Of the above figures it may be remarked:

1. The articles are of the higher grades. The poorer articles with which the markets are infested are not taken into account. The nitrog enous superphosphates, for instance, were among the best of about fifty samples from which the selections were made.

2. The costs of the ingredients vary widely in the different articles. This is illustrated by the following figures, which represent average market-rates:

Relative values of different fertilizers.-Fish and Peruvian guanos.

309. From these figures, which represent a somewhat extensive and thorough survey of the northern and eastern fertilizer markets, it appears that, taking into account composition and price, fish manures furnish the active manurial ingredients, nitrogen and phosphoric acid, at lower rates than any other commercial fertilizers except bone manures. But in bone, the fertilizing ingredients act more slowly. Taking the form of combination, the availability, into account, the nitrogen and phosphoric acid in bone can rival those of fish, only when they are wanted for slow and long-continued use, as in "seeding down" with grass.

Next in order of cheapness come Peruvian guanos. In fairness, how ever, these ought to be compared only with the dried and finely pulverized fish guanos. Indeed, a pound of nitrogen or phosphoric acid is doubtless worth on the average considerably more, agriculturally, in Peruvian guano than in even the driest and finest fish.

*As was remarked, the nitrogenous superphosphates in the table preceding this were the best of some fifty samples of a large number of brands analyzed at this place. In that list, and in those in the appendix, can be seen the data upon which the above figures are based. The analyses from which the tables are made up were made under the direction of the writer, into whose hands not far from three hundred samples of the commercial fertilizers in the Boston, New York, Philadelphia, and Baltimore markets have lately come for examination. Fraudulent articles are excluded from the computation.

This leads us to consider the values of nitrogen and phosphoric acid in different forms of combination. In general, it may be said that nitrogen is in its most readily available forms in sulphate of ammonia and nitrate of soda; that it becomes quickly useful to the plant in Peruvian guano, more slowly so in fish, dried blood, and meat scraps, and is very long in becoming available in leather scraps, hoof and horn shavings, hair, and the like. Soluble phosphoric acid is ready for use at once. The insoluble phosphoric acid of fish guano, meat, and finely steamed bones, acts more or less quickly, but in coarse pieces of bone and in bone black its action is very slow. In the South Carolina, Nevassa, Canada, and other mineral and fossil phosphates, it is of comparatively little value.

The nitrogen and phosphoric acid in coarse fish scraps are less valuable than in fine dry fish, for two reasons: they are more bulky to transport and apply, and are less available to plants when applied.

In 100 pounds of dry guano, there will be say, 10-15 pounds of water, while 100 pounds of half-dry scrap will contain 40-50 pounds of water. To get 100 pounds of dry matter will require on the average, say, 112 pounds of guano and 180 pounds of the half-dry scrap.

Again, the finely ground fish distributed evenly and thoroughly through the soil, is readily decomposed, and thus conveyed where the largest number of roots may have access to it and its materials will be available to the roots when they find it. But the coarse scrap cannot be as well distributed either when it is applied or by natural agencies afterward, less roots will get at it, and when they do find it they will not be able to use it as well as they could the more finely ground and better decomposed guano. Less of the coarse scrap will enure to the benefit of the first crop; and of that which is left over, the phosphoric acid will remain in the soil for subsequent crops, but more or less of the nitrogen will in the process of decomposition be set free and escape into the air, or be leached away by soil-waters beyond the reach of plants, or fixed in unavailable combinations in the soil and thus lost to vegetation.

A great deal has been said about the relative values of fish and Peruvian guano. The following table gives the results of experiments bearing upon this point. The experiments were made upon twenty different beetsugar farms in and about Germany. The general plan and the details were the same for all. They were carried on by intelligent farmers, under the guidance of Dr. Grouven, director of the experiment station at Salzmünde in Prussia. The figures represent the value in German thalers of the increase in yield over unmanured plots, taking into account not only the increase of the manured crop, but the after effect during two succeeding years. The fish guano was the Norwegian,

which has more nitrogen and much more phosphoric acid than our fish guanos.

Comparing the plots which had 3 cwt. each of fish and Peruvian guano it is to be observed that

1. The Peruvian guano cost nearly twice as much as the fish guano. 2. The gain from the Peruvian guano, over and above the cost, was six times as much as that from the fish.

These results are remarkably favorable for the Peruvian guano. But it is to be noted that these experiments were on two crops of sugar-beets, with one of grain between. With other crops the results might have been very different.

Stoeckhardt, who has given as much attention to this matter as any one, infers, from a large number of field experiments made under his direction, that the fish guano is very nearly as effective as Peruvian.

Aside from its content of potash, of which fish has as good as none, the greater value of Peruvian guano, which is a fish product, must be due in the main to the fact that, as the result of the changes effected in its passage through the bird and subsequently, the ingredients have entered into new, simpler, and more available forms of combination. Taking into account composition, quality, and price, the cheapest fertilizers in the market are Peruvian guanos; next to these come fish manures.

Ways of improving fish manures.-Fermentation.

310. The advantage of these changes in the composition of fertilizers is much better appreciated in Europe than here. Several ways are recommended 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 preparing these for use. He recommends very strongly the plan of fermenting 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 process.

Composting fish fertilizers.

311. Another excellent method of utilizing fish is by composting. I can explain 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 "ammoniated" superphosphates, you will pay from 20 to 30 cents or more per pound for nitrogen, and from 8 to 20 cents per pound for your phosphoric 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 gue factory at $30 per ton."

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

nitrogen at 10 cents per pound. If rightly composted the ingredients will become available speedily and surely. For most soils and crops the increased proportion of phosphoric acid which the bone would add would be very advantageous."

"I am persuaded that my soil wants potash. Should that be put in the compost; and, if so, what is the cheapest way to get it?”

"If you can get fresh ashes cheap they will do very well. If not, the muriate of potash,' which contains 50 per cent. actual potash,' and can be bought in the larger markets at $45 or less per ton, will be best. But the ashes have the advantage over the potash-salt that they supply all the ingredients of plant food but nitrogen, and further, by virtue of their large amount of lime and alkalies, they aid the decompo sition of the matters in the compost very materially. In absence of ashes, lime will serve an excellent purpose."

Mr. D. explained his proposed method of composting, which consisted of mixing muck and mellow earth with the fish, bone, potashsalts, and lime, in alternate layers, in heaps where the urine from the stables would be caught and absorbed. From previous experience he believed that he could secure a moderately rapid fermentation which would keep the heap warm, but not too hot, and after a reasonable time have gone so far as to decompose the fragments of fish and bone and leave the whole heap in a well-rotted and uniform condition. I could only say that this seemed to me an extremely rational, sensible, and profitable way of making manure. And I cannot answer the numerous questions I receive about the best way of composting fish for manure any better than by giving the conversation with Mr. D. substantially as I recall it.

Improving fish for manure by feeding it to stock.

312. The most rational method of utilizing fish for manure, and the one which it seems to me must prove by far the most profitable way of economizing our waste fish products, is by feeding them to stock.

European farmers have learned in their practice what science has explained in theory, that just as the most reliable and useful manure is that produced in the stable and barn-yard, so this manure can be vastly improved by foods rich in nitrogen. English, French, and German farmers have found the feeding of oil cake and meal so profitable that manufacturers, entirely unable to meet the demand from the home supply, ransack the markets of Russia, India, and the United States to obtain it. Out linseed and cotton-seed products are in great demand for foreign export. After our oil manufacturers have pressed out the oil, whose value is well enough understood in the commerical world to keep it at home, the press cake, whose worth our farmers have not yet learned, is sent abroad to enrich the cattle food, manure, and purses of foreign farmers who know what it is good for and how to use it.