12 



CONTROL SERIES NO. 158 



MAGNESIUM OXIDE GUARANTEES 



There has been some confusion regarding magnesium oxide guarantees. So 

 far as the Fertilizer Control Service is concerned, the magnesium oxide guaranteed 

 must be in a water-soluble form only if the guarantee is stated in terms of water- 

 soluble magnesium oxide. Otherwise the magnesium oxide may be present either 

 in a water-soluble or a water-insoluble form, so long as the total amount of mag- 

 nesium oxide found equals or exceeds the amount guaranteed. 



Because of several inquiries regarding the form in which magnesium oxide 

 is present in the different fertilizers, all fertilizers carrying magnesium oxide guar- 

 antees were analyzed for both total and water-soluble magnesium oxide. The 

 followina table lists the results. 



Mixtures Carrying Magnesium Oxide Guarantees 



Manufacturer 



Brand Name and Grade 



American Agricultural Chemical Co. 



Agrico for Potatoes 5-10-10, 2% magnesium oxide. 



Apothecaries Hall Co. 



Liberty High Grade Market Gardeners S-8-7, 2% magnesium 

 oxide 



Liberty Fertilizer 5-10-10, 2% magnesium oxide 



Liberty 6-8-8, 2% magnesium oxide 



Armour Fertilizer Works 



Big Crop 5-10-10, 2% magnesium oxide 



Joseph Breck & Sons Corp. 



Brexone Garden-Gro 5-10-10, 2% magnesium oxide 



Consolidated Rendering Co. 



Corenco 5-10-10, 2% soluble magnesium oxide 



Davison Chemical Corp. 



Davco Granulated 5-10-10 Potato Food, 2% magnesium oxid 



Eastern States Farmers' Exchange, Inc. 



Eastern States 5-10-10, 1% magnesium oxide 



Eastern States 5-15-15, 1% magnesium oxide 



Eastern States 8-4-8 Tobacco, 2% magnesium oxide 



Eastern States 8-12-12, 2% magnesium oxide 



Eastern States 8-12-12 L. C, 2% magnesium oxide 



Eastern States 8-12-16, 2% magnesium oxide 



Eastern States 8-16-16, 1% magnesium oxide. . 



Eastern States 10-10-10, 1% magnesium oxide 



Found Percent 



Total 



Magnesium 



Oxide 



2.26 

 2.46 

 2.58 

 2.46 

 [2 04 



3.12 

 2.90 



/4.64 

 \4.05 



(3.19 



12.75 



f2.90 

 13.45 

 12.62 

 [3.62 



1.12 



/4.71 

 \4.64 



3.28 



3.97 



2.46 



/1.81 

 \l-50 



fl.25 

 \1.75 



Water-Soluble 



Magnesium 



Oxide 



1.36 

 1.27 

 1.45 

 1.72 

 1.18 



1.13 

 2.22 



2.49 

 2.26 



1.22 

 .91 



1.00 

 1.13 

 1.27 

 1.54 



.68 



1.63 

 1.59 



2.63 



2.72 



2.22 



1.49 

 1.49 



.68 

 .82 



