matician on the part which the imaginative faculty bears in scientific labours, he expressed himself to the effect that by far the greater number of mathematical truths are obtained, not by deduction, but through the inventive or imaginative power, and in this he had a view even to the properties of the triangle, the ellipsis, &c., which is saying little else than that the mathematician as well as the physicist can do nothing for his science without artistic endowment." We have selected the foregoing as a sample of the Baron's ideas, and we doubt not that most of our readers will thoroughly agree with them. The other papers are many of them of exceeding interest, and make the work a most interesting and valuable one. 1 25 1 50 DISEASE GERMS.* THE second edition of this important work has appeared, and it demands first of all, we may say, the only book of its kind in our language, and it is written by a man who must unquestionably be considered the first microscopic observer in the world; for he is one who has gone on steadily with his observations for a considerable number of years, and he is the only one who has worked (we use the word advisedly) with the highest microscopic powers, the and of an inch. Now from these circumstances alone considerable attention should be given to his writings. But when we further regard him as a professor in a vast public school of medicine, and as the author of an admirable manual of microscopic enquiry, we find ample testimony to his high character as an observer and a teacher. The views which the author lays down in this volume may in some cases be incorrect, though we do not say so; but assuredly they must be regarded as sound, till some one, with equal microscopic powers and experience, comes forward to demonstrate the contrary. The book is, in fact, an expansion of the Radcliffe lectures which Dr. Beale delivered a couple of years since, at Oxford; and the views it sets forth are given clearly, and while without that emphaticism which so readily suggests inexperience to the critical reader, they are nevertheless put forward as the strong and serious expression of opinion of one who, while he is ready to be corrected, is nevertheless hopeful of the truth of his opinions. The first few pages contain a stinging assault on some of the more recent investigators or rather writers and lecturers on the important subject of this volume. In this we fancy the writer has gone out of his way to take up the consideration of views and opinions which were not considered by the public as of more than a passing interest. We think, nevertheless, that Dr. Beale's defence of the late Dr. Budd is both well-timed and in good taste, which of course we cannot say for the views which he opposes. Bioplasm appears to us a very good term, and we think that Dr. Beale has much in his favour as he traces its growth. But "Disease Germs; their Nature and Origin." By Lionel S. Beale, M.B., F.R.S., Physician to King's College Hospital. Second Edition. London: J. & A. Churchill, 1872. we think that it is yet almost too early to consider as decided the question as to how contagiousness arises. We ourselves imagine that there is more to be said in favour of the fungous origin of disease, though in certain cases it appears almost impossible to trace the connection between the disease and living contagious organisms. But unquestionably, if such are to be found, they will be found by Dr. Beale and those who work under similar conditions; and they have not yet been discovered in particular cases. He believes, so far as we can see, that diseases are caught by the introduction of certain matter of an organic character, but not of the fungoid or algal nature. And, furthermore, he believes that these organisms, which are exceedingly minute, have not always existed, but have been called into life by the possible absence of hygienic care, which is too common among all large populations, and that they may be eventually banished after a couple of generations. It is this question which the book undertakes to deal with, and which is treated of lengthily in 450 pages of excellent type, accompanied by 28 plates, in three colours, of the principal subjects, which the author thinks help to illustrate the subject. Altogether the book is an excellent one, written in a healthy, clear, and forcible style, and containing plates which find their equal in no microscopical publication on this side of the Channel. THE HALF-HOURS ON THE SHORE.* THE love of natural history has now become so prevalent, at least among purely English readers, that we hardly meet a family at the sea-side, one of whose members has not some little knowledge of the wonders of the deep. Now, of course, this love of marine zoology is being vastly increased by the existence of the valuable Aquaria at the Crystal Palace and at Brighton. Still, however, notwithstanding the amount of admirable works on the subject, more especially the excellent treatises of Gosse and others, there was wanted a cheap form of book with good illustrations which should give a clear account of the ordinary creatures one meets with on the sands and in the rock pools. The want no longer exists, for the excellent little manual that now lies before us embraces all that could be desired by those who are entirely ignorant of the subject of sea-side zoology, while its mode of arrangement and woodcuts, which are carefully drawn and admirably coloured, combine to render it both attractive and useful. It is, as its name implies, divided into a number of chapters called half-hours, and which deal with the following subjects:-The Waves; Preparations; Sea-weeds; Sponges; Sea-worms; Corallines; Jelly-fish ; Sea-anemones; Sea-mats and Squirts; Sea-urchins and Star-fish; Univalve Shell-fish; Bivalve Shellfish, and lastly Crustacea. Under these separate headings are given clear and accurate accounts of the several groups which are abundantly figured in 148 cuts. Finally the book is excellently printed in large clear type. • Half-Hours at the Sea-side; or, Recreations with Marine Objects. By J. E. Taylor, F.G.S. London: R. Hardwicke, 1872. MR. THE MARTYRDOM OF MAN.* [R. WINWOODE READE, in his early work on Africa, while his style was repulsive to many readers, nevertheless gave a good account of his travels. In the present work he has given us over five hundred pages of matter, which is simply a very shallow rendering, in one volume, of the more immoral portions of the popular histories of some four or five nations. The book, while intentionally it has an aim, has really none whatever. It is marvellously constructed, no succeeding chapter having any relation to its predecessor, nor anything in the form of a vein of continuity running through the book. Towards the end we are treated to the author's views upon religion, and in this portion, while we agree with him in some of his views, we must say that he has not the slightest novelty to introduce, and that he argues in favour of his views with a poverty of logic that is somewhat astonishing in one who writes upon such a subject at all. There is but one good thing in the book, and that is the style in which it is written. Evidently the author has been at pains in the mode of expressing his ideas, and has doubtless paused considerably and erased much ere he gave his copy to the printer. So that on the whole a feeling of unpleasantness steals over the writer as he imagines the pain and difficulty of composition. Still we must admit that it is very good, the mode of expression being throughout terse, clear, and sometimes even epigrammatic. But when we have said this we have given every particle of praise which can be bestowed on a book that is really without aim or object of any kind save the gratification of the foolish ambition of having written. It seems to us as though Mr. Reade wanted experience, as though he had but a capacity of seeing himself and his own views alone, and thus he was led to write for others that which they themselves understand infinitely more fully and better than he does. While we agree with him in the doctrines he holds, so far as we can see, we are somewhat astonished at the logical accuracy of some of his stated conclusions. "In the first place," says he, "we shall state as an incontrovertible maxim in morality that a God has no right to create men except for their own good." Now we should very much like to know on what principle or by what data in the laws of morality Mr. Reade arrives at this conclusion. Most assuredly we fail entirely to see it, as indeed we fail throughout his whole argument to perceive any but the most shallow reasoning, put forward in terse style, and an intense amount of egotism unalloyed by anything in the shape of respect for the opinions of others. Nevertheless it is an amusing, well-written book, which those who agree with the author will be interested by reading. There is a freshness in its want of generalisation, and an amusing absence of consideration for others which we doubt not will prove refreshing to the mind of an average reader. The Martyrdom of Man. By Winwoode Reade. London: Trübner and Co., 1872. RICHARD TREVITHICK.* ASSUREDLY it must have been a labour of love on the part of the son who has given us these two large volumes on the life of Richard Trevithick. If he expects to make money out of them, he must be vain indeed. Still we must hope that to those interested in the progress of mining, engines, and machinery they will have a certain value and importance. Truly the man whose life is here given must have been devoted to the pursuit he was engaged in, for he seems to have been during his whole life attached to the invention of machines for rendering mining more simple and expeditious; and numerous indeed appear to have been his inventions. We do not perceive that he possessed any of that great inventive power so common to Watt and Stephenson. Nor do we find in his life any of those occasions in which, as it were, a man is led back from his special calling to the more general concerns of mankind. This may be, however, from the fact that the present writer had not the materials at his command. Therefore the volumes, while they must have a particular interest for the engineer, are devoid of those incidents which render a book of the kind attractive to the reader of biography. It seems to us that the author had hardly the capacity for a biographer, and that he would have done better had he placed the task in other hands. Still, the book is not without interest to the practical engineer. SHORT NOTICES. Edited by S. F. Baird. attempt in America to Annual Record of Science and Industry for 1871. New York: Harper Brothers, 1872. This is the first publish a yearly record of the progress in different branches of science. It includes every branch, and does not, so far as we have seen, give to any one department greater space than another. It seems to be very fairly done; but we must assure the editor, that unless he covers at least three times the space at present occupied, he cannot expect to produce anything like a tolerably faithful record. We would urge on him also the propriety of considerably shortening some of the paragraphs, and of totally excluding others. It seems a good work, and we hope to see the succeeding volumes, on the plan we suggest. Magnetism and the Direction of the Compass. By John Merrifield, LL.D., F.R.A.S. London: Longmans, 1872. This is a little manual for the use of students in navigation and science schools, and it appears to be very well prepared. It deals both practically and scientifically with the several questions arising out of the deviation of the compass, and is clearly a practical and useful volume. (Other notices are pressed out through want of space in this, the index No. of " Popular Science Review.") * Life of Richard Trevithick, with an Account of his Inventions. By Francis Trevithick, C.E. Wood engravings by W. J. Welch. 2 vols. London: E. & F. Spon, 1872. 414 SCIENTIFIC SUMMARY. DR. ASTRONOMY. R. DE LA RUE'S address, to Section A. of the British Association, was one of the features of the recent meeting. We quote from it the following passages :— The Solar Corona.-" The great problem of the solar origin of that portion of the corona which extends more than a million of miles beyond the body of the sun has been by the photographic observations of Colonel Tennant and Lord Lindsay in 1871 set finally at rest," says Dr. De la Rue, “after having been the subject of a great amount of discussion for some years. The spectroscopic discovery in 1869 of the now famous green line, 1474 K, demonstrated undoubtedly the self-luminosity, and hence the solar origin of part of the corona. Those who denied the possibility of any extensive atmosphere above the chromosphere received the observation with great suspicion; but in 1870 and again in 1871 it was fully verified. So far, therefore, the testimony of spectroscopic observations was in favour of the solar origin of the inner corona. Indeed the observations of 1871 have proved hydrogen to be also an essential constituent of the coronal atmosphere,' as Janssen proposes to call it-hydrogen at a lower temperature and density, of course, than in the chromosphere. Janssen was further so fortunate as to catch glimpses of some of the dark lines of the solar spectrum in the coronal light, an observation which goes far to show that in the upper atmosphere of the sun there are also solid or liquid particles, like smoke or cloud, which reflect the sunlight from below. Many problems, however, even with reference to the admittedly solar part of the corona, are unsettled. The first relates to the nature of the substance which produces the line 1474 K. Since it coincides with a line in the spectrum of iron, it is by many considered due to that metal; but then we must suppose either that iron vapour is less dense than hydrogen gas, or that it is subject to some peculiar solar repulsion which maintains it at its elevation, or other hypotheses may be suggested for explaining the fact. Since the line is one of the least conspicuous in the spectrum of iron and the shortest, and as none of the others are found associated with it in the coronal spectrum, it seems natural, as many have done, to assume at once that it is due to some * Dr. De la Rue on "Recent Astronomical Progress." |