-jQ A TREATISE ON THE CONNECTION OF 



"SULPHAT OF IRON, OR GREEN VITRIOL. 



4 



■ This salt is formed naturally, in many places in great 

 abundance, by the process of oxygenation, from sulphu- 

 reous or pyriteous substances. These matters are gene- 

 rally found accompanying the coal strata, as well as in 

 coal itself; particularly in such coals as are sulrhureous. 

 This salt is very soluble in water, and is in a high de- 

 gree injurious to vegetation, when it abounds in soils 

 consisting of poor clay and siliceous matter, without any 



admixture of vegetable or calcareous substances. 



It is decomi->osed by alkaline salts, forming ther&with 

 vitriolated tartar, Glauber salt, vitriolic ammoniac, gypsum, 

 and Epsom salt. When added to soils containing calcareous 

 matter, and a due proportion of animal and vegetable sub- 

 stances, it has been found, when not used in too great 

 quantities, to have produced beneficial effefls in promoting 

 the growth of grass ; but experiments have not as yet 

 been made fully to ascertain its elFefts on arable land. 



NITRAT 



