August 29, 1895] 



NA TURE 



413 



LETTERS TO THE EDITOR. 



( The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertah,- 

 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.'\ 



The University of London. 



I AM anxious to make it clear that what Sir John Lubbock 

 has sprung upon us is a radical change in the procedure of Con- 

 vocation. 



The object can only be, it appears to me, to obtain a reversal 

 <if its policy. .\s a political exjiedient it is, therefore, very similar 

 to the action of those politicians who for analogous reasons 

 would change the constitution of the House of Lords. 



Sir John now defines what he calls his " suggestion" in the fol- 

 lowing words : — " That in voting on the new Charter, members 

 of Convocation should do so 'as at a senatorial election,' i.e. 

 by voting ])apers." I call this a radical change in the procedure 

 -of Convocation. 



I put aside the not immaterial point that as a Statutory Com- 

 mission is a delegation from Parliament, the result of its labours 

 will not be embodied in a Charter, but will be virtually in effect 

 an Act of Parliament when approve<l by that body. 



Sir John has made the following statements about his "sug- 

 gestion " : — 



(i) "I am not asking that any privilege which they do not at 

 present possess should be conferred upon my constituents, but 

 ■only supporting what is now their legal right . . . This right 

 I know they highly value" (N.A.TURE, July i8, p. 269). 



(2) " It is the law at present " (NATURE, August 8, p. 340). 



The words which I have put in italics are definite and explicit, 

 and are, of course, in flat opposition to my repeated statement 

 that Sir John's suggestion amounts to a fundamental and, indeed, 

 revolutionary change of procedure. This change consists in 

 extending the mode of voting in a senatorial election to other 

 matters. Now the mode of voting at a senatorial election is 

 prescribed by the 21st clause of the Charter, which is printed in 

 Nature for July 25, p. 296. It embraces two ver>' important 

 points, first, the right of absent members to vote at all is not 

 absolute but only permissive. The words are: " Power to the 

 Convocation, if it shall think fit, to enable absent members of 

 the Convocation to vote on such nominations . . . by voting 

 papers." Secondly, this permissive right is strictly limited by 

 the words '* but not so to vote on any other matter.^^ 



It is upon this vital discrepancy between Sir John's statements 

 <juoted above and the provisions of the Charter that I think it is 

 imperative that he should give some explanation. This demand 

 on my part he is pleased to call an "attack." Well, however 

 that may be, he at least ow-es it to himself to meet it. 



I trust, however, that I have now made it clear, and even to 

 ■Sir John, that his "suggestion " is not the law, but that, further, 

 it involves the abrogation of a portion of the Charter. I think 

 as a member of Convocation that in making such a proposal 

 without consulting that body he has exceedetl his functions as 

 our Parliamentary representative. At any rate it mu.st, I think, 

 be admitted that he is making short work of the " right" which 

 his " constituents highly value." (Nature, August 8, p. 340.) 



I am unwilling to prolong a painful discussion. But as .Sir 

 John is pledged to bring forward his "suggestion'' in Parliament, 

 which of course can incorporate it in the Bill, if it thinks proper, 

 ,it seems to me of extreme importance to dissipate his contention 

 that it is already the " law." W. T. Tiiiselto.n-Dyer. 



Kew, .-August 23. 



The Nomenclature of Colours. 



The interesting article of Mr. J. H. Pillsbury, published in 

 your last number, recalls to me a passage in my autobiography, 

 which, though it is already in print, will not be issued until after 

 my death. .-\s bearing on the question Mr. Pillsbury raises, 

 this passage may, perliaps with advantage, be ]iul)lished in 

 .advance. The plan suggested aims at n<j such scientific nicety 

 -of discrimination or naming .as that he proposes, but is one 

 which is applicable with the means at present in use. It is, 

 as will be ]ierceived, based on the old theory respecting the 

 primary colours; but whatever qualification has to be made in this, 

 .need not atTect the method described. The passage is as 

 follows ; — ■ 



" I mention it here chiefly for the purpose of introducing an 



NO. 1348, VOL. 52] 



accompanying thought respecting the nomenclature of colours. 

 The carrying on of such a scheme would be facilitated by .some 

 mode of specifying varieties of tints with definiteness ; and my 

 notion was that this might be done by naming them in a manner 

 analogous to that in which the points of the compass are named. 

 The subdivisions coming in regular order when ' boxing the 

 compass,' as it is called, run thus : — North, north by east, 

 north-north-east, north-east by north, north-ea.st ; north-east by 

 east, east-north-east, east by north, east. Applying this method 

 to colours, there would result a series standing thus : — Red, red 

 by blue, red-red-blue, red-blue by red, red-blue (purple) ; red- 

 blue by blue, blue-red-blue, blue hy red, blue. And in like 

 manner would be distinguished the intermediate colours between 

 blue and yellow and those between yellow and red. Twenty- 

 four gradations of colour in the whole circle would thus have 

 names ; as is shown by a diagram I have preserved. Where 

 greater nicety was desirable, the sailor's method of specifying a 

 half-point might be utilised — as red-red-blue, half-blue ; signify- 

 ing the intermediate tint between red-red-blue and blue-red by 

 red. Of course these names would be names of pure colours 

 only — the primaries and their mixtures with one another ; but 

 the method might be expanded by the use of numbers to each : 

 I, 2, 3, signifying proportions of added neutral tint subduing 

 the colour, so as to produce gradations of impurity. 



" Some such nomenclature would, I think, be of much service. 

 At present, by shopmen and ladies, the names of colours are 

 used in a chaotic manner — violet, for instance, being spoken of 

 by them as purple, and other names being grossly misapplied. 

 As matters stand there is really no mode of making known m 

 words, with anything like exactness, a colour required ; and 

 hence many impediments to transactions and many errors. In 

 general life, too, people labour under an inability to convey true 

 colour-conceptions of things they are describing. The system 

 indicated would enable them to do this, were they, in the course 

 of education, practised in the distinguishing and naming ot 

 colours. If, by drawing, there should be discipline of the eye in 

 matters of form, so there should be an accompanying discipline 

 of the eye in matters of colour." 



Were some authoritative body to publish cards representing 

 these various gradations of colour, arranged as are the points 

 of the compass, each division bearing its assigned name, as above 

 given, such cards might serve as standards ; and any one pos- 

 sessing them would be able to indicate, within narrow limits, 

 to a shopkeeper or manufacturer, the tint he or she wanted. Ot 

 course to complete the method it would be needful that there 

 should be a mode of indicating gradations of intensity, and if 

 the numbers i, 2, 3, were appended to indicate the degrees of 

 impurity by mixture with neutral tint, a, b, c, might be used to 

 signifj' the intensity or degree of dilution of the colour. 



\'ery possibly, or even probably, this idea has occurred to 

 others, for it is a very obvious one. Herbert Spencer. 



The Mount, Westerham, July 23. 



Clausius' Virial Theorem. 



The above-named theorem, which appeared in the /V;//. Mag. 

 for August 1S70, much .as it is now used in connection with the 

 kinetic theory of gases, received little, if any, attention in 

 England for some time after its introduction. Apparently the 

 theorem was accepted without hesitation or discu,ssion, and, as 

 far as I can learn, neither on its first introduction or since has it 

 received any adverse criticism, or, in fact, any criticism whatso- 

 ever. My object in writing this letter is, in the first pKace, to 

 direct attention to the argtiments used by Clausius to establish 

 his theorem, which appear to me to be unsound, and secondly, 

 by applying a simple test case, to show that the theorem itself is 

 not true. 



Clausius first proves the following equation. 



itj^dl^ 2lj^dP dtjj^dt) 



If for the moment, for the sake of simplicity, we divide bol 

 sides of the equation by — , we get 



and this may be written 



«.v = / xdii + I ttdx. 

 Jo Jo 



