no PLANT PRODUCTS 



the groups alluded to, but immature plants will often have 

 some nitrogen in unknown combinations. 



For the production of proteins in the plants it is necessary 

 to supply nitrogen, phosphorus, and sulphur. The other 

 plant products which do not contain those elements, are 

 indirectly dependent upon the proteins, and the production 

 of full quantities of starch or sugar cannot be obtained without 

 adequate supplies of fertilizing ingredients containing those 

 elements. 



The waste of solar energy alluded to in Table 18 shows 

 that much of the energy of the sun is expended in evaporating 

 water. Experiments, both on the small and on the large 

 scale, show that the proper utilization- of fertilizers results 

 in economy in use of water (see p. 101). Phosphates 

 and nitrates appear to be particularly valuable in this respect. 

 The use of top dressings of nitrate of soda or sulphate of 

 ammonia during the droughty periods on corn and hay 

 crops is a very well-known practice, whilst the use of 

 phosphatic manures, either directly or indirectly, during 

 the stimulus of root development also produces an economy 

 of water. The question of the water supply to the plant is, 

 therefore, very closely bound up with the supply of proper 

 fertilizing ingredients, and much can be done in dry regions 

 or during dry periods to economize the water supply by a 

 liberal use of phosphatic and nitrogenous fertilizers. 



REFERENCES TO SECTION I 



Haas and Hill, " Chemistry of Plant Products," p. 143. (Longmans.) 



Fenton, Journ. Chem. Soc., 1907, T. p. 687. 



Borday, Proc. Roy. Soc., 1874, p. 171. 



Warner, Proc. Roy. Soc., 1914, B. 87, p. 378. 



Dyer, Journ. Chem. Soc., 1894, T. 115. 



Cross and Beavan, " Cellulose." (Longmans & Co.) 



Forster, " Bacterial and Enzyme Chemistry." (Arnold.) 



Armstrong, " The Simple Carbohydrates ; Monograph on Bio-chemistry." 

 (Longmans.) 



Rideal, " Practical Organic Chemistry." (Lewis.) 



Barnes, "The After Ripening of Cane," Agric. Journ. Ind., 1917, 

 p. 200. 



Bayliss, "The Nature of Enzyme Action." (Longmans.) 



Jorgensen and Stiles, "Carbon Assimilation." (Wesley.) 



