hydrates and fats to considerable extent, but their peculiar work must all be done by themselves. Such is the concurrent testimony of a vast amount of experimenting.

Again, of the whole ration consumed only a portion is digested and used to supply the animal's wants; the rest is voided as excrement, and valuable only for manure. It is important, then, that as much should be digested as possible. The value of the food will depend upon the amount the animal digests from it.

Economy in feeding requires, then, that the greatest amount of food be digested, and that this digested material contain sufficient albuminoids.

An excessive proportion of albuminoids is, however, uneconomical. The albuminoids are the costliest parts of the foods. No more should be used than necessary.

Proper proportions of digestible albuminoids, carbohydrates, and fats in the food are the chief requisites of economical feeding.

Digestion of foods by animals, as tested by European experiments.

316. The digestibility of different foods and food mixtures by dif erent animals under varying circumstances has been tested by a very large number of experiments in the German experiment stations. The method consists in feeding animals with rations of known amount and composition, carefully collecting, weighing, and analyzing the excre ments, the undigested portion, and subtracting the latter from the former. The following examples will serve for illustration:

In the stables of the station at Weende, under the direction of Professor Henneberg, two full-grown oxen were fed during one period of about two weeks with oat straw, during another period with bean straw, a third with clover hay, a fourth with meadow hay, and so on. During some of these periods a small amount of bean meal was added. The ration was at all times such as to keep the animals in fair and uniform condition. Careful weighings and analyses were made of fodder and excrement, that is to say, of the total and the undigested material, and from these the digestibility of the food was calculated. For instance, in one of the experiments of this series the ox consumed daily 16.9 pounds of meadow hay, or what is called here "English grasses."

In another experiment the daily ration consisted of 17.87 pounds of oat straw, and 1.82 pounds bean meal.

The first digestion experiments were made some twenty years ago by Henneberg and Stohman, in the experiment station at Weende in Hanover. Their example has been followed in other places. Four years ago the number of digestion experiments amounted to over one thousand, and they have been increasing rapidly in numbers every year since then. These experiments, each one of which has been conducted with an amount of labor and exactness never equaled by a single experiment in this country, have led to many very interesting and weighty results.

What is essential to economy in feeding.-Albuminoids and carbohydrates. 317. The following are among the most important for our present purpose:

1st. Poor foods, like marsh-hay, late-cut bay, straw, cornstalks, and chaff, contain good percentages of digestible material. Their low feeding value is due, not to their lack of nutritive substance, but to its poverty in nitrogen. By adding to them concentrated foods rich in nitrogen, like oil-cake, cotton-seed, bean and pea meal, or nitrogenous animal matters, such as meat scrap and fish, rations are made equal in every respect to the best grass, young-cut hay, or grain.

2d. The digestion of foods, particularly of mixed rations, depends upon the proportions of its constituents. With too little nitrogen the digestion is incomplete. Adding concentrated foods rich in nitrogen to coarse foods promotes digestion. Excess of carbohydrates decreases it. Oil-cake, meat scrap, or fish added to poor hay or straw secures the most complete digestion of the whole ration. But if potatoes or other starchy food are used in considerable quantity the less of the coarse food will be digested.

There is still another principle of great importance to be noted. Well-manured plants are much richer in albuminoids than poorly manured. Bountiful fertilizing not only increases the quantity of the crop but improves its quality also.

The farmer who keeps his land in good condition gets larger yields; the produce contains more digestible substance for his stock, and the nutritive material is richer in the most valuable ingredients of all, the albuminoids.

Composition and valuations of various food materials.-German tables.

318. Fuller details and tables illustrating the principles here presented, may be found in a series of articles on science applied to farming, in the "American Agriculturist" for 1874-76, and in a lecture on "The Results of Late European Experiments on the Feeding of Cattle,” in the report of the Connecticut Board of Agriculture for 1874. A briefer statement of the subject is given by Prof. S. W. Johnson in the report of the Connecticut Agricultural Experiment Station for 1877. This latter contains a table which is interesting as including, with German analyses and valuations, some analyses of American products; with the rest, two samples of fish-scrap. The table is explained by Professor Johnson as follows:

"The following table of the composition, content of digestible nutritive ingredients, and money value of a few of the most important feeding-stuffs, is taken from the German of Dr. Emil Wolff, of the Agricultural Academy at Hohenheim, and represents the most recent and most trustworthy knowledge on these subjects.*

"The composition of feeding-stuffs, as here stated, is the average result of the numerous analyses that have been made within twenty-five years, mostly in the German experiment stations.

"The quantities of digestible ingredients are partly derived from actual feeding experiments and are partly the result of calculation and comparison.

"The percentages of the three classes of digestible matters, viz, al buminoids, carbohydrates, and fat, form the basis for calculating the money value of feeding-stuffs. The values attached to them by Dr. Wolff are the following, the German mark being considered as equal to 24 cents, and the kilogram equal to 2.2 pounds avoirdupois:

"1 pound of digestible albuminoids is worth 43 cents.

"1 pound of digestible fat is worth 43 cents.

"1 pound of digestible carbohydrates is worth of a cent. "These figures express the present relative money values of the respective food-elements in the German markets. Whether or not these values are absolutely those of our markets, they represent presumably the relative values of these elements approximately, and we may provisionally employ them for the purpose of comparing together our feeding-stuffs in respect to money value. These money or market values are to a degree independent of the feeding values. That is, if of two kinds of food, for example Hungarian hay and malt sprouts, the one sums up a value of $0.66 and the other a value of $1.31 per hundred, it does not follow that the latter is worth for all purposes of feeding twice as much as the former, but it is meant that when both are properly used, one is worth twice as much money as the other. In fertilizers we estimate the nitrogen of ammonia salts at 24 cents per pound, and solu

* From "Mentzel u. Lengerke's Kalender," for 1878.

ble phosphoric acid at 123 cents; but this means simply that these are equitable market prices for these articles, not that nitrogen is worth twice as much as soluble phosphoric acid for making crops. In the future more exact valuations may be obtained from an extensive review of the resources of our markets, in connection with the results of analy ses of the feed and fodder consumed on our farms.

"The column headed Nutritive ratio' in the table gives the propor tion of digestible albuminoids to digestible carbohydrates, inclusive of fat.* To allow of directly comparing the money value of feeding-stuffs with some universally accepted standard, the last column gives a comparison with good average meadow hay taken as 1."

Average composition, digestibility, and money value of feeding-stuffs, as given by Dr. Wolff* for Germany for 1878.

*Except those in italics, which are American products analyzed under direction of Professor Johnson.

Comparing the poorer foods, such as straw, cornstalks, and inferior hay with a good standard food like the best hay or pasture grass, it appears that the great difference is that the former lack albuminoids, just what bran, oil cake, cottonseed cake, and especially fish, supply. One

* Fat and carbohydrates have, it is believed, similar nutritive functions, and it is assumed that 1 part of fat equals 2.4 of carbohydrates.

hundred pounds of the fish scrap made by Goodale's process added to 900 lbs. of the poorest hay would make a mixture equal in composition to 1,000 pounds of the best hay. Three hundred pounds of the same fish-food with 1,700 lbs. of oat straw would be equal to a ton of the best hay.

It is clear, then, that what our farming wants, to make stock-raising profitable, manure plenty and rich, and crops large and nutritious, is nitrogenous material for foods.

One of the cheapest, most useful, and best forms in which this can be furnished is in fish products. In proof of this we have the testimony of both extensive experience and accurate experimenting.

Experience in use of fish as food for stock.-Feeding cattle on fish in Massachusetts.

319. The earliest account which I have met of fish as food for domestic animals is the following extract from the Barnstable [Mass.] "Journal,” of February 7, 1833:

"Feeding cattle on fish.-The cattle at Provincetown feed upon fish with apparently as good relish as upon the best kinds of fodder. It is said that some cows, kept there several years, will, when grain and fish are placed before them at the same time, prefer the later, eating the whole of the fish before they touch the grain. Like one of old, we were rather incredulous on this subject, till we had the evidence of ocular demonstration. We have seen the cows at that place boldly enter the surf, in pursuit of the offals thrown from the fish-boats on the shore, and when obtained, masticate and swallow every part except the hardest bones. A Provincetown cow will dissect the head of a cod with wonderful celerity. She places one foot upon a part of it, and with her teeth tears off the skin and gristly parts, and in a few moments nothing is left but the bones."

The inhabitants of Provincetown are not the only people who feed their cattle upon fish. The nations of the Coromandel coast, as well as in the other parts of the East, practice feeding their flocks and herds with fish. The celebrated traveler, Ibu Batuta, who visited Zafar, the most easterly city in Yemen, in the early part of the fourteenth century, says that the inhabitants of that city carried on a great trade in horses in India, and at that period fed their flocks and herds with fish, a practice which he says he had nowhere else observed.

Experiment of Mr. Lawes, in England, with fish as food for swine. 320. In 1853 Mr. J. B. Lawes, of Rothamshead, England, reported several extensive series of experiments "On the Feeding of Pigs," in which were tested the effects of bean, lentil, Indian corn, and barley meals, bran, and dried Newfoundland codfish as foods for fattening and making manure. In speaking of the series in which the fish was fed with maize, barley, and bran in different proportions, Mr. Lawes says: "In the series where we have a comparatively