50 



soils have generally 110 effect on litmus paper, or show only a slight al- 

 kaline reaction. 



Make a water solution of the soil, and test the solution for lime with 

 ammonium oxalate; for sulphuric acid with barium chloride, after acid- 

 ulating with hydrochloric acid; for iron, with ammonia; and for chlorides 

 with silver nitrate. An excess of any of the three latter would indicate 

 that the soil contains injurious quantities of them. 



Boil some of the soil with nitric acid, and after filtering off the in- 

 soluble residue, test the solution with ammonium molybdate for the 

 presence of phosphoric acid. 



In a hydrochloric acid solution of the soil the different bases may be 

 tested for as in the quantitative analysis. If an effervescence is produced 

 on adding the acid to the soil, the presence of carbonate of lime is indi- 

 cated, but should none occur, but analysis show that lime is present, it 

 is probably in the state of sulphate or gypsum. 



