ORGANIC AND INORGANIC MATTER. 21 



— their mode of growth — and the manner in which their fooa is ab- 

 sorbed, changed, and converted into parts of their substance. 



III. The origin, nature, and principal differences of soils — with the 

 circumstances on wbich their relative fertility depends, or under which 

 it is modified. 



IV. The nature and differences of manures, and their mode of action, 

 whether directly in supplying food to the plant, or indirectly in hasten- 

 ing and increasing their growth. 



V. The nature and diversities of the food raised as the result of cul- 

 ture — especially in reference to their several equivalents or powers of 

 supporting animal life. 



Under this head the feeding of cattle and the variations in the quan- 

 tity and quality of dairy produce, will form subjects of consideration. 



These different branches, I believe, comprehend the whole subject 

 of chemical agriculture ; in regard to all of them we shall derive either 

 from chemistry or geology much important information. 



§ 1. Different kinds and states of matter. 



All the forms of matter which present themselves to our view, 

 whether in the solid crust of the globe on which we live, in the air 

 which forms the atmosphere by which we are surrounded, or in the bo- 

 dies of animals and plants — all are capable of being divided into the two 

 great groups of organic and inorganic matter. The solid rocks and soils, " 

 the atmosphere, tlie waters of the seas and oceans, every thing which 

 neither is nor has been the seat of life, may generally be included under 

 the head of inorganic matter. The bodies of all living animals and 

 plants, and their dead carcases, consist of organic or organized matter. 

 These generally exhibit a kind of structure readily visible by the eye, 

 as in the pores of wood, and in the fibres of hemp, or of the lean of 

 beef,* and are thus readily distinguished from inorganic matter, in 

 which no such structure is observable. 



But in many substances of organic origin also, no structure is obser- 

 vable. Thus, sugar, starch, and gum, are formed in plants in great 

 abundance, and yet do not present any pores or fibres ; they have never 

 been endowed with organs, yet being produced by the agency of living 

 organs, they are included under the general name of organic matter. 

 So when animals and plants die, their bodies undergo decay, but the 

 matter of which they are composed is considered as of organic origin, 

 not only as long as any traces of structure are observable, but even after 

 all such traces have disappeared. Thus coal is a substance of organic 

 origin, though almost all traces of the vegetable matter from which it 

 lias been derived, have been lojig ago obliterated. 



Again, heat chars and destroys wood, starch, and gum, forming black 

 substances totally unlike the original matter acted upon. By distillation, 

 wood yields tar and vinegar ; and by fermentation, sugar is converted 

 first into alcohol, and then into vine^r. All substances derived from 

 vegetable or animal products by these and similar processes are included 

 under the general designation of organic bodies. 



* The pores of wood and fibres and minute vessels in animals being the organt or instru. 

 meats of hfe, the substances themselves are called organized or organic. 



2 



