218 HATCH EXPERIMENT STATION. [Jan. 



age, dried fish and blood, 18 ; cotton-seed and linseed meal, 

 19; barn-yard manure, solid and liquid,. 11 ; cotton waste 

 from factories, 6 ; potash salts of various descriptions, 18 ; 

 dry Bordeaux mixtures, 10 ; Paris green, 8 ; miscellaneous 

 analyses, 10; and compound fertilizers, 21, 



The responsibility of the genuineness of all samples sent 

 on for examination rests with the parties asking for analyses ; 

 the name of the localities they come from appears only in our 

 published records of the work to prevent misunderstandings. 

 The samples of fertilizers collected by responsible parties 

 under the direction of the officer of this department alone 

 are entered on our list of official analyses. 



Notes on Basic Phosphatic Slag {'^ 81ag MeaV) as a 



Fertilizer. 



This article appeared for the first time in our jiiarkets in 

 1886 under the name of phosphatic meal made of the Peine- 

 Thomas Scoria, a by-product of a new process introduced 

 into the manufacture of iron and steel from phosphorus con- 

 taining iron ores. 



The first sample received by me at Amherst was marked 

 " R. Weichsel & Co., Magdeburg, Germany; phosphate 

 meal made of the Peine-Thomas Scoria, guaranteed by Dr. 

 Ulex of Ham])urg, German}', to contain 21.41 per cent, of 

 phosphoric acid, corresponding to 46.74 per cent, of bone 

 phosphate; Paul Weidinger & Co., New York, acting as 

 agents." 



The first lot sent on for field experiments consisted of 500 

 pounds of ground slag meal, also a mixture of 500 pounds of 

 slag meal with 500 pounds of kainite ; to the latter had been 

 added some dry ground peat, to prevent caking. Pure slag 

 meal, it is claimed, never hardens after being ground. 



As the process of dephosphorizing the iron requires that 

 the slag should be alkaline from the beginning, an excess of 

 lime enters into the composition of the slag. To the pres- 

 ence of a certain amount of burned lime the phosphate meal 

 owes, evidently, some of its good effects as a phosphoric acid 

 source for plant food; incorporated in the soil, it alisorbs 

 moisture, and, like burned lime, it breaks up into an impal- 



