ratory experiments: and certainly in this respect America has little to fear from importations of "crumbs." The laboratories of the Stevens Institute of Technology, of the Lawrence Scientific School, of Columbia College, of the University of New York, and others, bear faithful witness to thorough work, and to real advances in the most delicate researches of physics. It must be remembered, too, that great works of analysis are not plenty in any country, and we think that the masterly works of Ferrel, on the theory of the tides, redeem America from reproach for 1874 at least.
The "Report of the Committee on the Preservation of Forests" follows, and from it we learn that this important subject is now before Congress in a proper form, and that we may reasonably hope for some action from that body.
The Association is divided into two sections, A and B, the first of "Mathematics, Physics, and Chemistry," the second of "Natural History," and we can judge of the attention given to the various subjects by noting the number of papers devoted to each.
Thus we find for Mathematics, one; for Astronomy, three; for Physics, eight; for Chemistry, eight; for Statistics, one. This completes the work of Section A. In the section of "Natural History" we find for Geology, eleven papers; for Paleontology, one; for Botany, four; for Zoölogy, twelve; for Anthropology, two.
It cannot fail to be noted that on the whole this volume of 378 pages is a decided improvement on its predecessor of 669 pages, particularly in the character of the publications printed. The printing committees seem to have exercised a careful scrutiny of the work put before them, and their selection has made the volume not uncreditable to American science.
We had not intended to notice in detail any of the separate papers, since they are all to be seen in the volume itself, and since very full reports of them were published by the New York Tribune during the time of the meeting; but it is impossible to avoid calling attention to a paragraph in a paper by Dr. Asa Gray, the great botanist of Cambridge, on the growth of the trunks of trees. The question was raised as to whether a tree in growing expanded its main trunk vertically in those parts once formed; experiments were made to determine this point by Dr. Gray, and the experiments and theories of various correspondents are analyzed by him. Of one he says:
[This] correspondent, "who has read in the older books on the structural botany a good deal more than there is any foundation for, about a collum, or collar, between the root and the stem, and who states that the wood is here of horizontal instead of vertical fibres, or cells, suggests that the trunks lengthen at their base only, and by the increase of these horizontal wood-fibres, formed one above the other, at the level of the ground. Now, in the first place, this supposed collar was only between the primary root and stem of a seedling; so that only trees raised from seed could be lengthened by its growth, not those originated from suckers, layers, or cuttings. Next, trunks lengthened in this way would come to have the butt-log composed of wood with horizontal fibres, which I think nobody ever saw. And, finally, there is no such collar, even in the seedling, with horizontal fibre, interposed between the root and stem."
We quote this to show that in some instances botany is more than an exact science—it is a precise one.
The Maintenance of Health. By J. Milner Fothergill, M. D. 366 pages. New York: G. P. Putnam's Sons, 1875. Price, $2.00.
This book is, in the author's first and last words, "a medical work for lay readers," "writ out of great good-will unto my countrymen." The book is divided into thirteen chapters, with the salient points summed up at the end of each in a list of propositions. The first chapter treats of health, what it is, and how maintained laying down many propositions, among which are that there are different types of health, and that bodily and mental health must go hand-in-hand. The next three chapters treat successively of health in youth, or the period of growth; health in adult life; and health in old age, or the period of decay. Chapter V. discusses the quality, quantity, and properties of food and clothes. Chapter VI. is given to stimulants and tobacco, in which the author uses these propositions: "Alcohol is a re-
