400 Horticultural Chemistry. 



One thing we should insist on, if we were able to keep a proper 

 garden establishment, viz. large succulent cabbage lettuces, 

 brought to table every day during the winter season ; another 

 thing is, all early forcing conducted in pits; a third, the en-, 

 tire disuse of flues, and the substitution of dung, leaves, tan, 

 or hot water ; and a fourth practice, the covering of all descrip- 

 tions of glass frames or roofs in the kitchen-garden with straw 

 or reed mats. 



Art. II. Outlines of Horticultural Chemistry: — Manures. 

 By G. W. Johnston, Esq. of Great Totham, Essex. 



(Continued from p. 272.) 



I shall now proceed to consider manures : a class of 

 bodies of the first importance to the cultivator of the soil, yet 

 of the economy of which he is generally most ignorant, inas- 

 much as that their judicious employment requires considerable 

 chemical acquirements. Every substance capable of increas- 

 ing the fertility of a soil, when incorporated with it, is a ma- 

 nure ; hence, the earths, when applied to regulate its retentive 

 powers, are actually manures.* Manures are animal, vegeta- 

 ble, and mineral; they directly assist the growth of plants, 

 1st, by entering into their composition; 2dly, by absorbing 

 and retaining moisture from the atmosphere ; 3dly, by absorb- 

 ing the gases of the atmosphere ; 4thly, by stimulating the 

 vascular system of the plants. Manures approximately assist 



* If the above definition and subsequent characteristics of manures are 

 correct, I cannot perceive the grounds on which Agronome considers it 

 " false philosophy " to rank common salt as one of the class. According 

 to his own experience, "it destroys weeds and worms ;" " it enters into the 

 constitution of certain plants;" " it hardens the straw;" " it makes the 

 grain plump." If these results do not constitute the substance effecting 

 them a manure, all our agricultural writers and philologists are wrong in 

 their definitions. I am glad, however, to read that Agronome confines 

 his differing with me only as to the meaning of a word ; he says, " I have 

 witnessed some extraordinary good effects from the application of salt ;" — 

 did its most strenuous advocates ever see more ? He annually " uses great 

 quantities of salt;" may the community of agriculturists profit by his ex- 

 ample ! Yet, let it be observed, in a prior communication (Vol. II. p. 306.), 

 Agronome states that salt is only good for killing weeds and worms. One 

 sentence in his last communication renders refutation needless. " I could 

 fill," he says, " several sheets on that side of the question " (viz. its enter- 

 ing into the constitution of plants, and its beneficial influence), " but am 

 engaged at present on the opposite side." In a future number, then, we 

 may anticipate that he will still more cogently confute himself. 



