102 PRINCIPLES OF GARDENING. [CH. II. 



An Essay on the Uses of Salt in Agriculture, by my 

 brother, Mr. Cutlibert Johnson. 



Parts. 

 ^Horse dung evaporated previously to 

 dryness, at a temperature of 100°, 

 absorbed during an exposure of three 

 hours to air saturated with moisture 



at 62^ 145 



Putrefied tanners' bark, under similar 



circumstances, (66 ') 145 



Unputrefied tanners' bark . . . . 115 



Cow dung 130 



Pig ditto 120 



Sheep ditto 81 



Pigeon ditto 50 



Refuse marine salt (60^) 49 J 



Soot (68°) 36 



Burnt clay 29 



The richest soil (in one hour) . . . 23* 



Coal ashes 14 



Lime (part carbonate) 11 



Crushed rock salt 10 



G}^sum , 9 



I Chalk 4 



O 

 O 



o 



The absorbing power of a manure is much influ- 

 » Sir H. Davy. 



