IV - PREFACE. 



exotic plants unsuited to the British climate, like other 

 attempts that have repeatedly been made, and have as 

 repeatedly failed, and which no skill in acclimatising will 

 ever render successful, the writer would not have wasted 

 his time by putting pen to paper on so visionary a 

 scheme. 



Those differences of climate which appear to oifer the 

 principal obstacle to the propagation of foreign plants, 

 have but little influence on the naturalization of hemp, 

 especially, in almost every habitable country on the face 

 of the globe. Extremes of latitude are of but little 

 consequence with vegetable productions which come to 

 perfection in a very short interval of time, and at a 

 season of the year which differs but little from the same 

 season in regions far removed. The height of summer 

 offers no great dissimilarity of temperature between the 

 equator and the polar circle ; it is sometimes even hotter 

 high in the north than under the tropics, while the 

 continuity of genial sunshine makes up for the briefness 

 of its entire duration. This singular advantage allows 

 an immense extension to the culture of both flax and 

 hemp ; and they, perhaps, next to wheat, are the plants 

 that have shown the greatest facility to make themselves 

 at home in climates the most opposite. 



Leaving flax to speak for itself, we may remark that 

 hemp is an indispensable necessary to a nation that 

 claims the sovereignty of the seas. ISTo other plant can 

 replace its absence, though several present themselves 

 as useful auxiliaries. But an auxiliary is not a sub- 

 stitute. "We leave undiscussed the question whether 

 E/ussia can better do without coal, than we can without 

 hemp ; that is a point for statesmen and political 

 economists, rather than for agriculturists, to settle. 

 But we do insist upon the fact, that whilst Russia can 



