On the Employment of Salt as a Manure. 5 



soil that had had no salt applied. We must not either 

 imagine, that plants absorb the salt of necessity, it beiri<» pre- 

 sented to them in solution, for Saussure has demonstrated by 

 experiment that plants have the power of selecting salts from 

 their solutions ; acetate of lime and common salt being dissolved 

 in the same water, some plants of Polygonum Persicaria, &c, 

 absorbed a considerable portion of the latter salt, but rejected 

 the former entirely. (Saussure's Recherches, p. 247 — 61.) I 

 never tested with nitrate of silver the infusion of any plant that 

 did not indicate the presence of an alkaline muriate. Such 

 being the fact, I am not aware of any reason that should forbid 

 us considering common salt as an essential constituent of some 

 plants ; if we allow that it is such of the blood and other parts 

 of animals, and if it is an essential constituent, they must de- 

 rive it from their food. Sir H. Davy, in his Agricultural 

 Chemistry, (2d ed. p. 337,) says, " when common salt acts as a 

 manure, it is probably by entering into the composition of the 

 plant in the same manner as gypsum, phosphate of lime, &c." 

 We could hardly attribute the benefits arising from these to 

 plants to their stimulating qualities. 



I offer these observations, Sir, not in the belief that they are 

 new to you, but in the hope that they may induce you to a 

 more full examination of the evidence for and against the em- 

 ployment of salt as a manure, an examination which I am sure 

 could not fail of securing you to it as a friend, which I am the 

 more anxious you should, being an advocate for it myself, as 

 you stand in your editorial capacity as one of the beacons of 

 horticulture. I am, Sir, yours, &c, 



G. W, Johnson. 



We shall not argue with Mr. Johnson or Mr. Collyns, 

 (Gafd. Mag. p, 401.) as to whether salt be a stimulus or a 

 manure, but rather strongly recommend the able communic- 

 ation of the former to the practical reader, and await the light 

 which may be thrown on the subject in a future number by 

 the latter correspondent. Used in small quantities, we are 

 very much inclined to think with Mr. Cline, that salt may be 

 found " of as much benefit to land as to the human constitu- 

 tion." It does not follow, that because it is used in large 

 quantities to destroy, it may not be used in small quantities to 

 promote, vegetation. We lately saw an approach road in 

 Staffordshire, thickly coated over with salt, the article being 

 in that part of the country abundant and cheap; we hope, 

 therefore, that some of our readers in that quarter will try 

 some experiments, and communicate the result. Suppose we 



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