70 



NATURE 



[November 17, 1904 



1 



SOCIETIES AND ACADEMIES. 

 London. 

 Chemical Society, November 3. — Prof. W. A. Tilden, 

 F.R.S., in the chair. — The following papers were read : — 

 Studies on the dynamic isomerism of a- and ;3-crotonic acids, 

 part i. : R. S. Morrell and E. K. Hanson. Preliminary 

 experiments on the freezing points of mixtures of the two 

 acids furnish no evidence as to the existence of a compound 

 of a- and /3-crotonic acids between 100° and 168°, and between 

 15° and 7i°-9. — The constitution of nitrogen iodide : O. 

 Silberrad. In the interaction of zinc ethyl with nitrogen 

 iodide it was found that trimethylamine was produced. This 

 confirms Chattaway's view that the iodide has the con- 

 stitution NH, : Nl,. — The available plant food in soils : 

 H. Ingrle. Extraction with a i per cent, solution of citric 

 acid for seven days renders a soil much less fertile, especially 

 at first, but chemical changes in such soil, during the growth 

 of the plants, gradually render it again capable of supply- 

 ing plant food. — The basic properties of oxygen : compounds 

 of the ethers with nitric acid : J. B. Cohen and J. Gatecliff. 

 It is shown that with aliphatic ethers unstable compounds 

 of the type X,0,HNO, are formed. — Note on the influence 

 of potassium persulphate on the estimation of hydrogen 

 peroxide : J. A. N. Friend. It is shown that a secondary 

 reaction, represented by the following equation, 



H,0,-(-K,S,0, = K,S0,-(-H,S0^-)-02, 

 probably takes place in addition to the main reaction. — ^The 

 influence of sunlight on the dissolution of gold in aqueous 

 potassium cyanide : W. A. Caldecott. — The fractional 

 hydrolysis of amygdalinic acid, iso-amygda!in : H. D. 

 Dakin. — The effect of anhydrides on organo-magnesium 

 bromides, part i., the action of phthalic anhydride on 

 magnesium o-naphthyl bromide : S. S. Pickles and 

 C. Weizmann. — The combustion of ethylene : W. A. Bone 

 and R. V. Wheeler. The principal results of these experi- 

 ments are as follows : — (i) there is no preferential com- 

 bustion of either carbon or hydrogen ; (2) formaldehyde is 

 the most prominent intermediate oxidation product ; (3) 

 there is no separation of carbon or liberation of acetylene. 

 — The decomposition of methylcarbamide : C. E. Fawsitt. 

 The decomposition of methylcarbamide by acids is due to a 

 transformation of the methylcarbamide into methylamine 

 cyanate, which is subsequently decomposed by the acid. — 

 Position isomerism and optical activity ; the methyl and 

 elhyl esters of di-o-, -m-, and -^-nitrobenzoyltartaric acids : 

 P. F". Frankland and J. Harger. The authors describe 

 the preparation and properties of the six esters in question. 

 — The action of nitrogen sulphide on organic substances, 

 part ii. : F. E. Francis and O. C. M. Davis.— Reduction 

 products of a/S-dimethylanhydracetrnebenzil, and condensa- 

 tion products of benzaldehydes with ketones : F. R. Japp 

 and W. Maitland. — Interaction of sodium phenylglycidate 

 with phenylhydrazine : F. R* Japp and W. Maitland. — 

 o-BenzoyI-;8-trimethacetylstyrene : F. R. Japp and W. 

 Maitland, — Olefinic ketonic compounds : S. Ruhemann. 

 — A" -Oleic acid: H. R. Le Sueur. — Action of magnesium 

 alkyl halides on derivatives of camphor : M. O. Forster. 

 — Sulphonchloroalkylamides : F. D. Chattavway. 



Linnean Society, November 3.— Prof. W. A. Ilerdman, 

 F.R.S., president, in the chair. — Mr. G. Claridge Oruce 

 showed specimens of a new British grass, Koeleria 

 valesiaca, Gaud., which he had found in the herbarium of 

 Dillenius at Oxford, and recently re-found in the original 

 locality at Brent Down, Somersetshire. — The Rev. John 

 Gerard, S.J., brought specimens of a proliferous plantain 

 (Plantago major) from the neighbourhood of Clitheroe, 

 Lancashire. — Mr. Frank Crisp brought for exhibition a 

 flower of Schuhertia graveolens, Lindl., an asclepiad, which, 

 deprived of its corolla and with a portion of its calyx cut 

 away, viewed from the side, presented the genitalia in the 

 shape of a skull. — A note on some points in the structure of 

 the gill of the Ceylon pearl-oyster : the President. — Notes 

 on the " sudd " formation of the Upper Nile : A. F. 

 Broun. The author gives a list of the plants forming 

 the mass of vegetation, which, favoured bv the silt 

 brought down by the White Nile, helps to ' block the 

 shallow channels. — Bryozoa from near Cape Horn : A. W. 

 Waters. The paper deals with specimens which were 

 NO. 1829, VOL. 71] 



collected by the French " Mission scientifique du Cap 

 Horn," but were not mentioned by Jullien in his report on 

 the " Bryozoaires " of that expedition, published in 1888. 

 From this material, which Jullien had presumably not 

 handled, Mr. Waters adds twenty-eight species to the 

 original list of fifty-six. He gives further particulars in 

 regard to some of those named by his predecessor, and 

 points out that eight species established by Jullien had 

 been already described under other names. He rectifies 

 two erroneous identifications, enlarges the range of dis- 

 tribution for several species, and for six of them calls to 

 mind that they were first discovered by the Challenger. 



Mathematical Society, November 10. — Prof. H. Lamb, 

 president, in the chair. — The council and officers for the 

 ensuing session were elected. They are as follows : — 

 president. Prof. Forsyth ; vice-presidents. Prof. Burnside, 

 Prof. Elliott, Prof. Lamb ; treasurer. Prof. Larmor ; secre- 

 taries, Prof. Love and Mr. Grace ; other members of council, 

 Mr. Berry, Mr. Campbell, Dr. Glaisher, Dr. Hobson, Major 

 MacMahon, Mr. Mathews, Mr. Western, Mr. Whittaker, 

 Mr. A. Young. — Prof. Forsyth having taken the chair. Prof. 

 Lamb delivered an address on deep-water waves. He re- 

 viewed the theory of the waves produced on deep water by 

 a local disturbance of the surface. The theory developed 

 independently by Poisson and Cauchy had often been re- 

 garded as obscure, and it had never been interpreted com- 

 pletely. The problem has a deeper significance in that it 

 offers perhaps the simplest example of the propagation of 

 waves in a dispersive medium, and was the origin of the 

 theory of group velocity, which has so many applications 

 in various branches of physics. After tracing the history of 

 the problem, the author proceeded to disengage the essential 

 results of the theory from the clouds of analysis in which 

 they had been involved ; he pointed out the connection of 

 the analytical results with the analysis which was used at 

 a later date for the investigation of the phenomena of diffrac- 

 tion ; he traced the forms of the waves due to a local initial 

 elevation both at considerable and at small distances from 

 the source of disturbance ; and he pointed out the significance 

 of the results when interpreted by means of modern notions 

 concerning waves of approximately simple harmonic type 

 and the propagation of groups of such waves. Finally, he 

 discussed the solution of the problem of waves generated by 

 a local and periodic variation of pressure. — The following 

 papers were communicated : — Note on the application of the 

 method of images to problems of vibrations : Prof. Volterra. 

 It is shown how to obtain by means of the method of images 

 a complete solution of the problem of vibrations of a mem- 

 brane, and it is pointed out that although the train of images 

 may be infinite, yet the number of terms in the solution is 

 finite. — The zeros of certain classes of integral Taylor's 

 series, two papers : G. H. Hardy. The nature of the zeros 

 of some particular classes of functions, allied to the ex- 

 ponential function, is determined with much greater pre- 

 cision than can be attained by any of the known general 

 theorems. If ^(n) is an integer when n is an integer, and 

 the increase of 4i{") is regular and sufficiently rapid, there 



are exactly <j>{n) zeros of Stt—t-j within the circle \x ( = (fi(n), 



and their positions can be determined very precisely. In 

 the second paper similar investigations are given for other 



X" 



— is an example. — On the re- 



functions of which 2- 



ducibility of covariants of binary quantics of infinite order ; 

 P. W. Wood. The paper contains the conditions that any 

 covariant linear in the coefficients of each of 5 binary quantic* 

 of infinite order should be expressible in terms of products 

 of covariants of lower total degrees. The reducibility of 

 covariants of degree 4 is determined completely, and certain 

 classes of reducible covariants of degree 5 and weight 

 >(2'-^— i) are discussed. — The linear difference equation 

 of the first order : Rev. E. W. Barnes. The questions to 

 be considered relate to the existence of solutions, their 

 analytical expression, and their place among transcendental 

 functions. These questions are discussed from the point of 

 view of the theory of functions of complex variables, the 

 arguments of the functions which occur in the difference 

 equations being assumed to be complex. — Curves on a 

 conicoid : H. Hilton. — Remarks on alternants and con- 

 tinuous groups : Dr. H. F. Baker. — Expansions of the 



