character of his book, show mental unsoundness, and suggest that the mind's organ is not in a proper condition. One thing is certain: the maker of such a book is not a fit man to be in charge of educational interests. If he is beside himself, that ends it; if not, the case is still worse: the Board of Education should have granted him leave of absence, and sent him away to recruit.
In his contribution to the "International Scientific Series" of a volume on modern chromatics, Professor Rood has filled a gap in the scientific literature not only of this, but also of European countries. There was wanted a well-executed popular treatise on the science of color for general readers, in which they will find a familiar and satisfactory explanation of chromatic phenomena as they are now interpreted, and as illustrated in the aspects of nature and in the applications of art.
Professor Rood was asked to prepare such a volume for this series because he possesses in an eminent degree the qualifications necessary to do justice to the subject. In the first place, he was specially prepared to undertake it by his education and training as an experimental physicist. At home in this general field of research, with an aptitude for subtile and refined investigations, he has always been particularly interested in this line of inquiry, and has attained a European reputation as an authority upon the subject. From this point of view, probably, no man was so well equipped to make an instructive volume on chromatics that should be fully up to the times as Professor Rood.
But he possesses another qualification which is no less important for the work. He is himself an artist, with both enthusiasm and a true genius for the profession, and who has devoted much time to drawing and painting. His sketches are prized by many who are so fortunate as to possess them, and it is well understood that, if he had chosen to devote himself to it, he would have attained preeminent distinction as an artist. This combination of scientific knowledge with practical experience in the art of managing colors could not fail to be of great advantage. Numerous questions and problems relating to chromatics which are interesting and important to artists came before him, and were elucidated with such skill and useful results that he was called upon to give lectures, explaining his views, before the art classes at the New York Academy of Design.
When solicited to prepare the present volume, Professor Rood replied that he was not a book-maker, and had no inclination merely to compile or to write a volume upon the science of color. He said that to make such a book valuable in the present state of the subject would involve a very considerable amount of scientific investigation in clearing up numerous points to get the work in anything like satisfactory shape. For these researches time would be necessary, which would inevitably delay the publication. The volume was prepared under these conditions, so that, in a very important sense, it is a new work. Every chapter of it bears witness to the patient and painstaking solicitude of the author to make his statements clear, valid, and complete. A consultation of his index will show to how large a degree the volume is original. Only results and explanation are given in the text, and those who care to go over the experimental demonstrations by which they have been reached will consult the scientific periodicals in which the descriptive papers are to appear.
Professor Rood, as we have intimated, declines to classify himself as a book-maker, and does not seem to have ever been troubled in the slightest degree with the ambition of authorship. He has written many technical papers for scientific journals, which may be thought rather a poor apprenticeship for getting up a popular book. But he has attained a degree of excellence in the literary art of his book which is not a