supplement. SCIENCE AND ART OF AGRICULTURE. 



1299 



II. Table showing the Composition of the Ashes of our most frequently cultivated Crops. 



and other Authorities. 



From Saussure 



Wheat {££ 



Oat grain 

 Barley grain 

 Vetches - 

 Turnips - 

 Potatoes - 



III. Table showing the Quantity of Alkali associated with the various Minerals entering into the Con- 

 stitution of Soil. From Liebig. 



Analysis has proved the existence of more or less potass in all clays, as also in marls. From this table 

 it would appear that by far the best soil would be that originating from the disintegration of felspar ; and 

 we think that observation will often prove this to be the case. 



BOOK II. 



THE ANIMAL KINGDOM WITH REFERENCE TO AGRICULTURE, (p. 281.) 



6. — 1836. Animals, according to Liebig. are subject to the action of two powers which are cori- 

 lv at work: vitality, which is the cause of life ; and chemical affinity, which is the cause of death. 



8116. 

 stantly at work: vitality, .. 



The o'hject of vitality is to sustain and increase the mass of the body in which it resides ; the object of 

 the chemical forces is to destroy and waste that body. Vitality resides iu every part of the fortress 

 which it has to defend ; the chemical forces are encamped in the atmosphere which everywhere sur- 

 rounds it. In fact, the chemical power is the gas oxygen, one of the principal constituents of common 

 air ; and its affinity for the elements of organic matter is so great, that it constantly endeavours to destroy 

 it. The whole life of an animal consists in a conflict of these rival powers ; in the endeavour of vitality 

 to sustain and increase ; in that of chemical affinity to waste and destroy. In health, vitality possesses 

 the ascendancy, and modifies the destructive efforts of the chemical powers. Disease, on the other hand, 

 is a temporary conquest of the chemical over the vital forces ; while death is the victory of the former, 

 and annihilation of the latter." (Journ. JR. A.S. E.,vo\. iv. p. 221.) 



81 17. — 1963. The food of all animals, and particularly of those employed in agriculture, Liebig lias 

 shown to consist of two elementary substances: gluten or albumen, composed of carbon, hydrogen, ni- 

 trogen, and oxvgen, which constitute the nutriment of the body; and starch, sugar, gum, and other 

 substances containing carbon, hvdrogen, and oxvgen, but from which the element nitrogen is absent. 

 It is onlv the substances containing nitrogen, or which in other words are azotised, which produce flesh, 

 while the other elements are for the production of heat bv the combustion of carbon m consequence of 

 its union with oxvgen. The heat generated in this combustion in the body of an animal, is exactly 

 equivalent to that produced bv burning the s.'.rne amount of carbon in a fire or a candle. As the heat 



40 2 



