AUSTRALASIAN BEE MANUAL 157 



SACCHARINE MATTER OF PLANTS NOT DERIVED FROM 

 THE SOIL. 



Liebig, when describing the chemical processes con- 

 nected with the nutrition of plants, informs us (at 

 page 4*) that — 



There are two great classes into which all vegetable pro- 

 ducts may be arranged. The first of these contains nitrogen ; 

 in the last this element is absent. The compounds destitute 

 of nitrogen may be divided into those in which oxygen forms 

 a constituent (starch, lignine, etc.) and those into which it 

 does not enter (oils of turpentine, lemon, etc.). 



And, at page 141, that — 



Sugar and starch do not contain nitrogen ; they exist in 

 the plants in a free state, and are never combined with salts 

 or with alkaline bases. They are compounds formed from 

 the carbon of the carbonic acid and the elements of water 

 (oxygen and hydrogen). 



Sir Humphrey Davy had already stated that, 

 " according to the latest experiments of Gay Lussac 

 and Thenard, sugar consists of 42*47 per cent, of carbon 

 and 57'23 per cent, of water and its constituents." 

 Now, Liebig in several parts of his work shows that 

 the carbon in sugar and all vegetable products is 

 obtained from carbonic acid in the atmosphere ; and that 

 " plants do not exhaust the carbon of the soil in the 

 normal condition of their growth ; on the contrary, they 

 add to its quantity." 



DERIVED FROM THE ATMOSPHERE AND RAIN-WATER. 



The same authority shows that the oxygen and hydro- 

 gen in these products are derived from the atmosphere 

 and from rain-water ; and that it is only the products 

 containing nitrogen (such as gluten or albumen in the 

 seeds or grains), and those containing mineral matter 



* The edition to which reference is made is the fourth, 

 published in 1847. 



