KINDS OF INSECT PESTS 625 



would be acceptable in almost every State under the present 

 laws. If this double statement were prepared in the simplest 

 form it would not be objectionable, and it would not require any 

 immediate or special legislation, excepting in one or two States. 

 The following form is suggested: 



Per cent. Per cent. 



Nitrogen 1.4 = Ammonia 1.7 



Available phosphorus 6.4 = Available phosphoric acid 14.4 



Insoluble phosphorus 0.6 = Insoluble phosphoric acid 1.4 



Total phosphorus 7.0 Total phosphoric acid 15.8 



Potassium 3.9 = Potash 4.7 



526. Ingredients Expressed as Ions. The expressions of the 

 results of fertilizer analyses in the ionic nomenclature is prac- 

 ticed by the Bureau of Soils. One of the advantages of this 

 system is to secure an expression of analytical data in a man- 

 ner conformable to the piesent leading theory of the constitu- 

 tion of matter. This method of expression is open to the same 

 criticism as that applied to the elemental system. It has the 

 merit however, not possessed by the elemental system, of being 

 more in accord with modern theories. 



527. General Conclusion. It appears therefore as the general 

 consensus of opinion in the United States that the present sys- 

 tem for the expression of the results of fertilizer analyses and 

 also of the same elements as determined in the soil should be as 

 follows : Nitrogen N ; phosphoric acid P 2 O 5 ; potash K,O ; 

 silica SiO 2 ; soda Na 2 O; lime CaO; magnesia MgO; ferric oxid 

 Fe 2 O 3 ; alumina A1 2 O 3 ; sulfur trioxid SO 3 ; carbon dioxid CO 2 . 

 This would not preclude the additional statement of the data in 

 cither elemental or ionic form as described. 



METHODS OF ANALYSIS OF INSECTICIDES AND 

 FUNGICIDES 



528. Kinds of Insect Pests. Various groups of insects act 

 harmfully on plants, or animals, or as pests in households, or 

 granaries ; and require special methods of treatment to kill them. 94 

 Among these classes of insects may be mentioned internal feed- 

 ers, subterranean insects, insects affecting stored products, house- 



94 Haywood, Manuscript Communication to the Author, 1908. 



