24 



" He said, that it would probably be in the recollection 

 of the society, that he had the honour of laying before it 

 in the session of 1845, an account of the first year's progress 

 of that singular disease in the potato plant, by which some, 

 millions of the population have been suddenly deprived of their 

 accustomed food. Contrary to the sanguine hopes of many 

 persons, the disease has not only continued to exist, but had 

 this year raged with increased violence. The subject was one of 

 so much curiosity, as a botanical question, and one of so much 

 interest in its bearings on the agriculture and commerce of 

 the country, as well as on the habits and employments of the 

 people, that he felt sure that he should receive the kind atten- 

 tion of the society whilst he brought before it the principal 

 facts connected with the present year's manifestation of the 

 disease. 



"It would be in the recollection of the members of the 

 society that the spring, summer, and autumn months of last 

 year — 1845 — were unusually cold and wet, and that the 

 excessive wetness of the season, after midsummer, the want 

 of solar heat during the whole season, and the sudden 

 chauges of temperature in the mouth of July, were then 

 regarded as the principal causes of this disease. It would 

 also be remembered that the spring and early part of the 

 summer of the present year — 1846 — were unusually hot and 

 dry, and that, though abundant rain fell afterwards, unusual 

 heat was the characteristic of the present season. The two 

 seasons had thus been as different as possible, and the con- 

 tinuance of the disease, under circumstances so opposite, 

 strengthened the opinion, that it was not altogether owing to 

 seasonal causes, but arose from some other cause more perma- 

 nent and more deeply seated. The potato was found to flourish 

 in its natural state in the Chunos Islands, where it was 

 seldom fair, and on the arid plains of Peru, where it never 

 rained ; and in its cultivated state, it had survived many 



