If we refer the cause to the decifion of common fense, and the natural principles of equity, this right will be no lefs evident." In this various world, different men are born to different fortunes : one inherits a portion of land; he cultivates it with care, it produces him corn and fruits and wool: another poffeffes a fruitful mind, teeming with ideas of every kind; he beflows his labour in cultivating that; the produce is reafon, fentiment, philofophy. It feems but equitable, that a fair exchange should be made of thefe goods; and that one man fhould live by the labour of his brain, as well as another by the sweat of his brow."

This point being established, it follows, that whatever can be afferted with truth concerning property in general, may fairly be applied to this particular kind of property.'

Having briefly but firmly established the natural right, our very fenfible Author proceeds to fhew that literary, as well as other kinds of property must be exclufive: that is, no perfon , whatever can have a right to enjoy the benefit of this property, except the author, and thofe to whom he affigns over that right. An author having the fame natural right to his compofition, as the poffeffor of lands to the fruits which they produce; no other man can have any claim to the profits arifing from the former, more than to thofe arifing from the latter. To take poffeffion of any work, for any purposes which interfere with the intereft of the author, farther than he himself or his affigns affent to it, is, on the principles of natural law, no lefs an invafion of property, than that of plundering a man's granaries or his coffers.'

From hence it follows, that the right of property including, in general, a right to retain as well as ufe thofe things which are the fubject of it,-the property of any literary work, with all the advantages it may produce, must remain with the author, till he voluntarily refigns it. That feries of ideas and words, continues Dr. E. which conftitute his work, is in itself an object of property, entirely diftinct from the book in which they are written. And out of this right arifes another; that of multiplying copies by tranfcribing or printing; for the work being his own, he may make what use of it he pleases. Thefe rights no other person can be at liberty to appropriate to himself, without the exprefs or tacit confent of the author. And no act ought to be conftrued into a renunciation of his rights, which he himself does not evidently intend as fuch.

That the act of publication ought not to be understood in this light, may be inferred from the general principles of equity. For, "If a man's ideas are his own while floating in his brain, it would furely be very hard to be deprived of all right to them, the moment he turns them to any profit either to himself or others; as unreafonable, as if the farmer were allowed a property in his corn and grass while growing in his field, but denied it whenever he brings them to market."

But this matter requiring a more particular difcuffion, the Writer pursues the argument, till he obtains a complete victory over those who have ventured to maintain the strange notion that

when

when an author parts with a copy of his work, he must of neceffity part with the ideas and expreffions, that is, with the compofition itself as well as the book which contains it, to the purchaser; and that therefore the purchafer, having a full poffeflion of the com-pofition, muft have a right as well as a power to ufe it for any pur pofe he fhall think proper, and among the reft for that of multiplying copies; unless in the fale an exprefs agreement is made to the contrary."

In the conclufion of the answer with which our Author has honoured these abfurd affertors of a doctrine which looks with fo mifchievous an afpect toward the interefts of learning and learned men, he draws the following juft inference :

The inference which ought to be drawn from the neceffity which an author is under to put his right of multiplying copies into the power of every purchafer, in order to make any advantage of his work, is, not that the act of publication conveys a right which he never meant to communicate, and for which the purchaser gives no equivalent; but that government ought to fecure it against the invafions of those, whofe private intereft may fo far blind their judgment, as to lead them to mistake power for right.'

On the whole, Dr. Enfield fully eftablishes the natural right of authors to their own works; and fhows, that upon the plain and fundamental principles of property in general, the writer of any work has an exclufive property in it, at least as long as he lives; and that no person whatever can have a right to multiply copies of it, or by any other means appropriate to himself any part of the profits arifing from it, without the confent of the author.'

The Obferver now proceeds to examine the objections of thofe who deny the right of authors to perpetual property in their own works; and, in our judgment, he has given them a complete refutation.

Among other confiderations, the main question, with respect to the manner or degree in which public utility might be effected by the perpetual fecurity of copy-right, is not overlooked; and 'we think, with our Author, that the general intereft requires, rather than forbids, the legal fecurity of the rights of authors, as well as of all other claffes of men.

The most common, we might fay vulgar objection against the perpetuity of literary property is grounded on an idea that it would be injurious to the Public, by encouraging a monopoly in the fale of books, which would raife the price of them to an exorbitant height; and (as Dr. E. farther obferves) the odious appellation of monopolizer has been freely, though very improperly, beftowed upon authors, and the bookfellers whom they appoint their affigns.'

This argument, like the reft that are made ufe of by the enemies to copy-right (the Vandals of the prefent age) is alfo

• Swift.

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clearly invalidated, and the ingenious Obferver concludes the whole with the following fummary view of what has been advanced in the courfe of his investigation of this important fubject:

The fum of the preceding obfervations is this. The right of authors to the exclufive poffeffion of their own works is founded in nature; and unless any fufficient caufe appears for depriving them of it, ought to be fecured and guarded by law. To grant them this fecurity, is neither impracticable in the nature of the thing, nor inconfiftent with the interests of the Public. The inconveniences which are apprehended from a perpetual exclufive right, are trifling, and in a great measure imaginary. The advantages which would arife from the encouragement which fuch a fecurity would give to philofophical and literary parfuits, are obvious and important. Since no good reafon can be affigned, why authors fhould be deprived of their right of property, they have a juft claim upon government for protection and fecurity in the enjoyment of this right. The interefts of the Public, inftead of oppofing, concur with this claim. On the fame principles, therefore, that a perpetual right to any other kind of eftate, real or perfonal, is fecured to individuals, an author may reasonably expect that his property in his own work fhould be fecured to him and his pofterity. Such fecurity is, by no means, at prefent enjoyed. The provifion which hath been already made for a temporary fecurity, in the ftatute of Queen Anne, and the favourable attention which is at prefent paid to this fubject by the Legiflature, do however afford encouragement to hope, that authors will at length obtain a legal grant of perpetual copy-right: a grant, which, if the reafoning in the preceding pages be juft, they have fufficient ground to requeft. When authors defire permiffion to communicate their thoughts to the Public with freedom on every fubject which is of importance to individuals or fociety, and the fecure poffeffion of the fruits of their own genius and labour," they afk nothing of government, but what every Englishman hath a right to expect from it, LIBERTY and PROPERTY."

Dr. Enfield's performance was publifhed, if we rightly recollect, fome time before the mifcarriage of the Bookfellers' Bill, in the laft feffion of parliament. The worthy Author, no doubt, from his generous concern for the honour and intereft of science and literature in this country, had conceived hopes that a different fate would have attended that neceflary application for legiflative protection; and, indeed, after the bill had fuccefsfully paffed the Commons, it was natural to conclude that our NOBLESSE would not have manifefted a lefs liberal and generous difpofition toward a caufe in which, not merely the intereft of a set of traders was embarked, but the welfare of that order of men, who, by the fuperiority of their talents, and acquirements, feem to have been fet apart by Providence, and by the common confent of Society, for the delight and inftruction of their fellow mortals :-in return for which they certainly merit from us every thing that gratitude and generofity can infpire.

ART.

ART. VII. CONCLUSION of the Account of Dr. Priestley's Experiments and Obfervations on different Kinds of Air: From our Review for Auguft laft, p. 136.

THE

HE fecond part of this ingenious work contains an account of the Author's experiments and obfervations made in the year 1773 and the beginning of 1774. It is divided into eight sections, in the firft of which the Author treats of a new fpecies of factitious air, or permanent vapour, not condenfable at leaft by cold, which he calls alcaline air; as it is extracted from spirit of fal ammoniac, or the common volatile alcaline falt of that name, by means of heat. These fubftances however were foon found to furnish a confiderable quantity of fixed air, mixed with the alcaline air. The Author was afterwards led to a method of procuring the latter in a pure ftate, as well as more plentifully and commodiously, by putting the ingredients used in the production of the cauftic volatile alcali (viz. fal ammoniac and quicklime), into a thin vial, to the mouth of which a bent tube is fitted; through which, on holding the vial over the flame of a candle, large quantities of this permanently elaftic fluid will pafs, and may be received in a veffel filled with quickfilver, ftanding inverted in a bafon of the fame fluid. Here it will remain in the form of a transparent and permanent air, and is in a fituation to afford opportunities of afcertaining its qualities and relations to a variety of other bodies. We fhall briefly mention a few of them.

Water readily condenfes and imbibes a very large quantity of this alcaline air; and when fully faturated with it is converted into a volatile fpirit of fal ammoniac, much ftronger than any that the Author had ever feen. On mixing this new air with the acid air mentioned in our former article, [Auguft, p. 146.] the Author conceived that, being of oppofite natures, they might compose a neutral air, and perhaps the very fame fubftance as common air. On trying the experiment, however, a beautiful white cloud was formed on the admixture of the two vapours: the quantity of air began to diminish, and when the cloud fubfided, it was found that both thefe hitherto elaftic fluids had condensed each other, and united into the form of a folid white falt, which was found to be the common fal ammoniac.

The falt thus produced immediately deliquefces in the com mon air; but in a very dry and warm place it almoft wholly evaporates in a white cloud. It is only thus volatile, however, when there has been more than a due proportion of the acid or alcaline air in the compound. In this cafe, the smell of the falts is extremely pungent, and very different from each other; being manifeftly acid or alcaline, according to the prevalence of either of thefe airs refpectively.

REV. Nov. 1774•

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It

It may appear fingular, that when nitrous air was mixed with alcaline air, though a whitifh cloud appeared, no neutral falt was produced; for on admitting water to the mixture, it was found that the two vapours did not unite, and form a tertium quid, as in the preceding inftance; but the water effected a feparation, prefently abforbing the alcaline air, and leaving the nitrous air poffeffed of its peculiar properties. These circumftances illuftrate and confirm the obfervations we made on the nature and conftituence of nitrous air in our former article ; where we fhewed that the union, between the acid and the other principle that conftitutes nitrous air, is so strong, that though nitrous air be admitted to, and long agitated with a folution of fixed alcali, or with lime-water, the acid contained in it will not be affected by them, unless common air be admitted. This laft mentioned fluid, according to the Author's ingenious theory, feparates the phlogifton from the nitrous acid; and thereby leaves the latter at liberty to unite with the water, alcaline falt, or other body presented to it.

On the mixture of fixed with alcaline air, ammoniacal chryftals were formed; which fhewed that the volatile alcaline falts of the fhops owe their folid and chryftaline form to the union of the volatile alcali with the fixed air, which proceeds from the fixed alcaline falt employed in the process.

In the second section the Author profecutes his observations en common air diminished, and made noxious, by various proceffes. His fubfequent experiments all tend to confirm his original hypothefis;-that in all these proceffes the air is rendered noxious by being overloaded with phlogiston.

The probability of this hypothefis will appear from an enumeration of fome of the proceffes which produce this effect on the air in which they are carried on. These are, the respiration of animals, the burning of candles, putrefaction, the mixture of nitrous air, the accenfion of Homberg's pyrophorus and of gunpowder, the fumes of liver of fulphur, the effluvia of paint, and thofe proceeding from a cement made of turpentine and bees wax, &c. All these proceffes agree in this one circumstance, that, in every one of them, phlogiston is let loose or feparated from thefe bodies; and is therefore probably the true cause of the injury which the air receives from them.

With regard to the manner in which the air is diminished, at the fame time that it is rendered noxious, by being overcharged with phlogifion; the Author conjectures that this principle, having a greater affinity, than fixed air has, to fome of the conftituent parts of common air, precipitates, or feparates from the latter the fixed air contained in it; and that to this precipitation the diminution of common air, rendered noxious by thefe procefies, is, in part as leaft owing. He afterwards fhews

that