ful agent. The effects of cold in diminishing the elastic power of bodies has been noticed before. It appears then, that temperature has a great effect in promoting the action of different bodies; and it is also apparent, that whilst it promotes the action of some bodies, it retards and prevents the action of others: therefore, this power in many cases produces opposite effects; and in order to obtain a just theory of its operation, we must be well acquainted with its effect upon bodies possessed of cohesion and those also which assume an elastic form, Erratum, col. 25, for" heat is obstructed," read "coloric is absorbed." (To be continued.)

ANSWER TO A QUERY, [Inserted in column 97, Vol. II.] MR. EDITOR,

A Correspondent in your 12th No. proposed this question: "As Oxygen forms a component of Water in the proportion of 85 to 100, why does not Water taste acid, since Oxygen is the principle of acidification?" I beg leave to inform him, that it is not always so; but is owing to the base with which it is combined, for in some instances it is also the principle of alkalization; nor does the proportion signify, for it can only combine in a ratio with the attraction of composition.

Melbourn, Feb. 1820.

uniformly attended to by the Essenes, a philosophical sect among the Jews: "Grace was said by the priest both before and after meat; they begin and end with praise to God, as he who bestows their food upon them." From hence we may conclude, that a custom so decorous and becoming, used both by Heathens and Jews, would not be unobserved or neglected by the pious disciples of Christ. It was attended to by our Lord. The sacred historian informs us, that when the Saviour fed the multitude, " he took the bread, and gave thanks," John vi. 11. Paul conformed to this custom, Acts xxvii. 35; and some are of opinion, that to this custom the apostle refers, when he says, "He that eateth, eateth to the Lord, for he giveth God thanks,” Rom. 14. 7. Doubtless, in this particular, the primitive Christians imitated Christ and his Apostles, and constantly, both before and after eating, expressed their gratitude, and solicited the Divine blessing.

St.

2. Your correspondent inquires, "Is this custom, which seems to be founded on the example of our Lord, the indispensable duty of Christians in the present day?" Certainly it is; for Christ hath "left us an example, that we should follow his steps;" and true disciples should imitate their Lord in all his imitable perfections. An eminent moralist justly observes, "When favours are received, grateful acknowledgments should be expressed." God liberally supplies our returning necessities, and gives us all

on our Food.

MR. EDITOR, IN perusing the 12th number of your valuable Miscellany, col. 97, I observe two Queries, by a correspondent, "On asking a Blessing on our Food." To which I send the following replies. Should they meet your approbation, their early insertion will oblige

Sir, your's, respectfully,
E. USHER.
Loughton, Essex, March 16, 1820.

1. "Whether this custom was in use among the primitive Christians, and if so, when and how was it practised?" Josephus speaks of this custom being attended to by the heathen priests, in the days of Ptolemy Philadelphus, king of Egypt. And in his Jewish war, he informs us, that it was a custom

obliges us to acknowledge his goodness, crave his benediction, and pray for grace duly to improve our many mercies: and an inspired writer exhorts us, that "whether we eat or drink, or whatever we do, to do all to the glory of God."

349

arrange our active powers, and all that lead to action, or influence the mind to act; such as appetite, passions, and affections. I do not mean to say, that the understanding has no influence on the determination of the will; it evidently has some little; for the will must have an object, and that object must be apprehended or conceived in the understanding. But the will is determined to action by the passions; for if there were no passionate feeling for the object presented to a person's view, there could be no act of the will in the pursuit of it, though he might fully comprehend it (that is the object) in his understand- | ing. From hence I infer, the will is determined to action by the passions. A. B. D.

Reply to a Query on the Earth's
Increase.

SIR,-Your correspondent Tyro, of Tetbury, vol. I. col. 1082, seems to be much concerned about the growth of the Earth: I have no hesitation in affirming there is no danger to be apprehended from an increase, either of its bulk or weight; which the following considerations will perhaps be thought sufficiently to prove. First, Matter cannot be annihilated, (speaking after the manner of men.) Secondly, Matter is capable of an infinite variety of modifications, as to its form, density, solidity, fluidity, animation, vegetation, and every other quality which it may possess. Thirdly, Matter is continually transmigrating from one subject to another; assuming, at the same time, a form, density, solidity, fluidity, animation, vegetation, &c. agreeable to, and partaking of the qualities of, the subject into which it is transformed. Thus is man as literally formed of the dust of the ground, now, as he was at his first creation; the very bodies in which our souls are kept, are nothing more than a modification of animal and vegetable matter; the vessels of the body, as physicians well know, transform the essence of animal and vegetable matter into chyle, blood, flesh, bones, &c. which is finally in its turn cast off, in evaporation, hair, nails, and other means; and is again succeeded by fresh matter as before. Very probably a knowledge of this fact gave rise to the ancient doctrine of transmigration.

350

If the above observations are correct, we must conclude that the Earth does not increase either in size or weight. If I should be asked for proof, I would answer, First, The fact as it is known to exist, is the best of proofs. Secondly, Philosophy requires no other proof than that it is most agreeable to reason; and is the most simple means by which the various phenomena relating to the transition of matter (according to human conception) can be accomplished. Thirdly, If the Earth did increase in weight or bulk, the balance of projection, gravitation, and attraction, would be destroyed; as the weight of an ounce will turn the scale when it is in equilibrio: for that system must needs be nicely balanced by the hand of Deity, that has been going so long without the least diminution of, or addition to, its impetus; or without deviating from its regular order in any degree. Again:-If new matter is brought to the earth in the composition of bodies, either animal or vegctable; I would fain know, from whence does it come; as matter is inert, and cannot possibly create or animate itself?

Much more might be said upon this subject, were it not an unnecessary intrusion on your pages. I think I have advanced nothing that is untenable, or incapable of further proof, if required. I need not say, that what I have advanced is equally applicable to all parts of animate or inanimate crea

tion.

If you will have the goodness to satisfy Tyro, by inserting these remarks in your Miscellany, you will greatly oblige,

Your well wisher,

Hilton, near Cambridge, Feb. 7, 1820.

ANECDOTE.

THEWSA.

353

354

ON THE METHOD OF PRESERVING
BIRDS.

[Inserted Vol. I. cols. 371 & 790.]

Liverpool, March 27, 1820. SIR, It was but a few days ago, when a friend directed my attention to a letter in your Magazine of November last, on certain methods of Preserving Birds, which from the nature of the subject, and from bearing the initials of my name, he concluded was my writing.

It is not my present intention of commenting on these instructions, nor indeed should I have noticed the letter at all, had not the Author chosen to cast a reflection on the state of the Birds in the British Museum; "too many of which," he says "are going rapidly to decay," and " a prey to myriads of animalculæ," (insects). This calls for a positive contradiction, for so far from such being the case, the Ornithological specimens in the Museum for the last six years, since the appointment of Dr. Leach, have been, and are, in as fine a state of preservation, and of systematic arrangement, as possible; and the watchful attention bestowed on them, is but a trifling portion of the benefits our National Museum has experienced from the talents and zeal of that excellent zoologist. Among other considerable improvements that have emanated from him, is the fitting up of a large and elegant apartment, containing the most perfect collection in existence of our native birds and quadrupeds, set up by the best animal preservers in the kingdom.

I trust, Sir, you will give this letter an early insertion; the article that has occasioned it has been generally attributed to me, who am perhaps the last person who should have advanced an assertion I have had so many opportunities of knowing is without the least foundation.

rate of somewhat more than 1000 miles per hour, in an eastward direction; and it is also supposed, that the atmosphere, by the principle of attraction, partakes of the same rapid motion, and consequently performs a similar revolution. The natural consequence of which will be, as we daily witness, that birds, balloons, &c., and in fact every thing floating in the atmosphere, is of necessity carried round with it, in its diurnal revolution. But does there not appear a difficulty in the application of this theory to the motion of ponderous substances, which are not naturally buoyant in air; but which are carried through it by an extrinsic force? Such for instance is a cannon-ball, which we will suppose to be projected in a westerly direction, at the rate of one mile in a second of

time; this motion is contrary to that of the Earth, over which the ball passes. The ball not being buoyant in the atmosphere, and yet completely detached from the Earth, is it not natural to suppose, that by the Earth passing from under the ball, during its flight, the extent of that flight would be necessarily increased, in an exact proportion to the motion of the Earth during the time? So, that instead of going merely a mile in a second of time, the motion of the ball, by the addition of that of the Earth, would be above a mile and a quarter in a westerly direction; while on the same principle, it would not exceed three-quarters of a mile in an easterly direction, in which the motion of the ball would be coincident with that of

the Earth.

The above would appear to be the natural consequences of the flight of a cannon-ball over the Earth, if uninfluenced by any other power. Matter of fact, however, I believe demonstrates the contrary to be the case; for a cannon-ball projected with equal force, will go exactly the same distance in a given space of time, to any point of the compass. Hence it is plain, there must be some power in nature, which effectually prevents what would otherwise be the inevitable result, of two detached bodies passing each other in a contrary direction, as in the case above described. I shall feel obliged to any of your philosophical correspondents, who will favour me with a satisfactory solution of this difficulty; and if the effect be ascribed to the