PREFACE. Til 



logic incessantly at work upon any opinion which he desired 

 to force into the public mind. 



Amongst the manifold imperfections incidental to a 

 first volume, one omission may demand a special expla- 

 nation. In a -work, which it is desired to make, as 

 strictly as possible, a record of practical suggestions 

 and well-estabhshed principles, it has been deemed pre- 

 matm*e to introduce extracts from the many interesting 

 and elaborate dissertations and notices which have 

 appeared on the subject of the Potato Disease. The 

 theory has yet to be constructed which shall compre- 

 hend and account for all the phenomena of that singular 

 vegetable calamity. In the mean time, a patient accumu- 

 lation of facts bearing upon the subject is the work to 

 be done; and the Rej^ort of the Highland and Agri^ 

 culhiral Society of Scotland on the Potato Disease, 

 presents an instryctive example of the kind of investi- 

 gation that is needed. Extensive, however, as has been 

 the field of this inquiry, and carefully as it appears to 

 have been searched, the Rejjort declares that "no satis- 

 factory explanation of the predisposing causes of this 

 destructive disease has yet been given; and that, of the 

 theories promulgated on the subject, none seems calcu- 

 lated to lead to a practical conclusion." ^ 



To the Editors of the several Journals who have so 

 kindly and liberally permitted the Editor of tliis Book 

 to avail himself of their respective pubhcations, he begs 



' See Transaction.1 of the Highland and Agricultural Society of 

 Scot land.— October 184G. 



