November 2, 1893] 



jVA TURE 



OUR BOOK SHELF. 



Inorganic Chemistry for Beginners. By Sir Henry 

 Roscoe, F.R.S., assisted by Joseph Lunt. (London : 

 Macmillan and Co., 1893.) 

 Everyone recognises the necessity for having works upon 

 elementary science written by men in thorough touch 

 with their subject. It is with some satisfaction, therefore, 

 that we notice this book, in which Sir Henry Roscoe 

 clearly expounds the elementary principles of chemistry, 

 and describes some of the non-metallic elements and 

 their more important compounds. The book differs froni 

 the author's well-known " Lessons in Chemistry " in 

 arrangement and in style, and is far better suited to the 

 tyro in chemistry. In fact, it is adapted to suit the re- 

 quirements of the syllabus of the Department of Science 

 and Art, and both teachers and students under the 

 Department will benefit by its introduction. There are 

 twenty-one lessons in the book, each complete in itself. 

 At the end of each lesson is a brief summary and a set 

 of questions bearing upon the subjects treated. Believing 

 with all educationalists that principles only become 

 apparent when they are reflected by facts, the author 

 illustrates each step with an experiment. One hundred 

 and eight illustrations elucidate the text, and though 

 many of them are of the ordinary stock character (which 

 is, perhaps, unavoidable in a book of this kind) a fair 

 proportion art from new blocks. In every respect the 

 book is a good one, and contains the kind of knowledge 

 that should be imparted to all beginners of science. 



The Chemistry of Fire. By M. M. Pattison Muir. 

 (London : Methuen and Co., 1893.) 



The fact that this book belongs to a University Extension 

 .Series vouches for the popular character of the contents. 

 Extensionists should welcome Mr. Pattison INIuir's con- 

 tribution to their literature, for it represents the work of 

 a practical teacher, and combines accuracy with sim- 

 plicity. It is now generally conceded that the best way 

 to teach chemistry is to deal first with common occur- 

 rences and things, and finally to generalise. Let a student 

 once obtain a correct notion of the changes of composi- 

 tion that happen in the burning of a candle, and he can 

 comprehend all chemical changes. We therefore com- 

 mend the book before us to the notice of committees and 

 organisers of technical education, for it contains just the 

 kind of linowledge that should be imparted to all students 

 under their guidance. Like the majority of the volumes 

 in the series to which this one belongs, >the illustrations 

 are few and very sketchy. On this account it will be 

 difficult for the home-reader to get a clear conception of 

 many of the experiments. 



Solutions of the Exercises in Taylor's Euclid I. to IV. 

 By W. W. Taylor, M.A. (Cambridge : University 

 Press, 1893.) 



By the publication of these solutions, Mr. Taylor has 

 furthered very considerably the usefulness of the book 

 written by his brother. In the book he has worked 

 out very fully all the problems, and has arranged the 

 text in such a form as to be thoroughly intelligible to any 

 student. Where several problems were of a similar 

 character, it has been thought expedient to adopt a 

 different mode of solution, while in some cases duplicate 

 solutions have been given. Extension of theorems 

 have here and there been inserted, and a few additional 

 exercises will also be found to have been interpolated. 

 By the adoption of a simple notation, reference can be 

 directly made to the problems in the " Pitt Press Euclid.'' 

 Both teachers and taught will find that they have a 

 very useful companion to the above-mentioned book, 

 while the latter will be very much enlightened in the art 

 of solving many problems. 



NO, 125 ^, VOL. 49] 



LETTERS TO THE EDITOR. 



[The Editor does not hold himsef responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part oj Natukj:. 

 No notice is taken oj anonymous communications. ^^ 



The Recent Glaciation of Tasmania. 



In a paper read before the Royal Society of Tasmania in 

 June last, Mr. R. M.Johnston, F.L. S., gives a sketch of wbnt 

 is known of the glaciation of the island, or rail)er of the 

 western portion of it, for no indications of glaciers appear lo 

 have been discovered in the eastern half. This difierence is 

 supposed to be due to the fact that on the western side of the 

 island the rainfall is from 50 to 76 inches annually, wliile in the 

 central valley it is but little over 20 inches. Indications ot 

 placialion among the western mountains were noticed by Mr. 

 Charles Gould, Government geologist, about forty )ears ago, 

 and from information received from him through the late Chief 

 Secretary of Tasmania, the Hon. J. R. Scott, Mr. Johnston 

 took up the inquiry, and for many years has made exploi aliens 

 in the western plateaus and mountains. Mr. C. P. bprenr 

 was anothc;r explorer who published some account of the glacial 

 phenomena in 1886, while more recently Mr. T. B. Moore and 

 Mr. Dunn have recorded similar observations. Mr. A. Mont- 

 gomery, the present Government geologist, has also just pub- 

 Hshed a paper on the same subject. 



Mr. Johnston tells us that he has personally explored the 

 whole of the western mountains, from the Picton and Craycrolt 

 Rivers, southern branches of the Huon, in the extreme iouih, 

 along the mountain ranges forming the western border of the 

 central plateau, quite through to Emu Bay on the north coast ; 

 and that he has found the clearest evidences of glaciation 

 in almost every valley throughout this great extent of country. 

 From the Arthur Range in the south to Mount Bischoff in the 

 north, are numerous moraines, roches moutonnees, tarns and lakes 

 in great abundance, polished and striated rock-surfaces, and 

 numbers of true erratics. Near the sources of the Franklin 

 River, under Mount Hugel, and only six or seven miles west of 

 Lake St. Clair, are Lakes Dixon and Undine, of which Mr. 

 Johnston writes : — "The valley of Lake Dixon is /«;-tU'a'//c«a', 

 the ideal of a perfect glacier valley. No one, however ignorant 

 of glacial action, could in this neighbourhood gaze upon these 

 beautiful scooped, or rather abraded lakes or tarns, the snow- 

 white, polished, billowy, and cascade-like roches moutcnnces, 

 composed of quartzites, on the upper margin of Lake Dixon, 

 together with the tumbled moraines and large erratics on the 

 lower banks — -at a level of about 2000 feet — without being im- 

 pressed with the idea that its singularly characteristic features 

 must have been produced by the slow rasping flow of an 

 ancient river of ice." 



Further north, the Murchison, Macintosh and Huskisson 

 rivers, ail branches of the Pieman River, contain similar 

 glacial markings ; and Mr. Dunn has recently described others 

 of the same character about Lake Dora, nearer 10 the wet 

 coast. The latter observer lays special stress on the rounred 

 planed and scored rocks, on hard quartzite and conglomeiate 

 rocks rounded and polished, on numerous tarns in rock-basirs, 

 on moraines covering hundreds of acres, and on numerous huge 

 erratics and perched blocks. (See Annual Report of the Secretaiy 

 for Mines, Victoria, 1893, p. 21.) 



Mr. T. B. Moore states that he found the rocks polished and 

 striated within 25 feet of the top of Mount Tyndall, or 3S50 

 feet above the sea, a sufficient indication that the great central 

 plateau at an average elevation of nearly 4000 feet must have 

 been buried in ice or neve to a considerable depth, and have 

 formed the feeding ground for the glaciers, whose effects are so 

 visible in the adjacent western valleys. The Tasmanian geolo- 

 gists are united in the belief that the glaciers never reached the 

 coast or descended much below the 2000 feet level, and that the 

 ice did not extend to the central valley or the eastern side of tl e 

 island. They therefore speak of it as a glacier, not a glacial 

 period, the conditions being somewhat similar to those of the 

 Alps at the present time ; but, owing to the great difference in 

 the rainfall, there was a more marked contrast between the 

 western and eastern districts, while the lofty central plateau 

 afforded a much more extensive snow-field than Switzerland 

 now possesses. 



The facts here stated on the authority of Mr. Johnston, sup- 



