MARCH 28, '907] NA TURE 509 molecule of extraordinary lability. - The first product of such polymerisation, which might be, as the author suggests, the aldehvde of aspartic acid, would further condense so as to form a body having the formula ascribed by Libprkuhn to the simplest protein. This substance, "primitive peptone," by polymerisation of two molecules might form albumoses, and by the union of three molecules might form albumen. Although the facts brought together by the author are interesting, and although we must grant the possibility of aldehvde groups existing in some parts of the protein molecule, and perhaps being responsible for some' of the chemical interactions which occur in the living cell, the new facts brought forward are too trivial effectively to modify our opinion on the structure of the protein molecule, which is based on the solid work of Fischer and his pupils., La Decouverte de l'Anneau de Saturne par Huygens. By Jean Mascart. Pp. 58. (Paris : GauthierVillars, 1907).- Price 2 francs. IN this small volume of 58 pages M. Mascart tells the history of the discovery of Saturn's rings from the time of Galileo's dramatic anagram concerning the altissimam planetanl, and his subsequent tragic disappointment and despair, to the time when, after many questionings and discussions, Huygens finally established his accepted theory. This history is most interesting, and inchides-a number of extracts from Huygens's corespondence on the subject, showing us how he had :to fight for the acceptance of his theory and then had to fight again for the vindication of his priority in the matter. 'The numerous reproductions of original drawings by Gassendi, Helvetius, Riccioli, Huygens, . Wallis, and others give an additional interest Zo the work, which is concluded by a lucid recapitulation of the later theories, such as that of Otto Struve, and discoveries concerning Saturn's unique appendage. W. E. R. German Science Reader. Part i. Mathematics, Physics, and Chemistry. Compiled by C. R. Dow. Pp. 85. (London : J. M. Dent -and Co., 19o6.) Price 2s. TWENTY pages of this book are devoted to mathematics, twenty-three, to physics, nineteen to chemistry and the remainder to a vocabulary of words not usually found in elementary class-books of German. " he mathematical portion is a synopsis of principles of mathematics . with enunciations of problems, while the two remaining sections consist of definitions and descriptions of some physical and chemical properties of matter. Any student of science who has an elementary knowledge of the German language should be able to read the book with the aid of the vocabulary, and the task would be more to his taste than reading or translating Grimm's or Andersen's fairy-tales. No grammatical rules are given, as instruction in these is assumed to have been obtained in an earlier course. Cerusc et Blanc de Zinc. By M. G. Petit. Pp. 154. Preparation mecanique des Minerais. Resume pratique. By F. Rigaud. (Paris : Gauthier Villars and Masson et Cie., n.d.) BOTH these volumes are publications in the now well-known " Encyclopedie Scientifique des AideM'IBmoire." The first deals with the preparation and use in painting of white lead and zinc white re*pectively. The second book provides a practical accdunt of the various processes in use for the mechanical, preparation of ores by separating them f rot11 their stony matrix. NO. 1952, VOL. 75] 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 intended-for this or any other part of NATURE. No notice is taken of anonymous communications.] The Ballot-Box. IN reference to the weight-judging competition, Mr. Gallon says that " the average competitor was probably as well fitted for making a just estimate of the dressed weight of the ox as an average voter is of judging the merits of most political issues on which he votes." These competitions are very popular in Cornwall ; but I do not think that Mr. Gallon at all realises how large a percentage of the voters-the great majority, I should suspect -are butchers, farmers, or men otherwise occupied with cattle. To these men the ability to estimate the meatequivalent weight of a living animal is an essential part of their business ; and, as an instance of their training, I may mention that one of the butchers here has a son under thirteen years of age who is an adept at this vArk, and is already, I am told, one of the best weight-judges in the district. This boy has been trained to it by his father, and already surpasses his instructor. Moreover, many of the competitors doubtlessly compete frequently, compare notes afterwards, and correct future estimates by past experience. Now the point of all this is that, in so far as this state of things prevails, we have to deal with, not a vox populi, but a vox expertorunt. - I am afraid -that the majority of such competitors know far more of their business, are far better trained, and are better fittedto form a judgment, than are the majority of voters of-any party, and of either the uneducated or the so-called " educated " classes. I heartily wish that the case were otherwise. F. H. PERRI-COSTE. Polperro, Cornwall, March 21. I INFERRED that many non-experts were among the competitors, (1) because they were too numerous (about Boo) to. be mostly experts ; (2) because of the abnormally wide vagaries of judgment at either end of the scale ; (3) because of the prevalence of a sporting instinct, such as. leads persons who, know little about horses to bet on races. But I have no facts whereby to test the truth of my inference. It would be of service in future competitions if a line headed " Occupation " were inserted 'in the cards, after those for the address. FRANCIS GALTON. MR. HOOKER, in NATURE of March 21, seems not to have quite appreciated my principal contention in the letters "One Vote, One Value" and " Vox Populi " of February 28 and March 7 respectively. It was to show that the verdict given by the ballot-box must he the Median estimate, because every other estimate is condemned in advance b_y a majority of the voters. This being the case, I examined the votes in a particular instance according to the most appropriate method for dealing with medians, quartiles, &c. I had no intention of trespassing into. the technical and much-discussed question of the relative merits of the Median and of the several kinds of Mean, and beg to be excused from not doing so now except in two particulars. First, that it may not be sufficiently realised that the suppression of any one value in a series can only make the difference of one half-place to the median, whereas if the series be small it may make a great difference to the mean ; consequently, I think my proposal that juries should openly adopt the median when estimating damages, and councils when estimating money grants, has independent merits of its own, besides being in strict accordance with the true theory of the ballot-box. Secondly, Mr. Hooker's approximate calculation from my scanty list of figures, of what the mean would be of all the figures, proves to be singularly correct ; he makes it 1196 lb. (which is the mean of the deviates at 5, 15, 95), whereas it should have been 1197 lb. This shows well that a small orderly sample is as useful for calculating means as a very much larger random sample, CIibPDF -