INTRODUCTION. 7 



condition of mankind which have such powerful 

 effects upon the advance of the world in knowledge 

 and happiness. In this point of view, a blade of 

 wheat, a potato, or a peppercorn, may each be made 

 a theme to direct the attention to some of the most 

 important causes of the prosperity of nations ; and the 

 result of such observation and inquiry must necessarily 

 be a conviction, that all human interests are strictly 

 allied, and that the great mutual necessities which 

 bind mankind together are steadily going forward to 

 break down the barriers which separate classes and 

 nations, and to diffuse knowledge, and plenty the fruit 

 of knowledge, over all the earth. 



In the study, then, of this subject, all who are en- 

 gaged in the culture of the soil, whether the wealthy 

 proprietor who draws from his estates a lordly re- 

 venue, the farmer who earns from his fields an 

 independent subsistence, or the peasant whose toil 

 obtains from the little nook which joins his cottage 

 a wholesome meal for his family, may draw from the 

 pursuit the means of mental improvement. Those, 

 too, whose callings or professions shut them out 

 from the contemplation of rural objects, may derive 

 both pleasure and advantage from knowing by what 

 care a grain of wheat is elaborated into the material 

 of a loaf of bread, and how that loaf is supplied 

 with regularity both at seed-tiine and at harvest. 

 Lastly, each and all may, with equal profit, acquire 

 some information concerning that almost countless 

 number of foreign productions, which commerce has 

 brought to form a part of the daily food and comfort 

 of almost the humblest of our fellow-citizens. Does 

 it not in fact appear natural, it might almost be said 

 inevitable, that every one should feel an interest in 

 prosecuting inquiries as to things to which he is in- 

 debted for so many of his daily comforts and enjoy- 



