CHEMICAL DEPARTMENT. 173 



Carelessness in handling is the cause of nearly if not all the accidents which 

 result from such poisons. I wish to thank C. P. Grillett, whose painstaking, 

 conscientious and intelligent assistance has been of great value to me in these 

 experiments. 



A. J. COOK. 

 Agricultural College, Mich., April 30, 1887. 



No. 27.— CHEMICAL DEPARTMENT. 

 COMMERCIAL FERTILIZERS— INSPECTION FOR 1887. 



Act No. 28 of the Session Laws of 1885 requires the analysis each year of 

 every commercial fertilizers offered for sale in this State if its retail price 

 exceeds $10 a ton. The manufacturers of fourteen different brands of such 

 fertilizers have applied to the Secretary of the Board of Agriculture for a 

 license to sell said fertilizers and deposited the fee required by law. I have 

 gathered in the open market specimens of these fertilizers, analyzed them, 

 and present in tabular form the results of such analysis in comparison with 

 the composition as claimed by the manufacturer. By comparing the compo- 

 sition as it is "claimed" and ''found," one can readily see whether the 

 fertilizer comes up to the standard. 



This law is designed to guard the public against fraud by preventing the 

 sale of inert or spurious materials in the place of substances really valuable.. 

 When we consider that leached ashes and soap-boilers' waste have been 

 offered for sale as "superphosphate," and a premium claimed for such 

 "superphosphate" from the State Agricultural Society, and that parties in 

 a neighboring State endeavored to sell marl as "Buckeye Phosphate," we see 

 that State supervision is necessary to protect the public. 



The law does not prescribe what the fertilizer shall contain, but holds the 

 manufacturer rigidly to the standard he sets up for his own fertilizers in 

 respect to the three most important ingredients, viz. : available nitrogen, 

 phosphates, and potash. 



The inspection required by this law gives no information about the use of 

 the fertilizers, the kinds of soil best adapted to their profitable use, the kinds 

 of crops most benefited, the time to apply them or the quantity to use. This 

 desirable information does not come within the scope of this investigation. 

 Some day I hope to issue a Bulletin to discuss some of the above topics, but 

 the public must remember that the chief object of this law is to prevent 

 fraud. 



If any one wants to estimate the money value by the commercial value of 

 the three principal ingredients, he can readily do so by taking the value of 

 nitrogen as 18 cents a pound, of soluble phosphoric acid 8 cents, of reverted 

 phosphoric acid 7^ cents, of insoluble phosphoric acid 5 cents, and potash 

 as 5 cents a pound. For example, take a fertilizer containing 3 per cent of 

 active nitrogen, 7 per cent soluble, 2 per cent reverted and 1 per cent insol- 

 uble phosphoric acid, and 2 per cent of potash. This would give the follow- 

 ing results for every 2,000 pounds: 



