this hay and giving it to my cattle, I found that, so far from refusing it, they ate it with surprising appetite, always preferring it before the sweetest hay that had not in this manner been sprinkled with salt.”

Lord Somerville, in a communication to the Board of Agriculture, speaks in terms of high commendation of the benefit of salt applied to hay in fattening cattle." It is well known,” observes his Lordship, " that hay, mouldy from rain, is rendered palatable and remarkably nutritious to cattle, by simply strewing salt on the stack, at the rate of ten or fifteen pounds per ton, when making: equally notorious is it, that a sensible effect is hereby produced to the taste; that cattle will prefer it to better hay, well put together, and will demand, when fed on it, without injury to themselves, three times as much water; which circumstance alone accounts for that aptitude to fatten which is conspicuous in hay so salted. It remains to be proved how good hay, which had not spent its strength in premature fermentation, would bear such a quantity of salt as would invigorate the stomach, quicken the circulation of the blood, and excite in cattle a desire to drink largely. That it does bear it, and that the effect this hay has upon stock almost surpasses belief, we have ascertained. Some of our hay, lately in use, was of the first quality of sheep hay, the produce of rich and deep loam on a limestone bottom; it was put together without wet, and had twenty-five pounds of salt per ton sprinkled through a sieve, a greater quantity than has yet been used. In colour, flavour, and proof, it equalled any hay whatever; and satisfies us, that this or a greater quantity of salt may be infused into hay of the best quality, and with the best possible effect. In confirmation of these facts, we have also the authority of Mr Darke of Breedon, one of the most celebrated graziers in the kingdom, who has mixed salt with his flooded, mouldy hay, eight pounds of salt only to a ton, and declares that his Hereford oxen did better on it than others on the best hay he had, and that he was, and is, convinced, that the hay had all its good effect from the salt. Salt cannot be conveyed into the animal in a more effectual manner, than by sprinkling it on hay through a sieve, when in the act of putting together; for every particle is imbibed in the fermentation, without a possibility of waste."

Mr Young, in the Annals of Agriculture, also speaks highly of this practice. "We must beg leave," says he, "to recommend the salting of ricks. I am persuaded that few farmers are aware of the benefit arising from this practice, particularly in stacking in sultry weather. The salt preserves the hay from over heating and becoming mildewed: it may be put together greener than otherwise, without danger of firing. All kinds of cattle, &c. prefer inferior hay, thus managed, to the best that can be placed before them that has not been salted: the salt assimilates with the juices of the hay, and thereby prevents too great a fermentation. The proper way of using it is, in building the stack, to sprinkle the salt alternately between each layer of hay, in the proportion of 20lb. or 25lb. per ton."

The latter quantity was also used by Mr Dacre himself. His method of mixing it with the hay was as follows: He had a riddle, the meshes of which were one-eighth of an inch, and at every span as he advanced in the mow, he riddled twenty-four pounds of pure salt upon the hay per ton, estimating the ton by the acre. No bad effect, he adds, was seen during the sweeting of the hay. The cattle that fed upon it were healthy, in high condition, and far superior in appearance to cattle in the vicinity, that had not the benefit of salt. He observes, that hay should not be salted with foul or damaged salt; and that hay damaged by unseasonable weather, or hay well saved, must be made, housed, or stacked, perfectly dry, when salt is applied. Mr Varley, in his Farmer's Guide, also recommends the sprinkling of hay with salt. "Hay thus treated," says he, "is converted into a kind of salt marsh, which is the most wholesome land we have. The farmer of an inland country might nearly supply the place of a salt marsh, by giving his cattle salt amongst their food."

Salt has also been given with benefit to calves. Mr Wood of Ingatestone, Essex, says, that a calf-jobber, who had many sucklers which he could not sell to advantage, kept them; but being short of milk, he gave them oatmeal-gruel, by which he lost many of them, until he was recommended to put some common salt into the gruel; he attended to this advice, and did not lose another calf. By the Table of Mr Curwen, which we have given when speaking of the uses of salt to horses and cows, it will

be seen that he gave one ounce of salt per day at twice to his calves. We have seen it given to them in a fattening state with happy effects. Indeed, it frequently happens, that in the case of calves feeding on milk without the aid of any other food, the stomach becomes disordered, the animal loathes its milk, and does not increase in fatness. A quantity of salt dissolved in water, given under such circumstances, will restore the tone of the animal's stomach, by which it will take milk with greater zest, and increase proportionally in fatness.

Though a great quantity of salt given to hogs is considered by some to be injurious, in America it is occasionally given to them, to render them tame, and prevent their being lost in the woods. Mr Curwen gave salt to his hogs, by mixing it with steamed potatoes, on which he fed them. It is said, that in some places in Ireland, salt is sprinkled on every meal which is given to hogs, by which they are found to fatten in half the time they would otherwise require. Hogs that have access to coal-ashes are known to be very fond of a small quantity of the semi-incinerated parts of the coal. As there can be no nourishment in a mineral, especially in that state, the only object in taking it, we must suppose, is to stimulate the energy of the stomach.

Such are the general opinions and practices of the uses of salt to domestic animals, which we have endeavoured to condense and present in order. For a more general account of this subject, we must refer to the work under notice, where will be found ample details to compensate the reader's research, given to a length which our limits do not allow us to go. The work is professedly a compilation, and, as such, it does much credit to its author, for the mass of information on the uses of salt which he has collected together. He has drawn from the stores of a pretty extensive agricultural library, and presented in the volume before us, a fund of knowledge deduced from the opinions and practices of our most celebrated agricultural writers regarding the various uses of that ingredient.

Both analogically, as adduced from the habits of wild animals, and from the general current of that host of evidence which we have laid before our readers, we have been led cor

dially to acquiesce in the opinions so generally expressed in favour of salt as a condiment for animals. And it is a subject on which any one, even the most credulous, has a ready means of satisfying himself, by putting it to the test. It is not, like many schemes and improvements, which, to be profitably practised, or practised at all, must be done so on the large scale. In the case in question, it may be profitably practised by the carter who has only one horse, the private villager with his single cow, or the isolated cottager, whose whole stock of edible animals may consist in a single pet ewe, or, perchance, a solitary hog; in either of these cases, it may be practised as successfully as by the farmer with his thousands of sheep, his hundreds of cattle, his scores of horses, or his well stocked piggery.

The greater part of the experiments and general usages which we have stated, were made and practised when the price of salt, fettered by a heavy and impolitic tax, rendered the using of it very expensive; but now that salt can be purchased at such a low rate, it becomes in an eminent degree accessible to the uses of the agriculturist. Should it be theoretically contended, that though salt does no harm to the animals to which it is given, it is not thought to possess those properties which have been contended for it, and that it is not of that advantage generally, which would compensate the expense and trouble of using it, we would say that every farmer may in a very simple manner satisfy himself: Let him take any number of his sheep, cattle or horses, of the same breed, which in every respect receive the same food and treatment, and give to one portion of them salt, while the other portion of the same animals receives none, and in a short time he will be able to judge for himself, whether the use of salt is of such advantage in the food of his live stock as to merit its general adoption.

ON THEORIES OF POPULATION.

The Law of Population; a Treatise in Six Books, in Disproof of the Superfecundity of Human Beings, and developing the Real Principle of their Increase. By MICHAEL THOMAS SADLER, M. P. 1830.

IT being assumed that each pair added to the human race has an equal power of propagating the species, and it being found that, under the common law of mortality, communities or countries can add to their numbers, it is contended that the human race has a power to increase in proportion as their numbers increase; or, in other words, to increase in a geometrical ratio. If the inhabitants of a country shall be found to add in each year, or other period, one-hundredth part, or one-thousandth part, or one ten thousandth part, to the numbers existing at the preceding year or period, and this increase shall be constant, then it is correct to say that the increase is in a geometrical ratio. The arithmetical questions with which all are familiar, relating to the increase of money at compound interest, furnish examples of the geometri cal ratio of increase, and of its numerical effects, when the series is sufficiently extended. A penny put out at interest, at the birth of our Saviour, would, at 5 per cent. simple interest, have increased, at the present day, to 7s. 84d.; while, if put out at compound interest, it would have amounted to a sum equal to more than a million of times the bulk of the earth of gold.

The precise power of man to increase in numbers may be determined, either by observing the actual increase of the inhabitants of a country under circumstances favourable to the increase of their numbers, as in newly settled colonies, or by reasoning from observed data on the rate of mortality, and the number of the born in different countries.

Assuming that the number of births to each marriage is 4, which nearly accords with the observed fecundity of marriage in the temperate regions of Europe; that the age of marriage is 20 in both sexes, which is a possible supposition; that the law of mortality is what registers now show it to be in England ;