Some Causes of Unproductiveness in Soils. 117 



their proportion in a soil is such as to produce white saline 

 efflorescences. 



Lest it should be thought that the preceding remarks apply more 

 to imaginary cases than to real ones, I may be permitted to give 

 some illustrations representing instances of barren soils which 

 have been actually brought under my notice. 



Soils abounding in organic (humic) acids are very common 

 in all peaty districts. From a large number of analyses of such 

 soils, 1 will select only one, from Meare near Bridgewater : — 



Analysis of Feat Land. 



Dried at 212°. 



*''Organic matter (abounding in humic acids) .. i)7'760 



Oxides of iron and alumina •536 



Carbonate of lime "855 



Magnesia •144: 



Potash -131 



Soda •065 



Phosphoric acid '053 



Sulphuric acid *051 



Silica -405 



100-000 

 *Contaiuing nitrogen 1*428 



In its natural state this soil contained no less than 88 per cent, of 

 water. The percentage of mineral matter, and more especially 

 that of phosphoric acid, is very trifling, and the excess of organic 

 acids is incompatible with a healthy vegetation. Lime and marl, 

 as is well known, have the power of neutralising the humic acids 

 in such peaty soils. They add, moreover, to the mineral matter 

 of the soil, and certainly are the best means of improving it. 

 I will next place before the reader 



An Anali/sis of iSoil from the Haarlem Lake, in Holland, 



Dried at 212° F. 



*Organic matter and water of combination 14'71 



Oxides of iron and alumina 9'27 



Sulphate of protoxide of iron (green vitriol) '74 



Bi-snlphide of iron (iron pyrites) "71 



Sulphuric acid united with oxide of iron as basic sulphate) -. .|,„ 



of iron J 



Sulphate of lime 1"72 



Magnesia -73 



Phosphoric acid '27 



Potash -53 



Soda ^32 



Chloride of sodium "Oi* 



Insoluble siliceous matter (clay) G9"83 



lOO^OO 



^Containing nitrogen '52 



Equal to amnioniLi '63 



