432 



NATURE 



[March 8, 1894 



crystalloids, as they are termed, filter easily when in 

 solution. Glue-like substances, or colloids, as they are 

 termed, filter with difficulty." Statements like these are 

 calculated to mislead a student as to the differences 

 between simple filtration and dialysis. 



On the whole the book gives a large amount of in- 

 formation in a very small compass, and this is, speaking 

 generally, accurate. One of the best features is the 

 wealth of illustration, selected from well-known text- 

 books, which it possesses. J. S. Edkins. 



OUR BOOK SHELF. 



Light : an Elementary Text-book^ Theoretical an d 

 Practical, for Colleges and Schools. By R. T. Glaze - 

 brook, M.A., F.R.S. (Cambridge: University Press, 

 1894.) 

 The best foundation upon which a student of science 

 can build is elementary physics, for the necessity of 

 accurate observation and correct reasoning is impressed 

 upon him from the very beginning. Mere book-work has 

 no value in training the mind in this direction : lectures 

 illustrated with experiments may lead to the desired end 

 if the teacher take care that the inferences to be drawn 

 from the experimentation are quite clear ; but best of all 

 methods, by far, is to let the student perform the experi- 

 ments himself, to mark the result, and then reason out 

 the explanation. The advantages to be derived from 

 such practical work are incalculable, yet the small num- 

 ber of physical laboratories in our schools and colleges 

 at the present time shows that its importance has not 

 been fully recognised. There are, however, signs of 

 improvement. Judging from the increasing number of 

 books dealing more or less with practical physics, interest 

 in that subject is developing. Mr. Glazebrook's two 

 volumes, that on " Heat," recently noticed in these 

 columns, and the one now before us, help to extend the 

 practical method of teaching. Believing with most 

 scientific educationalists that courses of practical instruc- 

 tion are necessary to the proper understanding of funda- 

 mental principles, Mr. Glazebrook gives, in the volume 

 under review, clear descriptions of experiments, the 

 explanations of the theory underlying the work, and the 

 deductions to be made from the results. The theoretical 

 portion of the book could very well form the subject of 

 short lectures preceding the laboratory work, in which 

 the principles expounded at such times could be experi- 

 mentally tested. The book abounds with diagrams of 

 the kind that appertain to treatises on light. To the 

 artistic mind these figures lack beauty, but they possess 

 the qualification of clearness ; and that is sufficient to 

 commend them to the student of optics. Teachers who 

 require a book on light, suitable for the class-room and 

 the laboratory, would do well to adopt Mr. Glazebrook's 

 work. 



Beni Hasan. Part ii. By P. E. Newberry. With appen- 

 dix, plans, and measurements of the Tombs, by G. 

 W. Eraser. (London: Kegan Paul, 1893.) 



Some two or three months ago we called the attention 

 of readers of Nature to the first part of Mr. Newberry's 

 work on the rock-hewn Xllth dynasty tombs at Beni 

 Hasan m Upper Egypt, and we have now the pleasure to 

 record the appearance of the second and concluding 

 portion of this valuable book. We have already described 

 the general scope of the publication, and the plan upon 

 which it has been carried out, and it therefore only 

 remains for us to state the contents of the part before 

 us. Employing the same method of arrangement, Mr. 

 Newberry describes tombs Nos. 15-39, and he gives lists 

 of all the members of the households of the Egyptian 



NO. 1271, VOL. 49] 



noblemen who were buried at Beni Hasan ; the general 

 remarks which he makes upon them are interesting and 

 to the point. Too much praise cannot be given to the 

 thirty-seven plates which illustrate the text, for they give 

 the reader an accurate idea of the general appearance of 

 the scenes painted upon the walls of the tombs. Mr. G. 

 W. Eraser's "Report" (pp. 71-85) is also a very useful 

 addition to the book, and the copies of Greek and Coptic 

 graffti on pp. 65-68 will be welcome for several reasons. 

 We are glad to see that the system of transliteration of 

 Egyptian texts has been much modified, especially as the 

 non-expert will now be able to gain some idea of its 

 meaning and use. It is a great pity, however, that the 

 system as represented in Dr. Birch's " Egyptian Texts" 

 was not wholly adopted. 



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 t»/ NATURE. 

 No notice is taken of anonymous co7nmunications.'\ 



Great Auk's Egg. 



In your last issue (p. 412), I observe a letter from Prof. 

 Newton, in which he gives his version of the history of the egg 

 of this extinct bird, which was recently sold by auction for 

 ;^3i5. There is no doubt that the egg was brought to this 

 country by Yarrell, who purchased it in France some time 

 before 1838, in which year it was figured by Hewitson in his 

 well-known work on birds' eggs. But the question is, where- 

 abouts in France did he find it? Prof. Newton, who well 

 remembers it in the collection of Yarrell, says : " He told me, 

 as he told others of his friends, that he bought it in Pai-is, in a 

 little curiosity shop of mean appearance," and that he paid twa 

 francs for it. He adds that the only "variant" of this story 

 deserving of consideration, is to the effect that the price was five 

 instead of two francs. If this were the only "variant," it would 

 not be worth further discussion. But there is a very different 

 story told of it in Mr. Symington Grieve's important work on 

 " The Great Auk, its history, archaeology, and remains," pub- 

 lished in 1885. At p. 105 of this volume, Mr. Grieve writes of 

 this very egg ■■ — 



" The following curious story, which is well-known to ornitho- 

 logists, is so remarkable that we repeat it, and give a copy of 

 Mr. R. Champley's original note, dated June I, i860 : Mr. Bond 

 [who became the purchaser of the egg in question upon Yarrell's 

 death] says to R. C. — Yarrell told him that, walking near a 

 village near Boulogne, he met a fishwoman having some 

 guillemot's eggs. He asked her if she had any more ; she said 

 she had at her house. He went, when he saw hanging over the 

 chimney-piece four wild swans' [eggs], with a great auk's [egg] 

 hanging in the centre. She asked two francs each for them. 

 He bought the auk's, and two swans'. She said her husband 

 brought it from the fisheries. The great auk's egg sold at 

 Stevens's sale to Mr. Gardner for ;i^2l, [and was] sold again 

 by him to Mr. Bond for ;^26. Copied by R. Champley at Mr. 

 Bond's, by whom the history was told." 



Here then we have an important "variant" of Prof. New- 

 ton's version ; and as it was taken down in writing in i860, 

 within four years of Yarrell's death, from the lips of the 

 the late Mr. Bond, who had it frjm Yarrell himself, it seems 

 to me that it ought not to be passed over in silence. At any 

 rate, it affords some justification to the writers referred to by 

 Prof. Newton (see the Titnes of February 23), who, comment- 

 ing upon the recent remarkable sale, have naturally repeated 

 the only history they could find of this egg, namely, that 

 published in the latest book on the subject. 



J. E. Harting. 



On M. Mercadier's Test of the Relative Validity of 

 the Electrostatic and Electromagnetic Systems of 

 Dimensions. 



In connection with the clear exposition of the true dimensions 

 of electrical units given by Prof. Kuckerin Nature of the 22nd 

 ult. it is well to bear in mind that Maxwell long before the publi- 



