238 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



laS.— REPORT OF ANALYSIS OF A SAMB»L,E OF FISH OVANO MADE 

 FROM SAI>ITIO!V OFFAI^, BY MH. JOSEPH SPRATT, OF VICTORIA, 

 BRITISH COI^UmiSIA. 



By Prof. W. O. ATWATER. 



The sample, as received, was fine, dry, and in excellent mechanical 

 condition. The analysis shows an usually large amount of nitrogen 

 and i)hosphoric acid. 



ANALYSIS. 



Per cent. 



Water 11.28 



Nitrogen 9. 88 



Equivalent to ammouia 12. 00 



Phosphoric acid 5. 51 



Fat (oil) 11.61 



Statements explanatory of the composition, commercial values, and 

 agricultural uses of fish guano may be found in the report of the United 

 States Fish Commission, 1877 (pp. 229,230, &c.), from which it will be 

 seen that this sample is of unusually high grade. It has indeed higher 

 percentages of both nitrogen and phosphoric acid, and is, consequently, 

 more valuable for fertilizing purposes than any of the specimens men- 

 tioned in that report. It has also a large content of fat, which would, 

 with the nitrogenous matter, give it a very high value for food for stock, 

 in case, as is by uo means impossible, fish refuse should ever come into 

 use for this purpose. 



I learn by inquiry that fish guano, like other nitrogenous fertilizers, 

 is just now rather cheap and not much in demand in the market. "The 

 10 per cent ammonia grade has," I am told, "been selling in bulk at 

 factory (near New York) at $24 per ton." This is at the rate of $2.40 

 per unit of ammonia. At this rate guauo, like Mr. Spratt's sample, 

 with 12 per cent ammonia, would be worth $28.80 per ton. The per- 

 centage of phosphoric acid is very large, and some buyers might; make 

 allowance for it. These, however, are matters upon which I am hardly 

 competent to give fall information. 



As a fertilizer, fish guano is used mainly in connection with phos- 

 phates and potash salts. Used alone its effect is generally inferior to 

 that of materials which contain relatively more phosphoric acid and less 

 nitrogen, and it has, on that account, not come into general use among 

 farmers. It is, however, very much employed by manufacturers as an 

 ingredient of mixed fertilizers. Of late nitrate of soda has been very 

 cheap and has reduced (though I presume only temporarily) the de- 

 mand for fish fertilizers. In short, the sample is one of a very high 

 grade of fish guano, and unless I greatly err such material will be in- 

 creasingly in demand in the future. 



Chemical Laboratory, Wesleyan University, 



Middletown, Conn., July 9, 1884. 



