238 



NATURE 



[July 7, 1829 



lately. Subject to these conditions, it is shown that the possible 

 dimensional valuer of /* and k are eight in number. Of these 

 only two lead to intelligible results. These are — 



and 



(1) M = M(XYZ)-i and k = M-i XYZ-iT\ 



(2) /x = M-iXYZ-iT- and k = M(XYZ)-i. 



According to (i), yu is the density of the medium, electrical energy 

 is potential, and magnetic energy kinetic. By (2), /> is the 

 <lensity of the medium, electrical energy is kinetic, and magnetic 

 ■energy potential. Full interpretations of the dimensional fonnuloe 

 of all the electro-magnetic quantities, as obtained in accordance 

 with the above conditions, are given in the paper. Prof. S. P. 

 Thompson said the paper was a very important one, and thought 

 t he idea of finding dimensions for /x and k which would rationalize 

 the ordinary dimensional formulas a great step. The use of 

 vectors was a valuable feature, whilst the employment of X, Y, 

 and Z instead of L removed many difficulties connected with 

 dimensional formulae. Other difficulties might be cleared up by 

 paying attention to the signs of the vector products and quotients, 

 and to the order in which the symbols were written. Another 

 important matter was the use of Mr. Heaviside's " rational 

 units," a system which merited serious attention. In conclusion, 

 Prof. Thompson expressed a hope that, in accordance with the 

 resolution of the Electrical Congress at Frankfort, both perme- 

 ability and specific inductive capacity should be designated by 

 Greek symbols. Prof. O. Henrici expressed his admiration of 

 the way in which the subject had been treated in the paper. He 

 had long held that clear ideas of physical quantities were best 

 got by vectorial methods. He also congratulated the author on 

 his treatment of plane and solid angles as concrete quantities. 

 In a communication addressed to the Secretaries, Prof. O. J. 

 Lodge remarked that physicists in England were more or less 

 familiar with the advantages of retaining /* and I- in dimensional 

 expressions before Prof. Rucker's paper of February 1889 

 brought the matter closely home to students. The system of 

 mechanical dimensions sufjgested for electrical quantities in an 

 Appendix to " Modern Views of Electricity " was not put forth 

 as the only one possible, but as one having certain probabilities 

 of truth in its favour. Prof. Riicker said that, although Mr. 

 Williams and himself had talked over certain minor points in 

 the paper, the main ideas brought forward were quite original, 

 having been fully developed by Mr. Williams before he men- 

 tioned the subject to him (Prof. Riicker). — A paper on molecular 

 forces, by Mr. W. Sutherland, communicated by Prof. Carey 

 Foster, was taken as read. The Chairman announced that both 

 this paper and that of Mr. Williams would be printed in the 

 Philosophical Magazine during the long vacation, so that they 

 could be fully discussed early next session. 



Linnean Society, June 16. — Prof. Stewart, President, in 

 the chair. — Mr. F. Enock exhibited some specimens of the 

 Mustard Beetle, and gave an account of its recent depredations 

 as observed by himself. So numerous was it that in walking 

 down a single row of mustard, a distance of sixty-five yards, he 

 had captured with a butterfly net upwards of 15,000, as he sub- 

 sequently ascertained by counting a portion and weighing the 

 remainder. The crop of mustard thus affected he regarded as 

 destroyed. — Mr. R. I. Pocock exhibited and made some re- 

 marks upon a species of Peripatus {P. juliformis) from St. 

 Vincent, of which five specimens had been collected by Mr. H. 

 H. Smith for the Committee investigating the fauna and flora 

 of the Lesser Antilles. The species was originally described so 

 long ago as 1826, by the Rev. L. Guilding {Zoological Journal, 

 vol. ii. ), but from that time until the present no additional 

 specimens had been procured there. As Guilding's types had 

 been lost, and his descriptions are wanting in detail, this re- 

 discovery was of considerable interest. — Mr. George Murray 

 exhibited and described the type of a new order ot Algos, to 

 which the name Splachnidium rugosuin was given. — A paper 

 was read by Prof. J. R. Henderson, entitled " Contributions to 

 Indian Carcinology," and embodied an account of several little- 

 known Crustaceans, and descriptions of some new species. — 

 Mr. H. B. Guppy read a paper on " The Thames as an Agent in 

 Plant Dispersal," in which several interesting facts were brought 

 out, the observations being illustrated by specimens collected by 

 the author, and a useful record given of the effects of exposure 

 to sea-water, and of freezing, upon the germinating power of 

 seeds. — Prof. F. Oliver gave an abstract of observations made 

 by Miss M. F. Ewart, on some abnormal developments of the 

 flowers of Cypripedium, illustrated by effective diagrams in 



NO. II 84, VOL. 46] 



coloured chalk. — Mr. R. I. Pocock contributed some " Supple- 

 mentary Notes on the Fauna of the Mergui Archipelago," the 

 result of his examination of some fresh material which had 

 lately come to hand.— The evening was brought to a close by an 

 exhibition by Mr. Carruthers, with the aid of the oxy-hydrogen 

 lantern, of some beautiful shdes of sections of fossil plants. A 

 second series, zoological, exhibited by the President, included 

 several minute organisms of extreme interest. — This meeting 

 brought the session of 1891-92 to a close. 



Anthropological Institute, June 21.— Edward B. Tylor, 

 F.R.S., President, in the chair. — Dr. R.Wallaschek read a paper 

 entitled " An Ethnological Inquiry into the Basis of our Musical 

 System. " In the course of the paper he pointed out that harmony 

 is not a modern European invention, but known to many savage 

 tribes, and even to the Hottentots and Bushmen. A regular 

 bass accompaniment (to distinguish it from songs in harmonious 

 intervals) is far more seldom to be met with, as the extreme 

 simplicity of primitive songs does not admit of much variety in 

 accompaniment. On the other hand, some savage tribes (Hotten- 

 tots, Malays, Negroes) show an astonishingly great talent in 

 accompanying European tunes by ear. Both keys, the major as 

 well as the minor, occur in the songs of primitive races. Minor 

 chords also occur occasionally. There is no internal connection 

 between a peculiar key and a peculiar mood or disposition of 

 mind. The diatonic scale does not seem to be a more recent 

 invention than the pentatonic. The most ancient diatonic 

 division is to be met with in instruments (pipes, flutes) of the 

 Stone period. This early occurrence seems to be due to the fact 

 that the diatonic scale is the most natural for the player's fingers, 

 while it is at the same time the most effective. The diatonic system 

 is neither an "artistic invention," nor a " scientific discovery," 

 nor is it " natural " for the voice or the ear, nor based upon the 

 laws and conditions of sounds, but it is the most natural for the 

 hand, and the most practical for playing instruments. — Prof. 

 Basil Hall Chamberlain then read a paper on some minor 

 Japanese religious practices. After mentioning various mis- 

 cellaneous usages and superstitions, the author treated chiefly of 

 Japanese pilgrims and their ways, illustrating his remarks by an 

 exhibition of a large collection of charms, sacred pictures, pil- 

 grims' dresses, &c., brought together partly by himself, partly 

 by Mr. Lafcadio Hearn. The collection included articles from 

 the Shinto shrines of Ise and Izumo, from the "Thirty-three 

 Holy Places" of Central Japan, from the " Eighty-eight Holy 

 Places" of the island of Shikoku, from the temple of Asakusa 

 in Tokyo, &c. The most curious was a s-acred fire-drill from the 

 great Shinto shrine of Izumo. This, together with a few of the 

 other articles, has been presented by Prof. Chamberlain to the 

 Pitt- Rivers Museum at Oxford. Another feature of the paper 

 was the translation given of a Buddhist legend explaining the 

 origin of the pilgrimage to the "Thirty-three Holy Places," and 

 of some of the hymns intoned by the pilgrims. 



Geological Society, June 22.— W. H. Hudleston, F.R.S., 

 President, in the chair. — The following communications were 

 read : — Contribution to a knowledge of the Saurischia of 

 Europe and Africa, by Prof. H. G. Seeley, F.R.S. The 

 Saurischia are defined as terrestial unguiculate Ornithomorpha, 

 with pubic bones directed downward, inward, and forward to 

 meet in a ventral union. The forms of the pelvic bones vary 

 with the length of the limbs, the acetabulum becoming perforate, 

 the ilium more extended, the pubis and ischium more slender, 

 and the sacrum narrower as the limb-bones elongate. The 

 order is regarded as including the Cetiosauria, Megalosauria, 

 and Aristosuchia or Compsognatha. The Cetiosaurian pelvis 

 has been figured in the Quart. Journ. Geol. Soc. ; and a restora- 

 tion is now given of the pelvis in Megalosaurus, Slreptospondyhis, 

 and Compsognathus. The characters of the skull are evidenced 

 by description of the hinder part of the skull in Megalosaurus 

 found at Kirklington, and preserved in the Oxford University 

 Museum. In form and proportions it closely resembles Cerato- 

 saurus, and the corresponding region of the head in Jurassic 

 Ornithosauria. The brain-cavity and cranial nerves are de- 

 scribed, and contrasted with those of Ceratosaurus. The skull 

 in Cetiosauria, known from the American type Diplodocus, i-* 

 identified in the European genus Belodon, which is regarded as 

 a primitive Cetiosaurian. Part 2 discusses the pelvis of Belodon, 

 restored from specimens in the British Museum, and regarded 

 as Cetiosaurian. A restoration of the shoulder-girdle is made, 

 and found to resemble that in Ichthyosaurs, Anomodonts, and 

 Dinosauria. The vertebrae in form and articulation of the ribs 



