March 20, 1896.] 



SCIENCE. 



423 



momentous, he undertook, ' in order to 

 discover the hidden properties ' of the 

 nerves and muscles, ' and to treat their 

 diseases more certainly.' To the jerks of 

 Galvani's frogs' legs we owe the discovery 

 of the galvanic battery and current, which 

 are named after him ; the telegraph and 

 ocean cable, with their immense influence 

 upon civilized life in peace and war ; the 

 transfer to miles of distance of the vast 

 working power of Niagara Falls. It is a 

 fitting, if slight, dramatic touch that the 

 traveller in Italy who passes the night at 

 Bologna, where Galvani worked and taught, 

 will perhaps put up at a hotel directly op- 

 posite the professor's modest house, and 

 will see that the tablet which records the 

 experiments made within is lighted up at 

 evening by the electric light, which also 

 owes its existence to a search for the hidden 

 ' properties ' of frogs' legs. 



Two hundred years ago there lived at 

 Delft, in Holland, a well-to-do Dutchman, 

 named Antony van Leeuwenhoek. He had 

 been a ' dry goods clerk ' in his j'outh, and 

 had had no learned or professional train- 

 ing. Van Leeuwenhoek took to making and 

 polishing, for his own use, very small and 

 very strong magnifying glasses, because he 

 was full of what some anti-vivisectionists 

 sneer at as 'scientific curiosity.' The 

 Dutchman's glasses were very superior ; 

 and with them he looked at the most mis- 

 cellaneous things — among these, at ditch 

 water and at particles from the surface of 

 his own teeth. He found that such matters 

 were swarming with living things of all 

 kinds, and described them and other things 

 so well that he became famous, and princes, 

 who were not ashamed to be interested in 

 ' mere science,' sent for him and his glasses 

 to instruct them. Among Van Leeuwen- 

 hoek's discoveries were the minute things 

 now called bacteria, or microbes, and known 

 to be living plants. The physicians were 

 prompted to guess that diseases might be 



due to the ravages of the new forms of mi- 

 croscopic life first seen with decisive clear- 

 ness by Van Leeuwenhoek ; but no proof 

 of this was forthcoming, and the idea was 

 abandoned by most, amid the laughter of 

 many at this fad of the doctors. More than 

 a centuiy went by. The bacteria, as ob- 

 jects of pure science, were more and more 

 studied. The microscope was bettered 

 more and more from the simple magnify- 

 ing glass of Van Leeuwenhoek. With the 

 advance of chemistry and of other sciences, 

 all known means of studying minute living 

 things became greatly improved ; and now 

 the idea that many diseases were caused by 

 minute living things was taken up afresh, 

 and carried to triumphant demonstration 

 by a number of medical men and biologists 

 — among the latter by Pasteur, whose re- 

 cent loss is mourned by ■ the world, and 

 whom an eminent American humanitarian 

 sneered at, not many years ago, as an ' ob- 

 scure druggist.' The proof that many dis- 

 eases are caused each by a particular kind of 

 microbe was obtained by vivisection ; for 

 the proof consisted in inoculating animals 

 with the special microbe in question, to the 

 practical exclusion of others, and noting 

 that the animals took the disease, perhaps 

 died of it. As some only of the results of 

 the knowledge thus gained by experiment 

 upon animals, it may be noted that the 

 prevention of cholera has been made more 

 certain, and that great numbers of patients, 

 largely children, have been saved from 

 death by the anti-toxine treatment of diph- 

 theria. But every child thus saved to-day 

 owes his life, not only to medicine, but 

 to biology ; not only to the observations 

 and the vivisections of Klebs and LoefiBer 

 and Koch and Pasteur and others, but to 

 the ' mere scientific curiosity ' of that old 

 lens-polisher of Delft, who spent time in 

 prying into ditch water and particles from 

 the surface of teeth. 



Early in the last century, at a country 



