first year's course is only preparatory, and chiefly chemical. The student first learns the properties of the elements, and thus becomes, to some extent, acquainted with the characters of such species as the diamond, graphite, sulphur, and the native metals. He then advances to the study of simple chemical combinations, and is thus made acquainted with the chief acids and metallic oxides. This chemical course occupies a summer session, and is followed, during the succeeding winter course, by the study of the physical properties of minerals, as demonstrated on certain species of simple composition. Our author's mode of teaching may be illustrated by an example of his lesson on Quartz. A piece of common quartz is exhibited to the class, pulverized, and treated successively with water and the ordinary acids, for the purpose of showing its insolubility in these reagents. A small quantity is then mixed with an alkaline carbonate, and slowly heated for a quarter of an hour in an iron capsule. The effervescence consequent on the expulsion of the carbonic gas points to the acid character of silica; while the formation of a vitreous silicate illustrates the chemical composition of glass. During these experiments, an apt teacher will, of course, entertain his class by a valuable lesson on the manufacture of glass, and by explaining the method pursued in the analysis of siliceous minerals. Having thus become familiar with the chemical characters of the species, a well-formed piece of rock-crystal is exhibited to illustrate its crystalline form. The sixsided prism and its two terminal pyramids furnish a text for much instruction on the crystallography of the hexagonal system, whilst models of the forms are made in clay before the class, or, still better, by the students themselves. Attention is then directed to the other physical properties of quartz: its hardness is shown by its resistance to the knife, and by striking sparks with steel; its specific gravity is taken; its phosphorescence exhibited; and electricity is developed by friction. In this way the student becomes interested in chemical and physical science; and if no other scientific study be introduced into a system of general education, much solid instruction can be imparted by a judicious study of our common minerals.

The second year's course comprehends work of a more strictly scientific character, and includes the principles of classification and a description of the more important mineralogical species.

To supply a work adapted for instruction of this practical kind, Dr. Senft has prepared a useful Text-book of Mineralogy and Lithology. The first part is devoted to the general principles of mineralogy; the second, to a description of the principal species; and the third, to the study of rocks or aggregates of minerals. In the notice of species those only are described which have acquired importance by their wide distribution, by their applications in the

arts, or by their functions as rock-constituents. A few rare species are, indeed, described, but only on account of certain marked peculiarities, either physical or chemical. Two plates of crystalline forms bring the work to a conclusion.

Vegetable Teratology: an Account of the Principal Deviations from the usual Construction of Plants. By MAXWELL T. MASTERS, M.D., F.L.S. London: Published for the Ray Society, 1869.

THE attention which Dr. Masters has for many years bestowed on abnormal developments of the various organs of plants, renders this last publication of the Ray Society from his pen a peculiarly valuable one. The importance of a study of teratology, both to the morphological and to the systematic botanist, in determining not only the true relationship of organs to one another, but the structural position of difficult orders, has only recently been acknowledged. Moquin-Tandon's has been heretofore the standard work on the subject, but is completely out of date in the light of modern research; since his time St. Hilaire, Morren, and others have investigated the subject; but up to the present time nothing of importance has appeared in this country, except a very old treatise by Hopkirk.

The classification of a number of facts necessarily so unconnected with one another as monstrosities and irregular growths presents considerable difficulties; in our present imperfect state of knowledge of the causes of these variations from typical structure, we think Dr. Masters has done wisely in adopting in the main MoquinTandon's somewhat empirical arrangement, rather than attempting one with more claims to a philosophical basis. He arranges the phenomena under four heads:-1st. Deviations from ordinary arrangement, including union or independence of organs and alterations of position; 2nd. Deviations from ordinary form; 3rd. Deviations from ordinary number, whether increased or diminished; and 4th. Deviations from ordinary size and consistence, including hypertrophy and atrophy. Under any classification a certain amount of repetition is unavoidable; but is probably as small under the one here adopted as could reasonably be expected.

The work does not profess to be a philosophical treatise on the causes of aberration from typical form, but rather a chronicle of the most important instances which have come under the notice of the writer himself and of other observers; and the immense variety of these deviations from the usual construction of plants must astonish the casual observer. We have well-authenticated examples, for instance, not only of the comparatively common transformation of

sepals into petals, or of complete suppression of the calyx or corolla, but of the far rarer production of ovules within the anthers, in the case of a Cucurbita, and of pollen within the ovules in the instance of a passion-flower. Scarcely less curious is the formation of a flower-bud within the pod in the charlock, and of a miniature siliqua in the place of a seed in the wall-flower. Of greater practical importance than these strange abortions, are the minor irregularities in the less vital organs, constituting the possible origin of new races that have obtained predominance in the "struggle for existence." To the physiologist who devotes himself to the investigation of the causes which lead to the production of abnormal forms, and of their connection with the origin of species, Dr. Masters's volume will be an invaluable repertory of facts. We cannot too highly commend the care with which the innumerable instances that must have come before him have been sifted, and those selected which are undoubtedly authentic, and which may be considered as typical; or the labour which has been bestowed on the bibliography of the subject, consisting mainly of separate articles and descriptions in the various English and foreign botanical magazines, collated under the different heads into which the book is divided. The volume is illustrated with upwards of 200 capital drawings by E. M. Williams; many of the best of which have already appeared in the pages of the Gardener's Chronicle' and other publications. We are glad to hear that a translation of the work into French is already arranged.

Cyclopedic Science Simplified. By J. H. PEPPER. London: F. Warne and Co., 1869.

PROFESSOR PEPPER has not only distinguished himself by the eminently practical way in which he has converted the Polytechnic Institution from a losing to a paying speculation, by discovering the proper combination of electricity, conjuring, dissolving views, chemistry, ghosts, and comic songs-a sort of scientific Punch, in fact-which draws the largest audiences; but he has brought the same talents to bear upon literature, and has given to the world, at intervals, three books-The Play Book of Science,' 'The Play Book of Metals,' and the one now under our notice. Looking at these books from a highly scientific stand-point, we have no doubt much fault might be found with each of them; but from the point of view of that large section of the public whom Professor Pepper addresses, it would be difficult to say how they could be greatly improved. The present book embraces Light, Heat, Electricity, Magnetism, Pneumatics, Acoustics, and Chemistry. In each of these subjects, a large amount of information, generally of the

newest character, is given; the original papers on the various subjects as read before the learned societies being copiously quoted. As the author is almost bound, he gives full details of the various illusions and scientific tricks, ghostly and tangible, which have tended so much to popularize the Institution with which he is connected. The illustrations are numerous, and valuable in many cases, possessing an interest to men of the highest attainments in their respective spheres; and the initial engravings to the chapters are in many cases portraits of eminent philosophers. Thus, on page 197 we have James Watt, with autograph; at 392 is one of the best portraits we have ever seen of Sir Charles Wheatstone; on page 527 is an excellent portrait of Faraday; and at page 578 is one of Sir David Brewster. In addition to these, there are over 530 woodcuts, some of most elaborate description, and a chromolithograph as frontispiece, in which the author is exhibiting to an astonished audience the wonders of spectrum analysis, on a scale of magnitude never before witnessed.

Taking all things into consideration, we have no hesitation in saying that 'Cyclopædic Science' is one of the best books for boys we have ever met with. Its intrinsic attractiveness will do much to give a taste for science, and lead to a spirit of inquiry which will not be satisfied until the young philosopher possesses an experimental laboratory of his own.

CHRONICLES OF SCIENCE,

Including the Proceedings of Learned Societies at Home and Abroad; and Notices of Recent Scientific Literature.

1. AGRICULTURE.

THE past three months have bristled all over with topics of agricultural interest-many of them, unfortunately, involving disagreeable experience. It is certain, now that a large portion of the wheat crop has been threshed, that the harvest of 1869 has been very much below the average productiveness of past years: and the low prices which wheat commands, owing probably to no one wanting corn in the general market of the world except ourselves, whatever their benefit to the nation at large, have materially aggravated to English farmers the injury of a deficient yield. -The foot and mouth disease-a cattle plague of more or less virulence and frequency ever since 1839, when it first appeared-has been unusually general and severe during the past autumn. It is now, however, believed to be on the decline. Though rarely fatal, it is a painful malady, stopping the milk of cows and wasting the flesh of fatting cattle, and thus destroying the property of stock owners. It is generally supposed to be an importation from the Continent; but though that probably was true thirty years ago, it can now hardly be doubted that the disease has become indigenous. Careful quarantine, both at the ports of debarkation, and in home localities wherever it exists, has, however, all along been urgently demanded, and it has been at length conceded, so that we may hope to see the evil reduced within less serious limits.-The miseries of cattle transit, whether by land or by sea, have been urged on public attention, especially by the interest which Miss Burdett Coutts has taken in the subject. The use of a railway cattle-truck, in which live stock shall have access to both food and water on a long journey, is most desirable; and it is believed that the inferior condition in which cattle after a railway journey reach the metropolitan market from great distances, when they have had no refreshment on the road, must at length make consigners of such cattle willing to pay the expenses involved in the provision of better accommodation. An experiment directed by Miss Coutts, in which six cattle were sent from Edinburgh to London, shows that cattle will eat and drink upon the way with great comfort to themselves and great advantage to their owners, if they have the opportunity. The condition of Ireland, which is to a great extent an agricultural question, has of late occupied the public mind more painfully than any other