240 



NATURE 



{July 15, 1880 



conversion of a "stream" into a "tone," and "adding' 

 to the "resonance" of such a converted stream, is very 

 slipshod-writing. On the whole matter of resonance 

 (15. 46) the writer is imsatisfactory. He does not include 

 the cavities between the vocal ligaments and the lid (epi- 

 sjlottis) among the resonating chambers, except in the 

 objectionable passage just cited, and he does not enter 

 into the question of the modification of quality of tone by 

 means of these resonances. By some accident in en- 

 graving Plate XI 1 1, the letter w is placed on the windpipe, 

 as well as on the cartilages of Wrisberg, and the vocal 

 ligaments are not distinct enough. All the figures, XIII. 

 to XVI., seem to be copied from the English edition of 

 Madame E. Seller's "Voice in Singing." It is a pity to 

 waste space in such a little book on controversy. It was 

 liardly necessary to quote Madame E. Seller at length 

 (pp. 8 1-90), and then controvert many of her statements. 

 This only tends to confuse the learner. The result 

 should be given from the author's own obsei-vations, and 

 then, if desired, the points of difference might be explained 

 in a note. Similarly for the controversy about the action 

 of the " wedges " (cuneiform cartilages) on p. 45, which 

 lias no interest or use for a beginner. The space devoted 

 to controverting Mr. Lunn's "Philosophy of Voice" 

 (pp. 52, 69, 70), and to Mr. lUingworth's "hazelnut" theory 

 of the " pockets," and other bits of controversy with Miss 

 SabiUa Novello (p. 30) and Dr. Garrett (p. 32) might also 

 have been saved with advantage. 



It takes much space to point out a few minor blemishes 

 that scarcely detract from the general merits of the book, 

 which is clearly the result of much real work and careful 

 observation. 



OUR BOOK SHELF 

 Keith Johnston's Illustrations of Electricity and Mag- 

 netism. By W. Lees, M.A. (W. and A. K. Johnston, 

 Edinburgh and London.) 

 Messrs. W. and A. K. Johnston have begun an excel- 

 lent work in issuing these four sheets of diagrams in 

 illustration of the fundamental experiments of electricity 

 and magnetism. The subjects are well chosen, and with 

 hardly any exception well drawn and coloured. They 

 will be welcomed by teachers of science classes in schools 

 for their clearness and general excellence. Mr. Lees, who 

 has prepared them, has also issued a specially-written 

 " Handbook " to accompany each sheet. Of these hand- 

 books—though perhaps useful for such pupil-teachers as 

 may have the misfortune to be set to teach a subject in 

 which they have themselves never made a single experi- 

 jj^ent— the less said the better. The writer of them is in 

 bondage to the ideas of half a century ago. Take as a 

 specimen the following statement concerning the Leyden 

 jar : — " Suppose, then, the accumulation of electricity in 

 thejar to proceed, the quantity of free electricity in the inner 

 coating goes on also increasing, until the density of that 

 electricity becomes the same as the density of the electricity 

 of the prime conductor." The italics are the author's 

 own ! This is no more absurd, as a scientific statement, 

 than it would be to say that when a dock-sluice is opened 

 the water rushes in from the higher level until the muddi- 

 ness of the water inside is as great as the muddincss of 

 the water outside ; for the electric equilibrium of two con- 

 ductors no more depends upon the density of their 

 respective charges than does the flow of water upon its 

 degree of turbidity. Yet the writer of this amazing sen- 

 tence styles himself "Lecturer on Natural Philosophy, 

 Edinburgh ' ' ! For the sheets of diagrams themselves we 

 have nothing but praise. 



LETTERS TO THE EDITOR 



[ The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, or 

 to correspond with the writers of, rejected manuscripts. No 

 notice is taken of anonymous eommtinicalior.s. 



[ Tlie Editor urgently requests correspondents to hep their letters as 

 short as possible. The pressure on his space is so great that it 

 is impossible othei-wise to ensure the appearance rcen op com- 

 munications containing interesting and novel facts.\ 



A Fourth State of Matter 



Mr. Crookes has given us optical evidence of the existence 

 of matter in a slate of tenuity known hitherto only indirectly, 

 and considers himself warranted in affirming the discovery of a 

 fourth or ultra-gaseous condition ; yet it can scarcely be con- 

 ceded that he has demonstrated the truth of his views, or that 

 his recent exposition of them has strengthened his position or 

 satisfied the doubts of the .sceptical. It is simply a question of 

 the use or misuse of certain specific terms, and it is difficult to 

 follow the logic which justifies the creation of a " fourth state" 

 by the"attribution of properties not differing essentially from those 

 of matter in its normal condition. Before his contention be 

 granted it should be proved that the substance under experiment 

 possesses properties exclusively and inalienably its own ; as rigidly 

 defined as those which distinguish the solid from the liquid, or 

 the latter Crom the gaseous. 



By the abstraction from his experimental chamber of a large 

 portion of its contents he has enlarged the interstitial spaces of 

 the residual gas, and thus amplified the mean free path of mole- 

 cular vibration from some millionthsof an inch to several inches ; 

 but beyond this extension of the path of oscillation there seems 

 nothing to warrant the opinion that the residual gas is essentially 

 other than it was before. 



If this amplification of the molecular path be the feature relied 

 on for justifying the term "fourth state" — and this seems the 

 only inference— then further travel in this direction brings us to 

 a point easily within our conception, where the contents of the 

 experimental chamber shall not exceed one or two molecules ; 

 and it becomes interesting to know if Mr. Crookes would then add 

 3. fifth to the other states of matter. To do so would seem the 

 inexorable outcome of his reasoning, and inevitably resolves the 

 question into one of the numerical contents of the chamber ; and 

 it rests \\ith him to define the precipe point where the ordinary 

 conditions cease, and the ultra-gaseous commences. 



In gases, whether at the normal density, or rarefied to 3 mm., 

 we have an unbroken continuity of condition ; which, contrasted 

 with the soUd and liquid forms of matter, is noticeable for the 

 bsence of any point whence a new state can be said to originate : 

 would Mr. Crookes assign a vacuum of 0-999 ™ni- o"" o°e of 

 0-00003 mm. as the critical point in the attainment of his " fourth 

 state " or some intermediate density? 



Again, has Mr. Crookes fully recognised the distinction 

 Ijetween the properties of matter per sc and those which are 

 referable to electrical agency as revealed by the experiments of 

 Messrs. De La Rue and Miiller, where the projection of mole- 

 cules against the walls of the containing vessel is attributed to 

 electrification ; or, further, the fact that a tenuity approaching 

 that attained in his experimental chambers has been long familiar 

 to us in the case of steam of very high pressure ? 



Whatever may be the solution of our speculations regarding 

 the ultimate condition of matter, opinion seems unanimous that 

 the concrete form in which it is known to us consists of an 

 aggregation of particles having imuuitable properties and com- 

 position, gaseous bodies being definite molecular groupings of 

 such particles ; and if such be the case, and the chemical charac- 

 ter of the contents of Mr. Crookes' experimental chambers re- 

 mained unaltered, it is difficult, if not impossible, to conceivethe 

 existence of any further condition other thau that produced by 

 the breaking up of the molecule into its component atoms. 

 London, July 9 ^ " 



Geo. E. Newton 



Permanent Record of Foucault's Pendulum Experiment 



Some four years since, while arranging a Foucault's pendulum 

 for use in the class-room, it occurred to me to endeavour to 

 obtain a permanent record of the experiment, and as the results 

 were very good, and the method simple, they may be mterestmg 

 to others. , , , , . , ^ ^ 



The pendulum used was sixteen feet long, the height of my 

 lecture-room at the Massachusetts Institute of Technolgy, and 



