[14] Mr. Hearder, of Plymouth, affords a remarkable instance of the successful pursuit of science under difficulties. He lost his sight in his youth by an accidental explosion during some chemical experiments, but instead of being disheartened by that calamity, he has continued to pursue his investigations with unabated vigour, and has succeeded in throwing much light on many of the recondite properties of electricity, by admirably contrived experiments, which were conducted with unremitting perseverance at great expense. He has been in the habit of delivering lectures at the Plymouth Institution, and other Institutions in Devon and Cornwall; and those who witness the skilful manipulation of his experiments can scarcely suppose that he is blind. [15] This statement does not adequately represent the reduction in price; for each volume, sold at 5s., contained a volume and a half as originally published, besides Sir Walter Scott's notes; and the cheap volumes were illustrated with steel engravings. [16] If the number of sheets of paper used in printing these works were laid side by side, they would extend nearly _fifty thousand miles_! [17] "L'Art de la Lithographie;" par M. Aloys Senefelder, Inventeur de l'Art Lithographique. Munich, 1859. [18] Book of Ecclesiastes i. 10. Works on Chemistry. Class-book of Chemistry. BY E. L. YOUMANS. 12mo. 340 pages. Price 75 cents. Every page of this book bears evidence of the author's superior ability of perfectly conforming his style to the capacity of youth. This is a merit rarely possessed by the authors of scientific school-books, and will be appreciated by every discriminating teacher. While Chemistry is almost universally regarded by students as a dry and repulsive study (owing to the rigid and technical manner in which it is presented), Mr. Youmans' work will be found pre-eminent in clearness and simplicity of diction, by which the subject is made at once interesting and attractive. It is especially commended by the eminently practical manner in which each subject is presented. Its illustrations are drawn largely from the phenomena of daily experience, and the interest of the pupil is speedily awakened by the consideration that Chemistry is not a matter belonging exclusively to physicians and professors. _From_ PROF. WM. H. BIGELOW. The eminently practical character of the Class-book, treating of the familiar applications of the science, is, in my opinion, its chief excellence, and gives it a value far superior to any other work now before the public. _From_ DAVID SYME, A. M., _formerly Principal of the Math. Dept. and Lecturer in Nat. Philosophy, Chemistry, and Physiology, in Columbia College_. MR. YOUMANS: Dear Sir,--I have carefully examined your Class-Book on Chemistry, and, in my opinion, it is better adapted for use in schools and academies than any other work on the subject that has fallen under my observation.