376 



SCIENTIFIC NE^A^S. 



[April 20, iS 



but they may be round (common sorrel) or square, or 

 contained in little specially-formed hairy cavities as in 

 the oleander. One of the most remarkable forms of 

 stomates is found in some of the liverworts, vjhere the 

 guard-cells are four or more tiers high, each tier being 

 divided into four or more segments, forming a little 

 chimney-shaped eminence which leads into a rhomboidal 

 chamber between the epidermis and the subjacent tissue. 

 Some of these latter may be seen with a lens. The 

 stomates when expanded vary in size from about the 

 four-thousandth part of an inch in the white lily, in which 

 case the whole stomal apparatus becomes visible with a 

 lens, to 1-500, 000th of an inch in Agapanthus umbellatus. 

 The advantage arising from such minuteness lies chiefly 

 in the prevention of the entrance of water, dust, and 

 fungus-spores. Yet this extremely sUght communication- 

 with the air does not prevent the egress and ingress of 

 vapours and gases, whilst, as has been shown, their 

 number is of such magnitude as to make such communi- 

 cation of immense practical value to the plant. It is by 

 the use of such properties as these — properties which are 

 too subtle in their action to allow of ordinary observation 

 — that Nature does the greater part of her most wonderful 

 work, not only in the plant-world, but through all her 

 domain. 



- — •-^♦^'^'tf-' — ' 



The Fundamental Principles of Chemistry. By Robert 

 Galloway, M.R.I. A., F.C.S. London : Longmans. 

 1888. 



Should any of our readers wish to learn what chemistry 

 is as a science, not as an assemblage of facts classified, if 

 classified at all, on a plan resembling that of certain book- 

 owners who think afflnity in bindings the only affinity 

 worth considering, we recommend them to buy Pro- 

 fessor Galloway's admirable little work. No reading 

 of text-books, great or small, will give them so firm a 

 grasp of the subject as will his method. It is true 

 that his method is not for those who must run while 

 they read, lest they arrive too late at the examination 

 goal, but for the earnest student, for the man who 

 values intellectual honesty and sincerity more highly 

 than outward show. Yet none the less do we, even 

 in this day, when there is so much intellectual show and 

 so little sincerity, urge our readers to take this book in 

 their hands and prepare themselves by its aid to derive 

 real profit from further study in text-book and labora- 

 tory. 



No one who has not had experience as a teacher of 

 chemistry knows how nearly hopeless it is, under exist- 

 ing regulations and customs, to get into the head of the 

 average student, especially the average medical student, 

 for whom chemistry is a casual incident to be escaped 

 from as rapidly as possible, any understanding of 

 principles, any knowledge of facts sufficiently coherent 

 to stand the test of time. Professor Galloway's book 

 should go far towards helping teachers and students to 

 find a way out of their difficulty, and we wish it the 

 great success it deserves. 



The plan adopted necessitates the giving up of a large 

 part of the book to an exposition of the physical pro- 

 perties of matter ; but this is really one of its chief re- 

 commendations, for the student is often tempted to 

 neglect physics as being dull and difficult, and to lose 

 sight of the fact that he cannot attain a knowledge of 



chemistry without it. Professor Galloway, by explana- 

 tion, illustration, and experiment, will bring home to him 

 the laws of heat, and of molecular, and atomic 

 attraction, and the physical properties of gases, liquids, 

 and solids ; and then will take him on to chemistry as 

 generally understood, whereby he may learn to think 

 intelligently, and not mechanically and stupidly, ot 

 elements and compounds, of acids, bases, and salts. 



The examination questions given in each chapter are 

 models of what examination questions should be, for 

 they oblige the pupil to reason from data previously 

 acquired, and do not merely demand on his part a 

 repetition of those data. For instance. Question 348 is, 

 " Explain why coal-gas burns quietly when it issues 

 from a gas-burner, whilst a mixture of air and coal-gas 

 explodes on being lighted ? " and another asks the pupil 

 why " a cold plate held above the flame of a candle is 

 bedewed with moisture, and if held in the flame is 

 covered with soot." We wonder, sadly, how many 

 students taught on the usual system could give good 

 answers to these two questions, but we fully believe that 

 those who follow the new system will find them devoid 

 of difficulty. 



In view of a second edition of this excellent book, we 

 call attention to the occurrence of a few misprints, 

 notably to the turning upside down of the column of 

 atomic volumes on page 244, which results in making 

 the molecule of hydrogen tetratomic, and that of bromine 

 monatomic. 



Proceedings of the Royal Physical Society. Edinburgh. 

 Session CXVI. 



We may be permitted to wonder why a body which 

 appears to concern itself principally, if not exclusively 

 with biology, should call itself a "Physical Society." 



The address of the President, Mr. J. A. Harvie -Brown, 

 is devoted to the " Isle of May, its Faunal Position and 

 its Bird-Life." This island lies at the mouth of the 

 Frith of Forth, and though only a mile in length, by a 

 quarter of a mile in breadth, it is, like Heligoland off' the 

 Mouth of the Elbe, a most important station for observ-_ 

 ing the great bi-annual migration of birds. Mr. Harvie- 

 Brown points out its importance as a halting-place in the 

 track of the migrants. He briefly summarises some 

 of the facts collected within the last few years by 

 the Migration Committee of the British Association. He 

 then describes the physical geography of the Isle 01 

 May; and he treats of the actual bird-life of the island, 

 collating all that had been previously known, and con- 

 densing the records of the passing migrants. 



Among the principles ascertained is that the line of 

 the autumn migration of land birds across the North 

 Sea is invariably from easterly directions to westerly 

 ones, or from directions south of east to north 

 of west. Birds prefer to travel with a wind from 

 two to four points against their line of flight, because 

 this wind smoothes down their plumage, keeps it 

 close to the body and enables them to use their tails as 

 rudders. They do not willingly migrate with a follow- 

 ing wind. Should NW. or W. or even SW. winds pre- 

 vail upon our eastern coasts, normal migration ensues. 

 With a beam wind birds fly low and steady. With a 

 wind astern they are borne higher, lose their steering 

 power, and are often lost. They have been observed at 

 the height of four miles. In hazy weather they rapidly 

 descend, so as to find their obliterated land-marks, and 

 are often lured to destruction by the glare of lighthouses. 



