The following extraordinary advertisement appears in The Country Journal; or, The Craftsman, Saturday, 18 July 1741 [Issue 785]. Although no copy of The Publisher’s Magazine is listed on ESTC, this "Society" did publish nine works.
To the Authors and Proprietors of Manuscripts, or other Copies design’d for the Press.
The Booksellers in general having the Unhappiness to lie under the Imputation of making Properties of learn’d and ingenious Men, and enriching themselves by the Fruits of their Study and Labours, whilst they allow them but scanty Premiums, and make use of all Artifices to deceive and Impose upon them, to the great Discouragement of Learning and Detriment to the Publick, who are thereby deprives of many valuable Pieces; in order to remove these or any other Prejudices, several Booksellers have form’s themselves into a Society, and offer the following Proposals to all whom it may concern.
1. That they will give ready Money to any Author or Proprietor of a Work which shall be approved of by two Persons of Judgement to be nominated one by the Author, the other by the Society, who shall also fix the Price to be given, on the Author’s conveying to the said Society his Right and Interest in such Copy.
2. That if the Author chuses not to part with his whole Interest in the Copy, and had rather wait the Event of its Sale, he shall receive the full Moity of the Profits arising from its Sale of the first and all future Editions of it, freed of all Risque, (the Expenses of Paper, Print, and other incident Charges, being first deducted) the other Moity to vest in the Society for the Hazard they will run, the Money they must expend, and for their Skill and Care of Management &c.
3. That the Paper shall be bought at the best Hand, the Work printed on the neatest Types, at the Rate Booksellers pay for both, and proper Vouchers procured to justify such Payments; and none but Persons of Credit, either Stationers or Printers, to be dealt with; and the Rates of Publication to be the same as Publishers usually reckon to Booksellers.
4. That all Pamphlets, from three Sheets (which are usually sold for Six Pence) to books of any Size or Price, shall be received if approved, on and Subject in the whole Circle of Learning; nor shall Political Pieces be excluded on either Side of Questions, whee not offensive to good Manners; for one establish’d Rule of the Society will be, not to be of any Party themselves, but to observe a strick Impartiality; and Names to be conceal’d, and the utmost Secrecy obcserved, if required.
5. That a reasonable Price shall be paid for such small Pieces as will not make three Sheets as above, in Order to be inserted in a Twelve penny Pamphlet, to be publish’d under the Title of the Publisher’s Magazine, by which Means the Publick may receive a curious Miscellany, in one, two, or more Volumes annually, and many beautiful small Pieces will be thereby preserved, and handed down to Posterity.
So many Advantages will accrue to Authors from these Proposals, besides the Security of the Copies from Piracy, (as the Society will be able to make Reprisals on such as shall invade their Property) that no more need be said on that Head.
And to the Publick in general this Design will be no less advantageous, as it will be the Means, at an easy and reasonable Rate, to bring to light many curious Pieces in every Branh of Science.
Gentlemen therefore who incline to take Advantage of and encourage this Undertaking, are desired to apply to James Crockatt, at the Society’s-Office in Fleet street, near St. Bride’s Church; or to Messieurs Osbourne and Smith, in Grey’s-Inn.
The said Messieurs Osbourne and Smith gives ready Money for any Library or Parcel of Books.
This advertisement re-appeared one week later, in The Weekly Miscellany, Saturday, 23 May 1741, but James Crockatt and the Mr "Smith" disappear, leaving only Thomas Osbourne to "transact the necessary Business."
This second version of the advertisement was reprinted in The London Daily Post and General Advertiser of 25 May, but on 10 June Crockatt and Smith reappear. On 13 and 27 June the advertisement is reprinted (in The Weekly Miscellany ) and the first of the titles "Publish'd, By the Society of Booksellers for promoting of learning." Another eight followed within the year, then nothing.
The full list of titles, in alphabetical order, is:
 Anon., The Christian Philosopher
 Anon., An Essay on the Divine Paternity, or, God the Father of Men
 Robert James, M.D., Proposals for Printing a Medicinal Dictionary [ESTC explains that A medicinal dictionary was published in three volumes, 1743-45].
 Robert James, M.D., A New Method of Preventing and Curing the Madness Caused by the Bite of a Mad Dog
 John Kelly, The Levee. A Farce
 James Nihell, M.D., New and Extraordinary Observations Concerning the Prediction of Various Crises by the Pulse
 Benjamin Parker, The Divine Authority of the Scriptures Philosophically Prov’d
 Charles de Saint-Yves, A New Treatise of the Diseases of the Eyes
 J. Shortess, Harmonic Architecture. Exemplified in a Plan, Elevations and Sections, &c. of a Building
I wonder what reflections can be made on the sort of manuscripts that were being held up by the "Imputation" that "Booksellers in general" were "making Properties of learn’d and ingenious Men … enriching themselves by the Fruits of their Study and Labours" while offering "but scanty Premiums" and using "all Artifices to deceive and Impose upon them"?
To me, the publication of this "Imputation" is more interesting than the titles this learned Society published; that, and the fact, that Thomas Osbourne was spruiking for manuscripts by acknowledging such criticisms. Advertisements like this tell us a great deal about the Trade in mid-1741 (at much the same time that Eliza Haywood was trying to establish herself at the Sign of Fame in Covent Garden).