134 Commercial Gardening 



the majority will need to be specially designed, or accuracy in results 

 cannot be looked for: 



1 balance. 2 filtering funnels, 6 in. 



Palette knife. 1 stoppered cylinder, 750 cub. cm. 



Beakers. 6 at 300 cub. cm. capacity. 1 desiccator 



2 at 600 1 wash bottle for water. 



1 Winchester quart for citric digestion. 1 alcohol. 

 C0 2 apparatus. 1 ,, ammonia. 



2 Berlin porcelain dishes, 4 in. 1 ,, hydrochloric acid. 

 4 crucibles. 1 nitric acid. 



1 distilling flask and condenser. 1 pestle and mortar. 



1 closed vessel to supply steam, to 6 glass rods. 



act as small boiler. 1 large sieve, 4 meshes to inch. 



2 conical flasks with Bunsen valve. 1 small ,,16 

 2 burettes, 50 cub. cm. Filter stand. 



1 pipette, 25 cub. cm. Water bath. 

 1 graduated measure, 500 cub. cm. oven. 



1 100 Burette stand. 

 6 clockglasses. Filter papers. 



2 filtering funnels, 4 in. 1 pair crucible tongs. 



Lime Carbonate. The first constituent to be estimated will be the 

 lime carbonate in the soil. Proceed as follows: Place a small quantity 

 of soil in a test tube or other convenient vessel, such as a cup; fill up to 

 1 in. from bottom; pour over sufficient strong hydrochloric acid (commer- 

 cially known as spirits of salt) to cover the soil. If the soil contains a 

 reasonable amount of lime carbonate a vigorous effervescence will occur, 

 but if there is little or no disturbance then lime or lime carbonate must 

 be added to the soil at once. The chemical action is roughly as follows: 

 Hydrochloric acid (HC1) attacks the calcium carbonate (CaCO 3 ), driving 

 out carbonic acid gas and forming calcium chloride. 



The more accurate method adopted by chemists is as follows: 



To estimate the available constituents of the soil, 200 gm. are mixed 

 with 2000 cub. cm. of 1-per-cent citric acid solution and left for a week, 

 the whole being shaken up once a day. The solution is then filtered 

 and divided into separate portions of 500 cub. cm. 



Phosphates. To estimate the soluble phosphates 500 cub. cm. are 

 evaporated until the volume is reduced to about 100 cub. cm. and then 

 allowed to cool, and 40 cub. cm. of ammonium molybdate solution added, 

 well stirred, and allowed to stand in a warm place. This is then filtered 

 and the precipitate washed, first with dilute nitric acid and then with 

 very small quantities of distilled water. The precipitate is then dissolved 

 in ammonium hydrate and 20 to 30 cub. cm. of magnesia solution added, 

 the whole being allowed to stand for twelve hours for complete pre- 

 cipitation. The resulting precipitate is now filtered off and washed with 

 dilute ammonia dried and incinerated in a crucible, the residue being 



