer. For my own 

 part, I believe that chloroform, if carefully administered on right principles, is, 

 on the average, the safer agent of the two. 



The discovery of anaesthesia inaugurated a new era in surgery. Not only 

 was the pain of operations abolished, but the serious and sometimes mortal 

 shock which they occasioned to the system was averted, while the patient was 

 saved the terrible ordeal of preparing to endure them. At the same time the 

 field of surger}^ became widely extended since many procedures in themselves 

 desirable, but before impossible from the protracted agony they would occasion, 

 became matters of routine practice. Nor have I by any means exhausted the 

 list of the benefits conferred by this discovery. 



Anaesthesia in surgery has been from first to last a gift of science. Nitrous 

 oxide, sulphuric ether, and chloroform are all artificial products of chemistry, 

 their employment as anaesthetics was the result of scientific investigation, and 

 their administration, far from being, like the giving of a dose of medicine, 

 a matter of rule of thumb, imperatively demands the vigilant exercise of 

 physiological and pathological knowledge. 



While rendering such signal service to surgery, anaesthetics have thrown 

 light upon biology generally. It has been found that they exert their soporific 

 influence not only upon vertebrata, but upon animals so remote in structure 

 from man as bees and other insects. Even the functions of vegetables are 

 suspended by their agency. They thus afford strong confirmation of the great 

 generalization that living matter is of the same essential nature wherever it is 

 met with on this planet, whether in the animal or vegetable kingdom. Anaes- 

 thetics have also, in ways to which I need not here refer, powerfully promoted 

 the progress of physiology and pathology. 



My next illustration may be taken from the work of Pasteur on fermentation. 

 The prevailing opinion regarding this class of phenomena when they first engaged 

 his attention was that they were occasioned primarily by the oxygen of the 



