that he had chosen a branch of physics so well settled as that of light, and thought that he ought rather to have entered into some of the exciting phases of modern scientific controversy. Others complained that he dealt with the subject in so elementary a manner, and thought he ought to go into it with a profundity commensurate with his reputation, and such as would afford an adequate excuse for his leaving home and going so far away to instruct a foreign people. For we may just as well acknowledge that there was a great deal of narrowness and illiberality in the view taken of Tyndall's errand, and which was by no means confined to the laity. There was an ill-suppressed jealousy on the part of some of our scientific men, which made them captious in regard to the lectures, and which gave freight and currency to objections that from other sources would have been regarded as frivolous and unworthy of notice. It would have been far easier for Prof. Tyndall to have taken up some of the recent controversial topics, in which the public takes so deep an interest, and read a series of discourses that would have drawn crowds to his lecture-room, instead of encumbering himself with tons of apparatus, and bringing along experienced assistants to make his lectures thoroughly experimental and demonstrative for large popular audiences. But his choice of a subject, and his method of treating it, have been abundantly vindicated. He presented the leading principles of optics in a striking and impressive manner, and as connected and interpreted by the undulatory theory of light, with various lessons and applications in regard to the uses of scientific theory, and the motives of scientific research, which the topic was so well suited to enforce. Tyndall's American lectures form incomparably the best popular exposition of the wave-theory of light to be found in any language, and for this purpose it will long hold its place as a standard book. Accepting the public approval of the work for this purpose, as evinced by the several editions that have been called for. Prof. Tyndall has carefully revised it, made some important additions, and substituted new and superior illustrations, so that the edition which now appears, although faithfully presenting the lectures as they were delivered, has very much the aspect of a new work. He has prefixed to the volume a fine steel engraving, by Mr. Adlard, of Dr. Thomas Young, whose position in modern physics he holds to be only second to that of Newton, and in a full appendix of instructive notes and extracts he has incorporated the addresses of President Barnard, Dr. Draper, President White, and his own remarks, at the Tyndall banquet which followed the close of his lectures in New York. In his preface to the second English edition, now republished here, Prof. Tyndall remarks as follows of the object he had in view in preparing the American lectures: "I have sought to raise the wave-theory of light to adequate clearness in the reader's mind, and to show its power as an organizer of optical phenomena. From what has been recently written on such questions, it is to be inferred that the origin, scope, and warrant of physical theories generally, constitute a theme of considerable interest to thoughtful minds. On these points I have ventured, particularly in the second and third lectures, to state the views which my own reflections have suggested to me. To produce a systematic treatise on light was, of course, quite wide of my aim. My desire, rather, was to throw into a small compass an exposition for which I should have been grateful at a certain period of my own studies. I wished, in the first place, as the prime condition of all satisfactory progress, to clear the reader's mind of all indistinctness regarding elementary facts and conceptions, and to whet incidentally the desire for further knowledge. I wished, moreover, for the sake of that numerous portion of the community who are interested in the material results of science, to trace effects to their causes, by showing how such results receive their primary vitalization from the thoughts of men with no material end in view. The 'Summary and Conclusion,' which might be read as an introduction, is for the most part devoted to this object."
Facts and Fancies about Fish: The New York Aquarium. New York: D. Appleton & Co. Pp. 15.
This little pamphlet is Part I., No. 1, of a series of popular natural history monographs by Mr. W. S. Ward, naturalist of
