407

REVIEWS.

HENFREY'S BOTANY.*

IT is a strange fact, but not the less is it a true one, that while all other

branches of science have made immense advances in this and in other countries, Botany has, in England at least, remained pretty nearly as it was ten years ago. Of course we mean to refer to structural and scientific botany, and not to the mere collection and increasing of plants which sometimes we think improperly receives its name; for it indeed is one thing to gather and dry and name a quantity of plants and fruit, and another to discover the general laws by which they obtain their nourishment from the soil, or bring forth the seed in due time, or are distributed over different parts of the globe. We do not for a moment wish it to be inferred that we desire to direct attention to these phenomena above all others. What we do mean and what we will say is this, that it is especially to them that the attention of students should be directed, if any good is to come from regular botanical study. And believing this, it has always been a matter of regret to us that Professor Henfrey was removed from amongst us; for we doubt not that, had he remained, much would now have been done which has been left undone in the department to which we have alluded.

But while we hold this opinion, which it would be unfair not to admit, we must not place ourselves in such a position that we shall not be able to recognise the labours of others in the same field. We must, while we sufficiently regret the dead, not leave ourselves unable to recognise the good and laudable work of the living; and it is for this reason that we should direct attention to recent labourers in the same field, and especially to the active labours of Dr. Masters, now before us.

Before the time of Henfrey, it may well be said that there was no teacher of elementary botany in England. There was, of course, Balfour's work, and Schleiden's admirable treatise, translated by Dr. Lankester; but while the first was a simple, practical summary of the state of knowledge, the latter was a different work, containing very fully the author's able views of some questions like that of fecundation, but very deficient in other par

"An Elementary Course of Botany, Structural, Physiological, and Systematic." By Professor Arthur Henfrey, F.R.S. Second edition, revised and in part rewritten by Maxwell T. Masters, M.D., F.R.S. London: Van Voorst, 1870.

ticulars. Then about thirteen years ago came the valuable work, now in its second edition, and from its date came a revolution in English teaching. Perhaps of the few who are working at botany generally, no one was more thoroughly qualified to take up the work and bring it down to the present period than Dr. Masters. And as the work of the preparation of new editions goes on, we must congratulate him upon the clear good sense which influenced him in leaving the great bulk of the volume as it was before. Indeed, with the exception of the portion devoted to the description of the natural orders, we do not observe much change in the work; and for this we beg to offer our best thanks to the learned editor, for he has seen how very far in advance of the mere botanist the former author of the work was, and has recognised it accordingly. It is especially, as far as we can see, in regard to the description of the natural orders, that the author of the new edition has had the part to play, and so far he has done his work well and modestly. Dr. Masters' work has been both laborious and well executed. While he has admitted a great many orders, which, if our memory serves us, were not there before, he has been cautious in doing so, and has not admitted more than the mere necessity of the occasion demanded. Furthermore, he has been terse in all cases,-no mean quality in an editor.

The great bulk of the work is as it was before. In certain cases many additions have been made, in others hardly any. But in all respects we must regard Professor Henfrey's treatise as being the very best text-book on botanical science which our language possesses.

HUMAN HISTOLOGY.*

WITHIN the past five or six years how very little good work has been

done in this country in Histology! It is strange that with the best kinds of microscopes, and the cheapest in the world, we have done so little in histology. We cannot understand why so much good work comes from abroad, where microscopes are dearer and worse, as a rule, than ours, unless it be that education is so far ahead of us. But yet why should that prevent large bodies, like the Royal Microscopical Society and the Quekett Club, from undertaking the labour? We cannot tell. But there is no denying the fact that for the one worker at human histology in England there are, on a moderate estimate, from three to five abroad. Even taking the men who have contributed to the present volume alone, we find over thirty who, so far as we can remember, are from that part of the world which rejoices in the name of a fatherland. And where is what we are to show from England?

But if we leave aside for the present the question of comparison, and inquire on what this volume proposes to treat, we find that its subject

"Manual of Human and Comparative Histology." Edited by S. Stricker. Vol. I. Translated by Henry Power, M.B., F.R.C.S., Examiner in Physiology in the University of London. The New Sydenham Society. London: 1870.

That is to say,

matter is general, but, so far as possible, confined to man. that the different writers treat upon the subject of human histology, and bring in comparative facts whenever there seems a necessity for them. To the medical man especially, the several chapters will be of especial interest, since they bring up the knowledge of the subject to the latest (or nearly so) date. But the first chapter is one which every microscopist would do well to read. It deals with the subject of microscopy, and recounting objects and the different applications of electricity, gas, &c., which have been made of late years by men like Recklinghausen, Stricker, Deville, Kühne, Schultze, and Brücke. It forms a kind of introduction, a preparatory chapter to the work, and is, we believe, from the pen of Herr Stricker himself. The remainder of the work, extending over exactly six hundred pages, deals with cells, connective tissues, nervous tissue, organic muscles, relation between ultimate fibres of nerve, muscles, muscle under the polariscope, the heart, blood-vessels, lymphatics, spleen, thyrus, thyroid, blood, salivary glands, teeth, the whole alimentary and intestinal canal, and, lastly, of the blood-vessels connected with the alimentary canal. In each case the most recent views are given, and the volume is full of interest to those to whom it has any interest. We cannot speak too well of Mr. Power's efforts as a translator. He has had a difficult task to perform, and he has done it admirably well.

WE

ON HEAT.*

E see, with not a little satisfaction, that this work has actually gone through four separate editions since the year 1863, and so far we have every reason to be satisfied. It must be confessed that it is the only work which the English student finds convenient. But this is not all; it is carefully brought up in each edition to the state of actual knowledge of the time, and even the present edition contains matters and facts not to be found in any of the earlier issues.

It will be well, therefore, if we pay attention to some of the more striking of the novelties which the present volume possesses over its predecessors. Firstly, we have in this the relations of gaseous matter to the shorter waves of the spectrum. Then comes the consideration of the blue of the sky and the polarisation of its light; and, lastly, we have the hypothesis regarding the constitution of comets, or the polarisation of heat. Perhaps of all these the sky-question is at once the most generally interesting and practicable of all. We shall endeavour to follow the professor's description, though it is a little difficult, because of the space at our disposal to do so. Having described fully a small tube filled partly with nitrate of amyl, and peculiarly connected, he goes on as follows: "Opening the cock cautiously, the air of the room passes in the first place through

"Heat a Mode of Motion." By John Tyndall, LL.D., F.R.S., Professor of Natural Philosophy in the Royal Institution of Great Britain. Fourth edition. London: Longmans, 1870.

the cotton-wool which holds back the numberless organic germs and dustparticles floating in the atmosphere. The air thus cleansed passes into U-shaped vessel, where it is dried by the sulphuric acid. It then descends through the narrow tube to the bottom of the little flask, and escapes there through a small orifice into the liquid. Through this it bubbles, loading itself to some extent with nitrite of amyl vapour, and then the air and vapour enter the experimental tube together. We will now permit the electric beam to play upon this invisible vapour. The lens of the lamp is so situated as to render the beam convergent, the focus being formed about the middle of the tube. You will notice that the space remains dark for a moment after the turning on of the beam; but the chemical action will be so rapid that attention is requisite to mark this interval of darkness. I ignite the lamp; the tube for a moment seems empty; but a luminous white cloud immediately fills the beam. It has in fact shaken asunder the molecules of the nitrite of amyl, and brought down upon itself a shower of particles, which cause it to flash forth in your presence like a solid luminous spear. This experiment, moreover, illustrates the fact that however intense a beam of light may be, it remains invisible unless it has something to shine upon. Space, though traversed by the rays from all suns and all stars, is itself unseen. Not even the ether, which fills space, and whose motions are the light of the universe, is itself visible."

We take the foregoing, as one of the most striking of the novelties in this admirable work, and also one of the most interesting of the recent facts recorded by the author. But the whole work is full of such, and we cannot do better than recommend those of our readers who are already unfamiliar with it, to procure it for themselves at once. It is not only the best work on the subject in the English language, but it is in itself especially valuable as an eloquent and comprehensive treatise.

THE

BUILDING.*

HE author tells us of this work, that he has endeavoured to introduce the student of architecture to a general outline of scientific subjects connected with his profession, an acquaintance with which at present involves the reading of a large amount of works by various authorities. By so doing, he hopes to command the attention of the great mass of architects, for the mathematical knowledge required to understand what he has got to disclose, does not extend beyond elementary geometry and algebra. The book is divided into seven chapters, dealing with the following subjects: mechanical principles, retaining walls, arches and cupolas; building stones, timber, iron, and lastly water contained in vessels and pipes. So far as we have examined, the book seems clear and intelligibly arranged; but we must differ from the author, when he says, as he does say, that it is the only work of its kind. Unfortunately, too many books of all kinds are pub

"The Science of Building. An Elementary Treatise on the Principles of Construction, especially adapted to the requirements of Architectural Students." By E. Wyndham Tarn, M.A., Lond. London: Lockwood, 1870.