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SCIENCE. 



[N. S. Vol. II. No. 45. 



whidi was not when he undertook it in a 

 most crude, unsatisfactory condition, and 

 when he left it in its almost perfect form. 

 It was in reaping fruits where others failed, 

 and in perfecting the work which had been 

 begun by less competent scientists, that Pas- 

 teur's merit lies. Others discovered facts, 

 Pastern- determined laws. 



In looking over the life of Pasteur as a 

 whole we are struck forcibly with two char- 

 acteristics. The first was its almost uni- 

 form success. Doubtless Pasteur occasion- 

 ally failed in his experimental work. But 

 of this the world has known nothing for 

 his conclusions seem to have been always 

 correct. So far as Pasteur has appeared 

 before the public from the beginning to the 

 end of his career he has enjoyed an unin- 

 terupted success. The French people have 

 slowly learned to recognize this and finally 

 acquired such a confidence in him that it 

 has been a popular saying which has met 

 all criticisms that ' Pasteur never makes mis- 

 takes.' This unique testimony of public 

 confidence is unexampled, but it seems to 

 have been well deserved, for certainly no 

 scientist has ever held such a position be- 

 fore the public and made so few mistakes. 

 This is the more remarkable when we re- 

 member that he was working in an almost 

 unexplored field. The reason for this uni- 

 form success lies primarily doubtless in the 

 nature of the man ; but not a little of it 

 we may attribute to the fact that in his 

 early training Pasteur was a chemist rather 

 than a biologist. While Pasteur's reputa- 

 tion will rest upon his work in biology he 

 was educated as a chemist, and to this edu- 

 cation we may attribute no little of the 

 uniformity of the success of experiments. 

 The science of biologj' is extremely inexact. 

 Owing to the complicated conditions of life 

 one is ever expecting to find exceptions to 

 the general rules and our scientists have 

 found it utterly impossible to lay down ab- 

 solute definitions or any absolute lines of 



distinction between groups in biological 

 phenomena. The very essence of biologi- 

 cal science is the fact that the phenomena 

 grade into each other. Influenced by this 

 fundamental principle biologists have com- 

 monly fallen into a habit of slackness in 

 dealing with phenomena. Knowing that 

 whatsoever law they maj^ discover will be 

 sure to have its modifications, its varia- 

 tions and its exceptions, they inevitably 

 get into the habit of feeling that an ap- 

 proximation toward accuracy is almost 

 suf&cient. Now the peculiar nature of 

 the field of experimentation in bacteri- 

 ology demands above all things most rigid 

 accuracy. His training as an analytical 

 chemist gave to Pasteur a recognition of 

 the importance of exactness. One who has 

 carried on experiments in molecular phys- 

 ics recognizes that failure is sure to result 

 from inaccuracy, and it was the fact that 

 until he was 30 years of age Pasteur was 

 trained in this kind of accurate experimen- 

 tal manipulation that, when he turned his 

 attention finally to biology and problems 

 connected with the microscopical world, his 

 methods of experimentation and the results 

 of the experiment showed at once a vast 

 advance over those of all of the biologists 

 which had preceded him. For the first 

 time accuracy began to be seen in this field. 

 A second striking feature in Pasteur's 

 life was its dramatic character. One hardly 

 looks for the dramatic in the achievement 

 of scientific results. But Pasteur was a 

 Frenchman, and, although thoroughly mod- 

 est, he was, like other Frenchmen, alive to 

 the advantage of public demonstrations. 

 As we look through his life we can see him 

 taking many and many an opportunity of 

 presenting his scientific results in as dra- 

 matic a style as possible. Meeting with 

 opposition almost constantly during the 

 years of his active investigations, time and 

 time again he planned public tests in which 

 his results should be brought before the 



