COMMERCIAL FERTILIZERS. 



REPOKT OF STATE CHEMIST. 



Purdue University, Lafayette, Ind., Feb. 7, 1885, 



Alex. Heron, Secretary State Board Agriculture : 



Dear Sir — Forty-six samples of fertilizers sent by manufacturers were analyzed 

 in 1884, as required by law. The percentages "of soluble and reverted phosphoric 

 acid" have been separately reported (as by my predecessor), although this involves 

 one more determination for each analysis than the law prescribes. The greater 

 part of the analytical work was carefully performed by W. H. Peters, A. G., Assist- 

 ant Chemist. 



In computing the valuation of fertilizers, a lower estimate is given for some 

 ingredients than in former years. In accordance with mean values estimated by 

 State chemists of several of the Middle and Eastern States for the year 1884, 1 have 

 allowed 



10 cents per pound for soluble phosphoric acid. 

 9 cents per pound for reverted phosphoric acid. 



5 cents per pouud for insoluble phosphoric acid. 

 15 cents per pound for ammonia. 



6 cents per pound for potash. 



The retail selling prices of the fertilizers analyzed are not reported to this office ; 

 the values above are taken from the most reliable data at hand, but they may not 

 accord with market rates in this State. 



Great caution should be used by those who contemplate purchasing, in regard to 

 the column of "Estimated Values per Ton," as printed in the following table. It will 

 be observed that every pound of soluble phosphoric acid is rated at twice the value 

 of insoluble phosphoric acid. The benefits of the latter, in the form of ordinary 

 ground bone, are well known. Superphosphate (bone or phosphatic rock, made 

 soluble by sulphuric acid) is more expensive, will yield quicker returns, and is 

 properly considered more valuable ; but, on the other hand, it is more liable to in- 

 jure the crops when applied in excess, while it is also more likely to wash out of 

 the soil and be lost, in case of excessive rains. The " Estimated Values " are be- 



