26 HISTORY OF PHYTOPATHOLOGY 



only by the taxonomic philosophers and medical men 

 but also by the practical gardeners, evidences of whose 

 influence we have already noted in the writings of the 

 previous period. We thus discover during the premodern 

 era two points of view in plant pathology, the philosophic 

 and the practical, clearly marked, at least as far as the 

 writers on the subject are concerned. Not until the 

 middle of the nineteenth century are we to see these two 

 points of view united by Julius Kiihn, the first real plant 

 pathologist who effectively applied the scientific knowl- 

 edge of his day to the practical solution of plant disease 

 problems. 



This period may be said to begin with the presentation 

 in 1705 of a paper by that noted French botanist Joseph 

 Pitton de Toumefort, under the title: Observations on 

 the maladies of plants.' It is worthy of note that 

 Tournefort's classification was the first to present the 

 division of all plant diseases into two great groups, 

 viz., (a) those due to external causes, and (b) those due to 

 internal causes, a division very similar to that em- 

 ployed by some pathologists of more modern times. 

 Tournefort's work on plant pathology has had httle 

 recognition, as his fame rests on his work as a taxonomic 

 botanist. 



Following Tournefort's treatise appeared a number of 

 works on plant diseases, all more or less systematic in 

 character. Among these may be mentioned the following : 



Christian Sigismund Eysfarth," a German, presented 



'Toumefort, J. P. de: Observations sur les maladies des plantes, 

 Mem. Mat. et Phys. tirez des registres .\cad. Roy. Sci. de I'anne 170S- 

 332-345, Paris, 1730. 



^*Eysfarth, Christian Sigismund: Dissertationem physicam de 

 morbis plantarum, pp. 1-48, Lipsiae, 1723. 



