rape-cake contains more frequently than any other description of cake the seeds of weeds. The experienced eye will find no difficulty in recognizing in rape-cake the seeds of mustard, charlock, and other weeds. Some of these seeds possess a disagreeable, bitter, or acrid taste, and possibly may possess poisonous properties.

I would direct special attention to the fact that rape-cake often contains a considerable proportion of mustard-seed. In Belgium, France, and Germany, where much rape is grown on account of the oil which its seed furnishes, the fields are often very foul with mustard; but as mustard itself is grown on account of its oleaginous seed, no care is taken to eradicate it, and hence it is that rape-cake contains frequently much of the expressed seeds of mustard. This admixture is injurious if the cake is given to fattening cattle in any quantity. Sheep do not appear to be affected so much as cattle by mustard. Rape-cake, which is rarely quite free from mustard, therefore, may be given with greater advantage to sheep than to cattle.

The fact that some samples of rape-cake are full of mustard and others comparatively free from it, perhaps accounts also for the differences of opinion which farmers who have tried rape-cake entertain respecting its feeding value. Rape-cake, free from foreign seeds and well kept, may indeed be a valuable and economic article of food; but there is often rapecake sold to farmers which contains so much mustard that it is difficult to decide whether the cake is rape or a mustard cake. Such cake should never be used for feeding purposes, for it is certain to injure the condition of the animals to which it is given.

Linseed-cake is manufactured in England; in America, France, Holland, Germany, Russia, Belgium, Italy, and other continental countries, and imported into England under names denoting the country in which they have been manufactured.

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English cake is generally preferred to all other varieties, and fetches usually a higher price in the market. However, much depends upon fancy of the purchaser: thus whilst in most localities English cake is preferred to American, I am told the latter fetches a higher price in Exeter market than English.

This circumstance led me to ascertain whether there was any real difference in the composition of two samples of American and English linseed, which were bought last season at Exeter, with a greater expenditure of £1 per ton for the American cake. Without mentioning the details of my examination, I will briefly state that both cakes were of excellent qualities, and that the differences in the composition were so trifling, that

both might be regarded, for practical purposes, to be identical. Neither in their chemical composition, nor in their physical properties, could any marked difference be detected which might account for the higher price paid for the American cake in Exeter market.

English cake, it is true, generally, though by no means always contains more oil than American or other foreign linseed-cakes, but the differences in the relative proportions of oil in various cakes are too inconsiderable to account for the higher estimation in which English or American cakes are held. The superior value of home-made, and also of most American cakes, I believe depends not so much on their chemical composition, as upon the condition in which the cake is found in the market. Good home-made cake, and most American cakes, are always dry and free from moldiness and rancid smell; they have an agreeable flavor and mild sweet taste, and for these reasons are more highly appreciated than other foreign cakes, which generally possess a more or less rancid smell and taste, and appear often moldy or damp. Moreover, on the Continent the extraction of the oil from the linseed is frequently aided by a degree of heat which impairs the flavor, and consequently deteriorates the value of the cake. On the whole, greater care is bestowed on the manufacture of English cake than on that of cakes imported from other countries. Besides, English cake is prepared only in a limited extent, and always finds a ready sale; no time is therefore allowed for the oil still remaining in the cake to become rancid. Foreign cakes, on the contrary, in passing through different hands before they reach their final destination, often attain a considerable age, which impairs the flavor and deteriorates greatly the value of the cake, especially if it is kept in damp places. Like all organic substances, oil-cake is subject to changes, which do not improve its qualities. The fresher it is the better it is adapted for feeding purposes.

Foreign linseed-cakes, with the exception of American cakes, are seldom so free from foreign seeds as English cakes, and this no doubt is another reason why home-made cake is more highly prized by the practical feeder. MUSTARD-CAKE.-Mustard-cake is imported into England from the Continent, and extensively used in the hop districts of Kent as an excellent manure. This is the only safe use to which it can be applied. But, as it is much cheaper than linseed or rape-cake, and resembles intimately rapecake, it is now and then mixed with this cake by unscrupulous dealers; and instances are on record that even pure mustard-cake has been sold as rape cake.

When mustard-cake or rape-cake, containing much mustard-seed, is made with cold water into a thick paste, and this paste is kept for about

six hours, it acquires the pungent taste and strong irritating smell peculiar to mustard-seed. This pungent taste and smell is caused by the volatile or essential oil of mustard, which is produced under the influence of cold water from myronic acid and myron, two inodorous and tasteless constituents of mustard-seed. Myronic acid is peculiar to mustard; myron resem bles in its chemical character albumen, and like all nitrogenized substances, gradually changes myronic acid in the presence of cold or moderately warm water and air into the essential oil of mustard. At the temperature of boiling water myron becomes coagulated, and in this state is incapable of changing myronic acid into essential oil of mustard.

Mustard-cake in a dry state has neither a pungent smell nor taste. It resembles, indeed, in its appearance, smell, and taste, rape-cake. If mustard-cake is kept, however, for some time in the mouth, it tastes bitter, acrid, and becomes more and more pungent, the longer it is kept between the teeth. On grinding, moreover, it gives a bright yellow powder, altogether different in appearance from powdered rape-cake. By these characters, and especially by the pungent smell which mustard-cake develops when mixed with cold water, mustard-cake is readily distinguished from rape-cake.

Neither mustard, nor rape-cake containing much mustard-seed, should ever be used for feeding-purposes, inasmuch as the pungent oil of mustard, which is gradually generated in the stomach of the beast fed upon such cakes, acts as an irritating poison, which may cause serious injury, and even death.

Not long ago a case of poisoning with mustard-cake was brought under my notice. A gentleman residing at Bibury, a village eight miles from Cirencester, Gloucestershire, lost three valuable beasts, which had been supplied with a small quantity of oil-cake, a portion of which was forwarded to me for examination. The day before the cake was given to them they were perfectly well; and after having eaten some cake, they became suddenly so ill that two died before the veterinary surgeon could administer an efficient remedy. The examination showed that the cake which caused this mischief was either altogether a mustard-cake, or contained a very large proportion of mustard-seed. There remained thus no doubt that the beasts died from the effects of the pungent oil of mustard.

As the formation of the essential oil of mustard is prevented by boiling water, and rape-cake often contains mustard-seed in a degree which cannot but exercise an injurious effect upon the health of animals, I would recom mend to mix all rape-cake with boiling water before it is given to cattle. By this simple means any injury which rape-cake containing mustard-seed

would produce, when not submitted to the action of boiling water, may be entirely prevented; but unless the water is in a perfect state of ebullition, it will fail to accomplish this desirable end.

In conclusion of these remarks on oil-cakes, I suggest to purchasers of cake to submit it to the following easy test:—

1. Examine a bit of cake as to its taste and smell; observe that it is fresh, and free from any moldiness.

2. Examine another piece with a common pocket lens. This examination will show whether the cake is a linseed or rape-cake, inasmuch as the form of linseed and rape-seed are widely different. Much more difficult is it to distinguish by the lens mustard from rape-cake.

3. Mix in a tumbler about 1 oz. of the cake, broken into small pieces, with 6 oz. of cold water. Good linseed-cake will form, under these circumstances, a stiff, agreeably-tasting jelly, without separating any water. Rape-cake will become much less gelatinous, and separate a yellowish or brown, rather bitter-tasting liquid. Mustard-cake likewise will become little gelatinous, and separate a brown liquid, which possesses the characteristic taste and smell of essential oil of mustard. Rape-cake fraudulently or naturally mixed with mustard-seed, under these circumstances will exhibit a similar behavior to that of mustard-cake, and by the degree of pungency of taste and smell when compared with pure mustard-cake, will afford means of estimating approximately the amount of mustard which the cake contains.

3. LEGUMINOUS SEEDS (Beans, Peas, Lentils, Tares, and Fenugreekseed).—The average composition of beans, peas, and lentils, as calculated from the analyses made by Horsford, Krocker, Einhof, Braconnot, and Boussingault, is represented in the following table:—

These analytical results, arranged in groups, yield the following average numbers:

No separate determination of woody fibre having been made, this number has been assumed in this calculation.

Still more recently, several kinds of beans, peas, lentils, and tares have been analysed by Dr. Anderson. The principal results of this analytical investigation are contained in the subjoined table:

It will be observed that all these leguminous seeds resemble each other so closely in composition, that for all practical purposes, the nutritive value of beans, peas, lentils, and tares in so far as this can be determined by analysis, may be considered identical.

The characteristic constituents of leguminous seed is legumin-a substance which resembles so intimately the cheesy matter or curd of milk, that it has received the name of vegetable casein.

Tares appear to be richer in legumin than the other leguminous seeds, which, on an average, contain as much of this flesh-producing substance as good oil-cake.

As far as the power of animals to lay on muscle is dependent on the nitrogenized principles contained in the food they eat, peas, beans, lentils, and tares are as valuable as oil-cakes, but as they contain much less oil, and are not so easy digested, these leguminous seeds are decidedly inferior to oil-cake as feeding materials. Compared with oats, barley, and other grain, peas, beans, lentils, &c., are much richer in muscle-producing mat