THE MILLARDETIAN PERIOD 63 



fungicide, bordeaux mixture; (b) governmental espousal 

 of the science, and (c) discovery of the bacterial nature of 

 some of our most destructive plant diseases combined 

 to initiate a new epoch in the history of plant pathology. 



A clear and comprehensive view of this period may 

 best be obtained, perhaps, by a brief consideration, 

 first, of the epoch-making discoveries and the men who 

 made them, and, second, of the life and works of those 

 phytopathologists who largely dominated the thought 

 and teaching of the time. 



The discovery of bordeaux mixture, as already pointed 

 out, was the most potent factor in the development of the 

 economic phase of plant pathology. It gave to the plant 

 pathologist a means of control of wide application and 

 remarkable efficiency. It became the universal fungicide. 

 The active principle of this fungicide is copper. Numer- 

 ous other copper fungicides were rapidly devised and 

 exploited, such as ammonium copper carbonate, soda 

 bordeaux, and eau celeste, but none of these were found 

 to compare, in safety to the plants and in effectiveness 

 against the fungi, with the bordeaux mixture originally 

 devised by Millardet. As regards the control of plant 

 diseases, this may well be regarded as the "copper" 

 period. Of the man who first properly appreciated the 

 fungicidal value of the copper salts, a few words are now 

 in place. 



Pierre Marie Alexis Millardet was born December 13 r 

 1838, at Montmerey-la-ville in the department of Jura, 

 and died December 15, 1902. Born of intellectual 

 parents of old and honorable families, he was well taught 

 and educated. He first studied medicine, but soon 

 abandoned it for the more enticing pursuit of botany. 



