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haps the most general expression of the scientific conse- 

 quence of his beliefs will be to say that they have made of 

 him in even an unusually strict sense an inductive rather 

 than a deductive inquirer. He has approached natural 

 phenomena, in the most absolute sense of the words, with 

 the simplicity and teachableness of a pupil. When the 

 French Ministry of Agriculture commissioned him in 18G5 

 to study the diseases of the silk-worm, Pasteur, as he declares 

 in the preface to his "Etudes sur la Maladie des Vers a 

 Sole," had never even seen a silk- worm. He mentioned 

 this fact as a reason for declining the commission. " It is all 

 the better" said Dumas, "that you know nothing about 

 the subject; you will liave no ideas upon it except those 

 which result from your own observations." The determin- 

 ing mental conditions in Pasteur's work have been, firstly, a 

 profound sense of the gulf between organic and inorganic 

 matter, and, secondly, what may be most accurately de- 

 scribed as a Christian sense of duty to his neighbours. Tlie 

 first was expressed in his discovery of what he calls molecu- 

 lar dissymmetry, resulting in his formulation of the law that 

 while all inorganic compounds can be superposed, all organic 

 compounds are characterised by what he has graphically 

 symbolised as right and left-handedness. Starting from this 

 basis, the same fundamental principle guided him into a 

 strong opposition of the doctrine of spontaneous generation, 

 and into the famous researches on fermentation which have 

 afforded the sure foundation of the modern developments of 

 the germ theory, of the study of the etiology and rational 

 treatment of zymotic diseases, of antiseptic surgery, and of 

 sanitary science in general. Nor is the second principle less 

 deserving of recognition as a cause of Pasteur's science. 

 Dumas's description of the misery resulting to the rural 

 population of France from the silk-worm disease induced 

 him to undertake those researches on ijehrine and flacherie 

 which resulted in further important confirmations and eluci- 



