HISTORY OF THE AMERICAN MENHADEN. 247 



Ways of im^proring fish manures. — Fermentation. 



310. The advantage of these cbanges in the composition of fertilizers 

 is much better appreciated in Europe than here. Several ways are recom- 

 mended to bring them about. One of these is by fermentation. 



The increasing importance of fish and bone manures in German 

 agriculture has led Dr. Pagel, of the experiment station at Halle, to 

 undertake a series of experiments to gain light upon the best means of pre- 

 paring these for use. He recommends very strongly the plan of ferment- 

 ing them with urine : " The method of fermentation furnishes a most 

 excellent means for transforming the nitrogen in manures of organic 

 origin, which is insoluble and slow in its action, into more soluble and 

 consequently more active forms. It is hence peculiarly applicable to 

 ground-bone and fish guano." He recommends to add about 30 quarts 

 of urine to 100 pounds of bone or guano, and cover the heap with plaster 

 (gypsum) or earth to prevent the escape of ammonia. If this is properly 

 done, the mass will ferment, and the temperature rise to a little above 

 100° Fahr. The completion of the process, for which three or four weeks 

 should suffice, is indicated by the cooling of the heap. Pagel found 

 nearly one-half the nitrogen of fish to be made soluble in water by this 



l)rocess. 



Composting fish fertilizers. 



311. Another excellent method of utilizing fish is by composting. 

 I can exi^lain this in no better way than by referring to the experience 

 of one of the most intelligent and successful farmers in our State, Mr. 

 D., who lately called upon me to inquire about this subject. Mr. D.'s 

 problem was simply how to get fertilizing materials for his soil in the 

 best and cheapest manner. He proposed this question : 



'' I understand that the superphosphate manufacturers make their 

 fertilizers of fish scrap and phosphates, treating them with oil of vitriol 

 to make the phosphoric acid and nitrogen more available. Now can't I 

 accomplish the same by composting in my barn-cellar ? I understand 

 the elements must go out of their original combinations into others 

 before they can become useful to my plants, and that the acid and the 

 manufacturing help this change along. I can get fish scrap for $17 per 

 ton. Can I not bring this change about in a compost-heap, and will it 

 not be a great saving to me ?" 



The answer was plain : " Fish scrap at $17 per ton will bring nitrogen 

 at say 10 cents and phosphoric acid at 5 cents per pound. In " am- 

 moniated " superphosi)hates, you will pay from 20 to 30 cents or more 

 per pound for nitrogen, and from 8 to 20 cents per pound for your phos- 

 phoric acid." 



" Do I need a phosphate with the scrap ; if so, will bone be as good 

 as anything ? I can get ground bone from a g ue factory at $30 per 

 ton." 



" The bone at that price will give pliosphoric acid at say 5 cents and 



