Iron. — Iron is a metallic element, always present in plants, and 

 entering into the composition of blood corpuscles, etc. 



Lecithin. — Lecithin is a body somewhat resembling fat, though it 

 contains both nitrogen and phosphorus. 



LiGNiN.— Lignin is a substance probaljly of an acid character which 

 united with cellulose forms the hard woody pai't of the plant. 

 In itself it is of little or no nutrient value, being almost 

 wholly indigestible, and furthermore, it prevents to a cousid- 

 erable degree the digestion of other constituents, especially 

 cellulose. 



Lime. — Lime is a valuable component of plant ashes, being always 

 present. It is one of the chief constituents of bone. 



JNIagnesia. — INIagnesia is an inorganic substance, somewhat resem- 

 bling lime, always present in plants. 



Manganese. — INIanganese is a comparatively rare inorganic element, 

 of which traces are occasionally found in plants. 



Nitrates. — By nitrate is meant a combination of nitric acid with a 

 so-call. d base such as soda or potash. Thus nitrate of soda 

 or nitrate of potash are spoken of as nitrates. 



Nitric Acid. — Tliis is one of the most impcntant of the inorganic or 

 mineral acids and is a combination of hydrogen, oxygen and 

 nitrogen. Jt is present in all field and garilen crops, being 

 especially noticeable in beets, turnii)s,and the like. Nitrogen 

 enters the plant through the roots chit fly in this form. 



Nitrogen. — Nitrogen in its natural state is an ineit gas. It exists 

 however, combined with a variety of other elements. It is 

 the characteristic element of the albuminoids as well as of 

 nitric acid and ammonia. 



Nitrogen-Free Extract. — Nitrogen-free extract includes all the 

 organic nitrogen-free compounds of feed stuffs, — except crude 

 fibre and the ether extract group, — such as cane and grape 

 sugars, starch, dextrin, gum, lignin, coloring matter, organic 

 acids, etc. 



Of these various substances, the sugar, dextrin, starch, 

 gums, have the same nutritive effect, so far as digestible, the 

 others being of an inferior value. 



As a nutrient, nitrogen-free extract produces heat and 

 energy, serves as an albuminoid economizer, and an excess is 

 transformed into fatty tissues. 



Nutrients. — A nutrient is any digestible food constituent which 

 builds up the body or repairs its wastes, produces heat for 

 bodily warmth or energy for carrying on its processes. 



The four great groups of nutrients are ash, protein, fat, and 

 carbohydrates. 



