We perceive that Mr. Murray has advertised the second edition of Sir Humphry Davy's _Salmonia_, with the following opinion quoted from the _Gentleman's Magazine_: "One of the most delightful labours of leisure ever seen--not a few of the most beautiful phenomena of nature are here lucidly explained." Now, these identical words occur in our Memoir of Sir H. Davy prefixed to vol. xiii. of _The Mirror_, and published in July, 1829. A Memoir of Sir Humphry Davy appeared subsequently in the _Gentleman's Magazine_ of the same year, in which the editor has most unceremoniously borrowed the original portion of our Memoir (among which is that quoted above), without a single line of acknowledgment. He has, too, printed this matter in his largest type, while we were content to write and sell the whole Memoir and Portrait at our usual cheap rate. * * * * * Printed and Published by J. LIMBIRD, 143, Strand, (near Somerset House,) London; sold by ERNEST FLEISCHER, 626, New Market, Leipsic; G.G. BENNIS, 55, Rue Neuve, St. Augustin, Paris; and by all Newsmen and Booksellers.