28 



A DISCOURSE 



BOOK I. water, be it of rain or the river, (superior or inferior,) carries with it a 

 certain superfine terrestrial matter, not destitute of vegetative particles, 

 which gives body, substance, and all other requisites to the growth and 

 perfection of the plant, with the aid of that due heat which gives life 

 and motion to the vehicle's passage through all the parts of the vegetable, 

 continually ascending, till (having sufficiently saturated them) it trans- 

 hyacinth, and other bulbous roots, are known to perfect their flowers in pure water. — 

 Hence superficial observers have drawn an argument in favour of water being the food of 

 vegetables. But the truth is, the roots, stem, and flowers of such plants are nourished by 

 the mucilaginous juices of the bulb, diluted by the surrounding water. This mucilage is 

 just sufficient to perfect the flower — and no more. Such a bulb neither forms seeds, nor 

 sends forth ofF-sets. At the end of the season, it appears weak, shrivelled, and exhausted, 

 and is rendered unfit to produce flowers the succeeding year. A root of the same kind, 

 that has been fed by the oily and mucilaginous juices of the earth, essentially differs in 

 every particular : it has a plump appearance, is full of mucilage — with ofF-sets upon its 

 sides. All rich soils, in a state of nature, contain oil ; and in those lands which have been 

 under the plough for some years, it is found in proportion to the quantity of putrid dung that 

 has been laid upon them, making an allowance for the crops they have sustained. To set 

 this matter in a clearer light, let us attend to the effects of manures of an oily nature, and 

 we shall soon be satisfied that oil, however modified, is one of the chief things concerned 

 in vegetation. Rape-dust, when laid upon land, is a speedy and certain manure, though 

 an expensive one, and will generally answer best on a limestone land, or where the soil 

 has been moderately limed. This species of manure is much esteemed by the farmer. It 

 contains the food of plants ready prepared ; but as it is not capable of loosening the soil by 

 any fermentation, the lands upon which it is laid ought to be in excellent tilth. At present, 

 that useful article of husbandry is much diminished in goodness, owing to the improved 

 methods of extracting the oil from the rape. Heat and pressure are employed in a double 

 decree. Farmers that live in the neiffhbourhood of laree towns use abundance of soot. 

 It is an oily manure, but different from the former, containing alkaline salt in its own 

 nature, calculated as well for opening the soil, as for rendering the oily parts miscible 

 with water. It is observed that pigeon's dung is a rich and hasty manure. These 

 animals feed chiefly upon grains and oily seeds ; it must therefore be expected that their 

 dung should contain a large proportion of oil. The dung of stable-kept horses is also a 

 strong manure, and should not be used until it has undergone the putrid ferme.nl, in order 

 to mix and assimilate its oily, watery, and saline parts. Beans, oats, and hay, contain 

 much oil. The dung of horses that are kept upon green herbage, is of a weaker kind, 

 containing much less oil. Swine's dung is of a saponaceous and oily nature, and perhaps 

 is the richest of the animal manures. When made into a compost and applied with judg- 

 ment, it is excellent both for arable and grass lands. The dung of stall-fed oxen, espe- 

 cially if oil-cake make part of their food, is of a rich quality, and greatly preferable to that 

 of cows and oxen supported by grass only. A farmer, when he purchases dung, should 

 attend to all the circumstances under which it is produced. One load of dung from a 

 hunting stable where much corn is consumed, is worth two loads produced by hay and 



