174 \MMALS AND IT, A NTS 



v i 



of the food of the bean. lint. the weights of MM 



carbon, hydrogen, oxygen, nitrogen, phosphorus, 



Sulphur, and other elementary bodies contained in 

 the bean-plant, and in the Heeds which it produces, 

 are exactly equivalent to the weights of the RDM 

 elements which have disappeared from the 

 materials supplied to the bean during its growth. 

 Whence it follows that the bean has taken in only 

 the raw materials of its fabric, and has maim 

 faetured them into bean -stuffs. 



The bean has been able to perform this gn-at 

 chemical feat by the help of its green colouring 

 matter, or chlorophyll ; for it is only the given 

 parts of the plant which, under the influence of 

 sunlight, have the marvellous power of decom 

 posing Carbonic ;ieid, sett, ing free? the oxygen and 

 laying hold Of the carbon \\hich it contains. In 

 fact, the bean &quot;1. tains two of the absolutely in 

 dispensable elements of its substance fVom I. wo 

 di -I met sources ; the watery solution, in which it 

 roots are plunged, contains nitrogen but no carbon ; 

 the air, to which tin- leaves are exposed, contains 



carbon, but its nitrogen is in the state ,,r a free 



gas, in which condition the b.-.-m c;m m.-ike DO 



Of it;- 1 and the chlorophyll&quot; is the af.pai at us by 



1 I piii) DM th.-it tin- ;iir \\itli \\liidi the bean i 



supplied in tin- MM st:itril contains no anniioiiiaf:, il Halts. 



a Tin- r-i-i-nt IMeftrohet of I lin^slicim liavi- i-aiscd a lio.st of 



rto tin- exact slian- taken l.y liloiopliyll in tin- 

 ini- 



ini-al opcr.-itiuns \vliidi aiv ctl c. (.-.! l,y tin- ^n--n jarts of 

 ]lant.s. It may ! that tin- chloioj.liyll is only a constant con 

 comitant of tlie actual deoxidising apparatus. 



