THE LEAF. 31 



proportion to their bulk, and why is it so ? What soil does 

 it like, and what properties does it acquire from it ? The en- 

 deavour to answer these questions will soon lead you to a 

 rational inquiry into the plant's history. You will first ascer- 

 tain what rock or earth it delights in, and what climate and 

 circumstances ; then you will see how its root is fitted to sus- 

 tain it mechanically under given pressures and violences, and 

 to find for it the necessary sustenance under given difficulties 

 of famine or drought. Lastly you will consider what chemi- 

 cal actions appear to be going on in the root, or its store ; 

 what processes there are, and elements, which give pungency 

 to the radish, flavour to the onion, or sweetness to the liquor- 

 ice ; and of what service each root may be made capable 

 under cultivation, and by proper subsequent treatment, either 

 to animals or men. 



18. I shall not attempt to do any of this for you ; I assume, 

 in giving this advice, that you wish to pursue the science of 

 botany as your chief study ; I have only broken moments for 

 it, snatched from my chief occupations, and I have done noth- 

 ing myself of all this I tell you to do. But so far as you can 

 work in this manner, even if you only ascertain the history of 

 one plant, so that you know that accurately, you will have 

 helped to lay the foundation of a true science of botany, from 

 which the mass of useless nomenclature,* now mistaken for 

 science, will fall away, as the husk of a poppy falls from the 

 bursting flower. 



CHAPTER III. 



THE LEAF. 



1. IN the first of the poems of which the English Govern- 

 ment has appointed a portion to be sung every day for the in- 



* The only use of a great part of our existing nomenclature is to en- 

 able one botanist to describe to another a plant which the other has not 

 seen. When the science becomes approximately perfect, all known 

 plants will be properly figured, so that nobody need describe them ; and 

 unknown plants be so rare that nobody will care to learn a new and dif- 

 ficult language, in order to be able to give an account of what in all 

 probability he will never see. 



