294 IMPROVEMENT OF THE SOIL 



uhle organic matter. Liebig appeals to this example to prove 

 that plants will grow without humus ! 



8. Pigeon dung and that from domestic fowls is similar 

 to guano. The former has been proved by experiment to 

 be f stronger than horse dung. The manure of fowls has 

 been applied with the best effects to peach trees, vines and 

 other plants, which after a few years present the most luxuri- 

 ant and healthy appearance. It may be applied by mixing 

 one part of manure with 8 or 10 of water, and put around 

 the roots. 



II. Animal bodies, such as flesh, skin, gristle, sinews 

 and bones, form by decomposition most powerful manures. 

 They produce much larger quantities of ammonia than fer- 

 menting dung heaps, and are much richer in salts, contain- 

 ing in fact all the substances which are necessary to sup- 

 port the vegetable organs. The following table shows the 

 composition of animal bodies. 



{Sulphate and phosphate of lime, 

 Phosphates of soda, magnesia and ammonia, 

 Sulphate and muriate of potash and soda. 

 Carbonates of potash, soda, lime and magnesia. 



V ♦ Ki C Benzoate, ^ 



vegeiaDie i Acetate, \ Of potash, soda, lime. 

 ^^^^^- ^Oxalate, ^ 



Animal C Urate of ammonia. 

 Salts. \ Lactate of ammonia. • 



Oxides of iron, manganese and silica. 



Animals and vegetables contain several substances, which 

 appear to be identical. Gluten, vegetable fibrin, albumen 

 and legumin, are vegetable principles, and the correspond- 

 ing substances in animals are fibrin, albumen and casein. 

 The last two are identical in composition with vegetable al- 

 bumen and legumin. These principles are combined with 

 alkalies, earths, sulphur and phosphoric acid. When de- 

 prived of their inorganic portions, they have been referred to 

 a single organic principle, called protein, which is thus con- 

 stituted. 



