DISEASE OF THE VINE. 239 



condition was wanting — the predisposition to contract a disease. 

 I feel indeed the force of the objections that may be made to my 

 experiments as being made upon too limited a scale, but, however 

 small, still some value must be attached to them. 



The Secretary of Correspondence of our Academy has sug- 

 gested to me that I should try the inoculating grapes already 

 diseased, first removing carefully the mildew which may be upon 

 them. I purpose to take it in hand during my next stay in the 

 country; in the mean time, what I am about to state may supply 

 the place of the experiment, and I think speaks pretty clearly. 

 In a vineyard outside the Porto S. Xiccolo near the walls, I was 

 a few days back examining a Vine covered with grapes in the 

 worst state; the farmer observed to me that they had been medi- 

 cated, and that for a time they had appeared to be cured. I took 

 two grapes and placed them under the microscope : I found on the 

 grapes many crystals of urine mixed with other matter which 

 showed that they had been drugged. But the cryptogam had 

 reappeared as fresh as usual, and as thick as upon the non-medi- 

 cated grapes. I hear that a great number of similar facts might 

 be quoted, and they appear to me to prove two things ; first, the 

 inefficacy of the remedies hitherto used, and secondly, that the 

 evil originates in the grapes themselves, or in other words, in a 

 predisposition to contract disease. 



The authors who have treated of the Oidium Tuckeri as the 

 cause of the disease, admit the predisposition. The same 

 Berenger, speaking of the Erysiphe, says, " Its luxuriant develop- 

 ment (Generatio floccipara) is the true and natural cause of the 

 immense diffusion of the cryptogam, and consequently the imme- 

 diate cause, although not the only one, of the present malady of 

 the Vines ; I say not the only one, because it is uot only probable, 

 but almost certain, that it would not produce that pernicious 

 effect, if a certain number of vines, either by individual constitu- 

 tion, by asthenia, or by some other pathological state, were not in 

 a certain manner predisposed to receive it." 



Now, I ask, if you grant the predisposition, in what consists, 

 what is, this particular anomalous state of the Vine ? If it had 

 been a small vineyard only, or a few plants situated here and 

 there in special localities, it is possible that conditions might be 

 found to account plausibly for the phenomenon. But the ques- 

 tion is that of a most extensive fact, of a disease, which, like an 

 epidemic, has spread successively over the whole of Europe where 

 Vines are cultivated. In this case how can the predisposition be 



