^88 [AssEMBtr 



means of their roots or leaves." Nourishing substrnces must there- 

 fore be soluble in water; and if a substance is thus insoluble, it must 

 first be dissolved by the agency of some other substance, and in its 

 new combination become soluble in water, before it is to be consi- 

 dered as nourishment oi* manurie. 



When chemists speak of a rich soil, they mean one which contains 

 a large quantity of humus or organic remains. 



Humus, which, according to Liebig, is the decayed fibre of wood, 

 and is characterized by Thaer as " a mould not properly an earth, 

 but a powdery substance, in a greater or less degree found in the 

 soil." The fruitfulness of the soil depends on its proportions, as 

 likewise it is the only thing in the soil that gives nutriment to plants: 

 it is the remains of vegetable and animal putrefaction. If dry, it is 

 black and powdery; if moist, it has a smooth fatty feeling, and it 

 is different according to the bodies out of which it is formed; but 

 it has certain general peculiarities or properties in which it is essen- 

 tially alike. 



Humus is a form of organic power, a combination of carbon, hy- 

 drogen, nitrogen, and oxygen, and also in less quantities of sulphur, 

 phosphorus, and various salts; it gives nourishment to oiganism: 

 the more life there is, the more humus, the more life. 



For examples in agriculture, we may look to the Chinese; they 

 are known to be the best agriculturists in the world, the best and 

 most scientific gardeners, and the best trainers of plants. Our in- 

 quiry would naturally be, what mamire do they use? Is it the ma- 

 nure from horses? No; they are seldom used by them in agricul- 

 ture. From stall fed cattle? No; the stall feeding of cattle is 

 unknown to them. Human ordure? Yes; and why? Because man 

 eats all varieties of food The excrement of man contains every 

 known requisite to the growth of plants. 



Professor Liebig says, in respect to the quantity of nitrogen con- 

 tained in excrements, 100 parts of the urine of a healthy man, are 

 equal to 1300 parts of the fresh dung of a horse, and to 600 parts 

 of that of a cow. Hence it is evident, that it would be of much 

 importance to agriculture, if none of the human urine were lost. 

 The powerful effect of urine as a manure, is well known in Flanders; 

 but human excrements are considered invaluable by the Chinese, who 

 are the oldest agricultural people we know. Indeed, so much value 



