284 MASSACHUSETTS AGRICULTURE. 



the remote cause of it. We may be able to guess at some of 

 the proximate causes — such as high manuring and general 

 luxurious treatment; (for after the predisposition to disease is 

 created in any subject, a thousand different agents may act as 

 proximate or exciting causes of its development,) while its 

 remote cause still remains hidden. The potato disease probably 

 resembles certain diseases of the animal system, whose origin is 

 involved in mystery, whose nature is but partially understood, 

 and whose remedies serve rather to assuage than to cure them. 

 Such diseases may come upon an individual, in spite of the 

 most rational employment of those measures of prevention 

 which usually render one secure from its attacks. Still, experi- 

 ence has proved that the precautionary measures recommended 

 by physicians are general safeguards ; and that the disease, 

 whatever it may be, will attack a smaller proportion of those 

 who attend to these sanitary rules than of those who neglect 

 them. 



The same course of reasoning will apply to the potato disease. 

 This plant, without doubt, will always be liable to its attacks ; 

 but careful inductive experiment, carried through a conside- 

 rable series of years, may bring to light certain facts, upon 

 which a system of sanitary rules may be established ; and by 

 attending to #iese rules in the cultivation of the potato, we 

 may thereby obtain, on the average, more abundant and more 

 healthy crops than we could if these rules were neglected. We 

 may learn the different effects of a wet and a dry soil, of a new 

 and an old soil, of a rich and a mean soil ; of a warm 

 and a cold situation, of the north and the south side of a 

 declivity ; and of many other conditions, which it is needless 

 to enumerate, since they could be multiplied to infinity. 



Many facts of important signification have already been 

 ascertained by the experience of intelligent cultivators, showing 

 that certain modes of tillage lessen the ravages of the infection 

 and reduce its chances of recurrence. Each of these facts 

 constitute one step in our progress towards the great point to 

 be attained. Still it seems to me that this agricultural problem 

 will be found to resemble those mathematical problems by every 

 process of which we approximate nearer to the desired result, 

 but can never fully read it. Though we may never ascertain 

 the true character of the potato disease, nor learn the means by 



