TOBACCO CULTURE. 73 



The following list contains most of the terms used in 

 stating fertilizer analyses: 



Ammonia is expressed as 



(a) Nitrogen, (&) Ammonia, (<r) Nitrogen equal (or 

 equivalent) to Ammonia, 

 Phosphoric Acid is expressed as 



(<z) Phosphoric Acid, (/;) Soluble Phosphoric Acid, 

 (c) Reverted Phosphoric Acid, (d) Available Phos- 

 phoric Acid, (e) Soluble and Available Phosphoric 

 Acid, (/") Insoluble Phosphoric Acid, (g) Total 

 Phosphoric Acid, (/i) Phosphoric Acid equal (or 

 equivalent) to Bone Phosphate of Lime. 

 Potash is expressed as 



(a) Potasjh, (b) Potash (actual), (c) Potash S. (or 

 Sul.), W Potash (Soluble), (e) Potash as Sulphate, 

 (/) Potash equal (or equivalent) to Sulphate of Pot- 

 ash, (g) Sulphate of Potash, (//) Potassium Oxide. 



Nitrogen. (Ammonia). 



(a) Nitrogen is a gas and, in this form, cannot be used 

 in fertilizers. Therefore, whenever we speak of nitrogen in 

 fertilizers we do not mean that nitrogen exists in them as 

 simple nitrogen. The nitrogen in fertilizers is always com- 

 bined with other elements, and may be present in one or 

 more different forms: (ist) in the form of Nitrates, as ni- 

 trate of soda; (2nd) in the form of ammonia compounds, as 

 sulphate of ammonia; and (jrd) in the form of organic mat- 

 ter, animal or vegetable, as dried blood, meat, tobacco stems, 

 -etc. Chemical analysis according to official methods does 



