66 Parkes on the Use 



has the effect of promoting the health and growth of vege- 

 tables. 



2dly. That it has the property of rendering fruit trees and 

 esculent plants unfit for the food or the habitation of worms 

 and insects. 



3dly. That common salt is one of the mos£ efficacious sub- 

 stances that can be employed in a garden for the destruction 

 of worms and insects ; and 



4thly. That common salt may, with material advantage, be 

 likewise used for the destruction of weeds, or other noxious 

 vegetables. 



Under the first division of our subject, it is to be observed, 

 that the celebrated Dr. Darwin, when treating of common salt 

 as a manure for land, asserts, that this substance *' is a stimulus 

 which excites the vegetable absorbent vessels into greater 

 action than usual, and that in a certain quantity, it increases 

 their growth, by enabling them to take up more nourishment in 

 a given time ; and consequently, to perform their circulations and 

 secretions with greater energy." Sir Humphry Davy, from what 

 he says in his Agricultural Chemistry, seems, on the other hand, 

 to think it also probable, '' thai common salt acts as a manure, 

 by entering into the composition of the plants, somewhat in the 

 same manner as gypsum, phosphate of lime, and the alkalies." 



These opinions will be thought to have great weight ; but as 

 few persons, comparatively speaking, will be able to confirm 

 them by their own experience, in consequence of the very limited 

 attention that has hitherto been bestowed on the use of salt in 

 horticulture, the more useful way, perhaps, of treating, this sub- 

 ject, will be to lay before the Society the evidence of those prac- 

 tical men, who have already published the results of their ex- 

 periments, and then to draw such conclusions as their commu- 

 nications may seem to justify. 



Dr.Brownrigg, who, in the year 1748, published a valuable 

 work " On the Art of making Common Salf'^ makes the follow- 

 ing statement : 



** Salt," says he, " contributes greatly to fructify the earth, 

 and when properly used as a manure, affords ample nourish- 



