HOW PLANTS DBINK. 



61 



'starches, oils, sugars, and so forth, all of which 

 contain a littlc^oxygerjL, but far less than the 

 amount containcHTnthe carbonic acid and water 

 from which they are manufactured. These use- 

 :ul materials, however, though possessing energy, 

 ihat is to say the power^f-prddufijag light and\ / 

 jeat^ and motion, are not exactly livc^ stuffs ; fa 

 n orfleyKPPSRtairi^c^^ 



1 Jsrtuff of all tSBies, animal or vegetable?) proto- 

 plasm, we must have a four lit. dement, \rntr on en ;\ 

 ind that element is supplied by tTiefTrlB r m* 

 ;olution. 



^o now you see the full importance of the\ 



" " K fc e ^ s an< ^ s * arcnes manu - / 



lactured in 'the '"^g|ivea\that mysterious body, r 

 nitrogen, which isnecessary' Th"*^r3er to turn \ 

 these'tmngsmtQ protoplasm and chlorophyll. T > 



A i'ew offier" things besides nitrogen are also 

 needed by the plant from the soil ; the most 

 important of these are apljlnrr and pfcosjgfcprns. 

 The plant, however, does not take in these 

 substances in their free or simple form, as 

 nitrogen, sulphur, and phosphorus, but in com- 

 position, as soluble , nitrates, sulphates, and 

 phosphates. 



Now, I am not going to trouble you with a. 

 long chemical account of how the plant combines, 

 these various materials a thing about which 

 even chemists and botanists themselves know as 

 yet but very little. It will be enough to say 

 here that the \planti builds them up at last into f 

 .ex body, called protoplasm ; f 



an extremely co? 



