292 STATE BOARD OF AGRICULTURE 



iiM' on tlio farm. Tt iiiay scr\c, liowfNcr. as a hasis of coniiiarisoii hctweon dillVrent 

 Itiaiuls ot fcrtili/t'is. 'J'lu' iclialilc test of Xhv \'aluo is (IctcniiiniMl liy its use on a 

 ;:i\t'n soil ami <to|i — worth iiioif tliaii all tlK'orct ical disciissions and deductions. 

 Vi't there are certain general considerations wiiich yo to show tiie prohahlc henefit of 

 any fertili/inji element when used on a certain kind of soil and croj), which will he 

 of some henefit in select iiii: a fcrtili/er. 



'n:i;.Ms i:xit,ai.\i:i>. 



In the table giving the results of analysis of commercial fertilizers there are cer- 

 tain terms used which require explanation: "Available nitrogen, estimated as 

 ammonia;" under "Phosphoric acid" the terms "Available P.., 0^;" "Insoluble 

 P., O5;" "Total P, O," and "Potash s duble in water, estimated as K,, O." 



Niti'Ogen may exist in available form either as a salt of ammonia, a nitrate, or in 

 organic material such as dried blood, and be equally valuable in these several 

 forms. But for ease of comparison in different manures chemists estimate it as if 

 all these forms of niti-ogen existed in the form of ammonia. Chemists estimate the 

 compounds of phosphorus in manures as anhydrous phosphoric acid, P... O,; that is, 

 phosphoric acid deprived of water; when this anhydride combines with water, the 

 acid is formed. Thus if three molecules of water are added to one of P.. Os two 

 molecules of phosphoric acid are formed .SH.jO + P., O5 = 2 H3 PO4 = phosphoric 

 acid. The Pj O5 in separate form dyes not exist in any soil, but this expression is 

 chosen because the amount of this combination of phosphorus is easily indicated, 

 without considering what material the acid may be combined with. "Available 

 P.j Os" signifies the per cent of the acid in a form directly usable by the plant: 

 "Insoluble Po O5," the per cent of acid in the condition of phosphate rock. By 

 adding together the "Available" and "Insoluble" we get the "Total P, O.,." 



The "Potash soluble in water, estimated asK^O," is the soluble potash salt esti- 

 mated only as regards the oxide of potassium = KiO^oxide of kalium or potassium. 



SKLKCTIXG SI'KCTMKXS OF FKiri'irJZKUS FOR AXAT.VSIS FOIt THF liFLLFTIX. 



The law requires (he manufacturer or dealer to deposit a specimen of each fertilizer 

 with the secretary of the hoard, hut sucli specimens are never used for analysis 

 unless it is im])ossihle to ol)tain specimens from the material exposed for sale in the 

 open market. The ohject is to deal with the same material that the farmer buys 

 for himself. In this way any collusion hy which a richer fertilizer is analyzed than 

 will he fo\ind in tlie fertilizer oH'ercd for sale in the open market, is ])revented. 



As the fertilizers arri\'e at somewhat uncertain ])eriods and are distril)utcd over 

 a wide extent of territory, the fiatliering of the 5pe<imcns recpiires nuich travel and 

 time in order to cover the wlude area of fertilizer consumption. 



The following stations and names of the dealers give some idea of the thoroughness 

 with which this M'oik is done. It is not feasible to visit every dealer, hut the aim 

 is to j:o over the more impf)rtaiit districts for tlie specimens. 



Some of the parties visited on the fertilizer collection from May (> to June 20. 



West Bav C'itv. — Ueo. L. ilosher. E. S. Fitch. Geo. L. Frank. 



Bav Citv.— Rechlin & Frank. Jenison Hardware Co.. R. C. Bialey. Boutell Bros. & 

 Co., Presley & Layer. F. ^^■. Bradlield. V. V. fJoddene. 



Saginaw. — Saginaw Hardware Co.. .lohn 1*. Dcrhv, II. M. Xcumaiiii, C. \V. Bruske, 

 Popp & WoUe. W'a]'/. Hardware Co. 



Care— C. E. :Mudge. Caro Elevator Co.. Caio Sugar Co.. T. W. Van Tine. 



Fair Grove.— H. W. Houghtaling. IMitchill & Co.. Richardson Elevator Co. 



Bad A\e. — J. G. WrJLilit, Meriditli iJc Pvvckman. Comfort Produce Co.. \Vm. Rapson 

 & Sons. Lankin & ]:)uudas. A. T. :\IcD<)nald. W. H. Carev. 



Ubly!— H. J. Wilkson, G. W. Sparling. John Cope, J). H. Pierce & Sons, Thomas 

 Richardson. 



(\irsonville.- — Hartzhorn <!i; Anderson. 



Sanilac Center.— E. A. McP]icr>(.n. Wm. Pol.crts. Walker & Cou-hcll. Dell T. 

 Dawson. 



Port Sanilac. — R. Godfrev. Wm. Greening. 



Imlay City.— F. Booth. 'Walter Walker. Slceman & Burkholdcr, Andrew Wood, 

 John W. Green. ^Marshall Bros. 



North Branch. — Daniel Orr. ^Vm. Butler. ]\Iartin Fay, W. W. Harrington, North 

 Branch Grain Co. 



