The author of this work has designed it for the use of teachers and scholars. A large number of simple experiments have been added, with notes relative to the work. It is the primary book for school use. _A Most Important Work of General Interest_. *The X Ray; or, Photography of the Invisible and its Value in Surgery* By WILLIAM J. MORTON, M.D. Written in collaboration with EDWIN W. HAMMER. 1 volume, 12mo, cloth and silver, 75 cents; paper, 50 cents. Everyone has been waiting for this work to give full information of Professor Rontgen's marvellous discovery. The work explains in clear and simple style how these extraordinary pictures are taken through solids. Full description is given of the apparatus used, and the text is profusely illustrated with half tone illustrations giving fac-simile copies of the pictures taken from the negatives of the author. The subjects are varied. *The A B C of the X Ray*. By WM.H. MEADOWCROFT. 1 volume, 12mo, cloth and gold, 75 cloth; paper, 50 cents. The first primary work on the subject. A book for the people. The author of "A B C of Electricity," showed clearly in that work his ability to explain a technical subject for the laymen who know nothing of scientific terms. He has written this work about the X Ray in his usual clear and simple style, and a wide circulation of this useful book is assured. The texts of the author is beautifully embellished with fine engravings, and nothing is omitted that will give the public a clear knowledge of this remarkable discovery of Prof. Rontgen. The public would do well to secure both of these important works. *The Art of Cooking by Gas*. By MARION HARLAND 226 pages, 12mo, paper, 50 cents; cloth, 75 cents. A timely work by a recognized authority. This new book shows the economy, cleanliness and comfort of cooking by gas There are nearly 1000 recipes which are excellent. This valuable work will save its price many times to all housekeepers. _Any of the above books sent, postpaid, on receipt of price_ End of the Project Gutenberg EBook of Klondyke Nuggets, by Joseph Ladue