I. TO HAMPSTEAD. 13 



Some rivers are extremely rapid in their 

 course, while the clear and peaceful waters 

 of others flow with an almost imperceptible 

 motion. 



Animals, likewise, as you know, differ in 

 their appearance, size, and shape, as well 

 -as in their external covering $ and it is from 

 this difference of structure, that naturalists 

 were first led to arrange the animal kingdom 

 into classes, orders, genera, and species ; an 

 arrangement which greatly facilitates the stu- 

 dy of zoology. In the same manner we are 

 struck, at the first glance, with the various 

 forms and colors of vegetables. Herbs, 

 shrubs, and trees, are so distinct, notwith- 

 standing the analogy of their nature, that 

 the early botanists classed them' separately. 

 In this, as in every thing else, nature seems 

 to have had the comfort of man in view. 

 Yon iire sufficiently acquainted with the 

 difference which exists between the stems of 

 herbs and trees : those of the former are 

 herbaceous, soft, and flexible j while those 



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