GRE 



276 



GRO 



ent, — the chief constituent of all plants, 

 carbon, — from the atmosphere : they, 

 therefore, return to the soil more de- 

 composing matter than they have taken 

 from it. 



The putrefaction of the vegetables, 

 and the gases in that case emitted, says 

 my brother, Mr. Cuthbert Johnson, 

 " appear to be on all occasions highly 

 invigorating and nourishing to the suc- 

 ceeding crop. During this operation, 

 the presence of water is essentially ne- 

 cessary, and is most probably decom- 

 posed. The gases produced vary in 

 different plants ; those which contain 

 gluten emit ammonia ; onions and a few 

 others evolve phosphorus ; hydrogen, 

 carbonic acid gas, and carburetted hy- 

 drogen gas, with various vegetable 

 matters, are almost always abundantly 

 formed. All these gases when mixed 

 with the soil are very nourishing to the 

 plants growing upon it. The observa- 

 tions of the farmer assure us that they 

 are so. He tells us that all green ma- 

 nures cannot be employed in too fresh 

 a state, that the best corn is grown 

 where the richest turf has preceded it, 

 and that where there is a good produce 

 of red clover there will assuredly follow 

 an excellent crop of wheat ; he finds 

 also that when he ploughs in his crop of 

 buckwheat to enrich his land, that this 

 is most advantageously done when the 

 plant is coming into flower." — Farm. 

 Encyc. 



Sea Weed is a species of green ma- 

 nure, for it ought to be employed 

 whilst quite fresh. There are many 

 species, and they differ very essentially 

 in their components. The LnurinariiB , 

 those long, tawny-green, ribbon-like 

 algae so common on our coasts, contain 

 besides vegetable matter a large pro- 

 portion of the salts of potash in addition 

 to those of soda ; whereas the Fuci con- 

 tain none of the salts of potash. All, 



The advantage of green manure is 

 practically understood by thousands of 

 our farmers, who, though they may be 

 unable to philosophize upon the subject 

 or refer to its true chemical cause, fully 

 appreciate its value. 



The great desideratum of those who 

 aim at enriching the soil, is to produce 

 clover, — that attained, the rest is easy. 

 Clover, when turned in, prepares the 

 land for every description of crop, and 

 places the whole under the control of 

 the husbandman. 



GREVILLEA. Forty-two species. 

 Green-house evergreen shrubs. Ripe 

 cuttings, and some species, seeds. 

 Sand, loam and peat. 



GRIFFINIA. Three species. Stove 

 bulbous perennials. Offsets. Seeds. 

 Turfy loam, white sand and peat. 



GRINDELIA. Nine species. Chiefly 

 green-house evergreen shrubs. G. an- 

 gustifolia and G. squamosa are herba- 

 ceous perennials, and G. ciliata a hardy 

 annual. Cuttings. Loam and peat. 



GRISLEA. Two species. Stove 

 evergreen shrubs. Cuttings. Sandy 

 peat and loam. 



GROBYA AmhersticE. Stove orchid. 

 Division. Wood. 



GROTTO, is a resting place, formed 

 rudely of rock-work, roots of trees, 

 and shells, and is most appropriately 

 placed beneath the deep shade of woods, 

 and on the margin of water. Its inten- 

 tion is to be a cool retreat during sum- 

 mer. 



GROUND CHERRY. Cerasus Cha- 

 mcEcerasus. 



GROUND CHRISTA. Cassia Cha- 

 mmchrista. 



GROUND CISTUS. Rhododendron 

 Chamdcistus. 



GROVE, is a moderately extensive as- 

 sociation of trees without underwood. 



" The character of a grove is beauty ; 

 for fine trees are lovely objects, and a 



however, are excellent manures, and I J grove is an assemblage of them, in 



know a garden, near Southampton, very 

 productive, tliat for some years has had 

 no other manure. It is particularly 

 good as a manure for potatoes. The 

 Fucus vesiculosus, so distinguishable by 

 the bladders full of air embedded in its 



which every individual retains much of 

 its own peculiar elegance, and whatever 

 it loses is transferred to the superior 

 beauty of the whole. To a grove, 

 therefore, which admits of endless vari- 

 ety in the disposition of the trees, differ- 



leaves, is a very excellent manure. It encesin their shapesand theirgreensare 

 contains, when dry, about 84 parts ve- i seldom very important, and sometimes 

 getable matter, 13 parts sulphate of ' they are detrimental. Strong contrasts 

 lime and magnesia, with a little plios- , scatter trees which are thinly planted, 

 phate of lime, and 3 parts sulphate and j and which have not the connexion of 

 muriate of soda. I underwood ; they no longer form one 



