April ii, 1901] 



NA TURE 



561 



mere symbols. The analytical working out of problems 

 is given with unusual fulness. On the whole this is a 

 distinct advantage to the beginner, though in some cases 

 it has been a little overdone, as, for instance, on pages 

 190-193, where more than 2^ pages are devoted to the 

 analytical work of a triple integration. Each chapter 

 contains several examples fully worked out, and con- 

 cludes with a number of exercises to which the answers 

 are appended. 



The arrangement of the book is good, but the section 

 dealing with real and imaginary quantities early in the 

 book, and that on the hyperbolic functions towards the 

 end, might have been omitted without much real loss to 

 the beginner, and certainly the former section is intro- 

 duced too early. 



A mistake occurs on page loi in reference to an 

 application to alternating electrical currents. The arith- 

 metical average has been confused with the square root 

 of mean square, with the result that the statement made 

 is incorrect. 



Engineering Chemistry. A manual of Quantitative 

 Chemical Analysis for the use of Students, Chemists 

 and Engineers. Second Edition. By Thomas B. 

 Stillman. Pp. 503. (Easton, Pa. : The Chemical 

 Publishing Co., 1900.) 

 This work is intended to be placed in the hands of the 

 student who is commencing quantitative analysis, and 

 hence the first eleven exercises deal with general elemen- 

 tary determinations, after which he will take up that 

 portion of the book which deals with his special require- 

 ments. Schemes are then given for the analysis of coal 

 and coke, iron ores, water, both for sanitary and technical 

 purposes, of coal, oil, producer and flue gases, iron and 

 steel, cement, building materials, paper, soap, lubricating 

 oils, paint and asphalt.. On account of the wide scope 

 of the book, the author has secured special articles from 

 experts on blast furnace practice, boiler tests, carbon 

 compounds of iron, practical photometry, electrical units 

 and energy equivalents. As must necessarily be the case 

 from the size of the book and the variety of subjects dealt 

 with, the work is written in a very compressed style 

 throughout, so much so, in fact, that it is scarcely a suit- 

 able work to put in the hands of " students commencing 

 quantitative analysis." The large amount of practical 

 information in it, however, will render it a useful work of 

 reference for chemists engaged in engineering work. 

 In some respects there is room for improvement 

 The superabundance of decimal places in numerical 

 results, which is, unfortunately, characteristic of American 

 technical literature, is very much in evidence. Thus in 

 an analysis of water for technical purposes, the con- 

 stituents of which, on account of their minuteness, are 

 weighed with an accuracy of about two, or at the most 

 three, significant figures, in the final statement of results 

 no less than five places are given. An even more striking 

 case is in the section on calorimetry, in which the water 

 equivalent of a calorimeter is laboriously worked out to 

 six significant figures, 203"46o, the experimental result 

 being casually given as 227'22. Another example is in 

 the determination of the heating value of a gas, the result 

 being expressed as 107267 B.T.U. per pound. The 

 section on photometry is somewhat out of date, no 

 mention being made of any standard of light other 

 than the sperm candle. The chapter on pyrometry and 

 many of the numerical data also require bringing up to 

 date, many of the tables and calculations being based 

 upon the weight of a litre of hydrogen taken as o'oSgjS. 

 A noteworthy feature, and one adding considerably to 

 the value of the book, is the introduction of a short biblio- 

 graphy at the end of each special chapter. It is curious 

 to note that in some cases recent papers of importance 

 are given as references, but ignored in the text. This is 

 especially noticeable in the chapter on pyrometry. 



NO. 1 64 1, VOL. 63] 



LETTERS TO THE EDITOR. 



{The Editor does not hold himself 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 of Nature. 

 No notice is taken of anonymous communications.\ 



Darwinism and Statecraft. 



Every one who is interested in the bearing which the teaching 

 of biology has to the affairs of the nation must have followed 

 with interest not only this last work of Prof. Pearson, but 

 also his many contributions to the subject of heredity. Very op- 

 portune, also, is Prof. Lankester's appeal in his review (March 21) 

 to " the greatest in the land," for apart from the fact " that the 

 crowd cannot guide itself in its blind impotence," it is being 

 otherwise led by the hysterical nonsense of a halfpenny Press 

 that is degrading journalism and the people by the substitution 

 of bombastic ignorance and assertiveness for knowledge and real 

 merit! 



It seems to me that the statement in Prof. Pearson's book of 

 what the British parent ought to say is just what he should not 

 say, and that the implication in Prof. Perry's review that the 

 development of the faculties ought to begin at the public schools 

 is open to objection because such beginning can and ought to be 

 made very much earlier. The statement which Prof. Pearson 

 would have the parent say would be better if it were altered so 

 that for " son " we should read " children," for surely we require 

 thinking and observing daughters as well as sons ; and, more- 

 over, the statement seems to imply that the parent expects the 

 public school or the University to teach his son to think and 

 observe, whereas, if the parent did his duty, the most that he 

 ought to expect of these institutions would be the further develop- 

 ment of his children's thinking and observing powers, and not 

 their initiation in these matters. 



We need thinking men, it is true ; but what is the nature and 

 source of the early influences that makes or mars their careers 

 before they will be brought into contact with the educational 

 system that is to make them thinkers ? Are we not on the 

 wrong track when we talk of " making thinkers " or of " train- 

 ing men to think " ? Remembering the nature of the child, 

 rather it seems to me that we should be nearer a successful issue 

 if we turned our energies in the direction of retaining and develop- 

 ing the thinking powers it naturally possesses. Any one who 

 chooses to observe the development of a child's mind will, if he 

 does not suppress its natural bent, convince himselt that a child 

 from three to five years of age possesses thinking powers of 

 greater capacity than we are in the habit of crediting to it. One 

 of the external evidences of a thoughtful mind is the asking of 

 questions which bear definite and logical relations to each other ; 

 and this is precisely what an average child of that age, when 

 talking to a person in sympathy with it, is persistently doing. It 

 is not content with a flimsy and evasive answer, and how strong 

 is its intellectual craving is manifested by its evident disappoint- 

 ment or display of temper when its ignorant parents impatiently 

 curb its curiosity. It is very seldom that one finds a mother 

 who has endeavoured to retain her child's thinking capacities. I 

 was once present when the four-year-old little daughter of such 

 a mother was making inquiries about the planet Venus, and 

 after she had been informed that both Venus and the earth 

 travelled round the sun and were illuminated by it she put the 

 query, " Then if there were people on Venus our earth would 

 look to them like Venus looks to us ? " This question demon- 

 strates that a child possesses thinking powers sufficiently vigorous 

 to enable it to see the logical relationships of bodies to each 

 other that would certainly do credit to many of its superiors in 

 point of years. This is not an isolated instance, and my im- 

 pression, derived from observation and from conversation with 

 observant persons, is that the average child, if not sup- 

 pressed, is capable of a quality of thinking that leads its elders, 

 when they try to follow it, into an intellectual quagmire of 

 inconsistency and absurdity from which they beat an inglorious 

 retreat by angrily bidding it "not to ask silly questions." If they 

 bid themselves not to give silly answers their request would be 

 just. Let me give an instance of the intellectual stagnation 

 upon which the children who will become the nation's men are 

 being reared. I once heard a child ask its mother, " What 

 makes the flowers grow ? " Promptly came the answer, "Jesus ! " 

 No wonder when children's intellects are muddled with such 

 unprovable assertions that they cease to think. I recall my 



