18 BOARD OF AGRICULTURE. 



because of those efforts, coming from such men, to elevate us as 

 an agricultural community, and to make us what we should be 

 and ought to be, — it is upon that ground especially that I wel- 

 come here to-day the distinguished men who compose the Board 

 of Agriculture of Massachusetts. 



SALT AND ITS USES IN AGRICULTURE, 



BY PKOF. CHARL-ES A. GOESSMANN, PH. D. 



The discovery of common salt — in the commercial meaning 

 of that article — belongs within the earliest stages of the human 

 family. Wherever we find it mentioned upon the first pages of 

 history it is spoken of as something known. Its presence in the 

 waters of the ocean, of various lakes, and of certain springs, it 

 appears, was not less recognized, than its occurrence as an exu- 

 dation of the soil in particular localities. 



Saline exudations so frequently found in the Orient, in com- 

 mon with the residues of accidental evaporations of some of 

 those natural saline solutions, previously alluded to, have fur- 

 nished, in all probability, its first supply. Its manufacture for 

 commercial purposes by artificial heat applied to iron pans,' 

 similar to our present mode of working, has been credited to 

 ancient Romans. Grecian and Roman writers, even centuries 

 before the Christian era, begin to treat of it from a scientific 

 point of view, although sometimes under a different name. 

 Dioscorides, at the end of the first century, speaks of its peculiar 

 cleavage, and describes already some of the differences between 

 the salt resulting from the evaporation of sea-water and the 

 rock salt. The famous alchemist Geber, who lived within the 

 eighth century, it is stated, was engaged in experiments to refine 

 the commercial common salt for chemical ^Durposes. 



The idea regarding the chemical constitution of the pure salt 

 has changed quite naturally during the progress of the natural 

 sciences, and of chemistry in particular. Our present view con- 

 cerning its composition could scarcely have been advanced 

 before 1810. The isolation of the metallic elements of the 

 alkalies, and the proper recognition of the nature of the muriatic 

 acid had to precede, before Sir Humphrey Davy could conceive 

 the idea of proving by experiment, that the pure salt consisted 

 of the two elements, sodium and chlorine. "We observe at the 

 close of the last and the beginning of the present century, 



