CONTENTS OF PART III. 



Of the forms in which organic matter 

 usually exists in the soil, and the cir 

 cumstances under which its decom- 

 position may take place *..p. 401 



General action of alkaline substances 

 upon organic matler 403 



Special effects of caustic lime upon the 

 several varieties of organic matter in 

 the soil 404 



Action of mild (or carbonate of) lime 

 upon the vegetable matter of the 

 soil 406 



Of the comparative utility of burned and 



unburned lime p. 409 



Action of lime on organic substances 



which contain nitrogen 409 



How these chemical changes directly 



benefit vegetation 412 



Why lime must be kept near the surface.ib. 

 Action of lime upon the inorganic or 



mineral matter of the soil 413 



Action of lime on animal and vegetable 



life 415 



Use of silicate of lime. 416 



LECTURE XVII. 



OF ORGANIC MANURES. 



Of green manuring or the application of 

 vegetable matter in a green state .417 



Important practical results obtained by 

 green manuring 418 



Of the plants which in different soils 

 and climates are employed for green 

 manuring 419 



Will green manuring alone prevent land 

 from becoming exhausted 1 421 



Of the practice of green manuring 422 



Of natural manuring with recent vegeta- 

 ble matter Jb. 



Wei-iht of roots left in the soil by the 

 different grasses and clovers 423 



Improvement of the soil by laying down 

 to grass 424 



Improvement of the soil by the planting 

 of trees 429 



Of the use of sea- weed aa a manure 431 



Of manuring with dry vegetable sub- 

 stances 433 



Use of rape-dust 434 



Use of decayed vegetable matter as a 

 manure 43€ 



Use of charred vegetable matters— soot, 

 &c., as manures 437 



Of the theoretical value of different 

 vegetable substances as manures 440 



LECTURE XVIII. 



ANIMAL MANURES. 



Of flesh, blood, and skin 443 



Of wool, woollen rags, hair, and horn. . ,445 



Of the composition of bones 446 



On what does the fertilizing action of 



bones depend 1 447 



or the application of bone-dust to pas- 

 ture lands 451 



Of animal charcoal, the refuse of the su- 

 gar refineries, and animalized carbon. .4.52 

 Of" fish, fish refuse, whale blubber, and 



oil 453 



Relative fertilizing value of the animal 



manures already described. 454 



Of the droppings of fowls — pigeons' 



dung and guano 456 



Results of experiments with guano 459 



Of liquid animal manures— the urine of 

 man, of the cow, the horse, the 



sheep, and the pig 460 



Of the waste of liquid manure — of urate 

 and of sulphated urine 463 



Of solid animal manures— night soil, 

 the dung of the cow, the horse, the 

 sheep, and the pig 465 



Of the quantity of manure produced 

 from the same kind of food by the 

 horse, the cow, and the sheep 468 



Of the relative fertilizing values of dif- 

 ferent animal excretions 469 



Influence of circumstances on the quali- 

 ty of animal manures 470 



Of the changes which the food under- 

 goes in passing through the bodies of 

 animals '. 472 



Of farm-yard manure, and the loss it un- 

 dergoes by fermenting 474 



Of top-dressing with fermenting ma- 

 nures 477 



Of eating off with sheep 478 



Of the improvement of the soil by irri- 

 gation 479 



