412 



SCIENCE. 



[N. S. Vol. IV. No. 91. 



place in short operations, sucli as tooth ex- 

 traction. In the birthplace of anaesthesia 

 ether has always maintained its ground ; 

 but in Europe it was to a large extent dis- 

 placed by chloroform till recently, when 

 many 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 princi- 

 ples, 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 oc- 

 casioned 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 surgery became widely ex- 

 tended, since many procedures in themselves 

 desirable, but before impossible from the 

 protracted agony they would occasion, be- 

 came 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 the 

 first to last a gift of science. Nitrous ox- 

 ide, sulphuric ether and chloroform are all 

 artificial products of chemistry, their em- 

 ployment as anaesthetics was the result of 

 scientific investigation, and their adminis- 

 tration, 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 knowl- 

 edge. 



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 

 afibrd strong confirmation of the great gen- 

 eralization that living matter is of the same 



essential nature wherever it is met with on 

 this planet, whether in the animal or vege- 

 table kingdom. Anaesthetics have also, in 

 ways to which I need not here refer, power- 

 fully 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 thej^ first engaged his at- 

 tention was that they were occasioned prima- 

 rily by the oxygen of the air acting upon un- 

 stable animal or vegetable products, which, 

 breaking up under its influence, communi- 

 cated disturbance to other organic materials 

 in their vicinity, and thus led to their de- 

 composition. Cagniard-Latour had, indeed, 

 shown several years before that yeast con- 

 sists essentially of the cells of a microscopic 

 fungus which grows as the sweetwort fer- 

 ments ; and he had attributed the breaking 

 up of the sugar into alcohol and carbonic 

 acid to the growth of the micro-organism. 

 In Germany Schwann, who independently 

 discovered the yeast plant, had published 

 very striking experiments in support of 

 analogous ideas regarding the putrefaction 

 of meat. Such views had also found other 

 advocates, but they had become utterly dis- 

 credited, largely through the great author- 

 ity of Liebig, who bitterly opposed them. 



Pasteur, having been appointed as a 

 young man Dean of the Faculty of Sciences 

 in the University of Lille, a town where the 

 products of alcoholic fermentation were 

 staple articles of manufacture, determined to 

 study that process thoroughly ; and, as a re- 

 sult, he became firmly convinced of the cor- 

 rectness of Cagniard-Latour's views regard- 

 ing it. In the case of other fermentations, 

 however, nothing fairlj^ comparable to the 

 formation of yeast had till then been ob- 

 served. This was now done by Pasteur for 

 that fermentation in which sugar is resolved 

 into lactic acid. This lactic fermentation was 

 at that time brought about by adding some 



