March 29, 1906] 



NA TURE 



5 2 7 



Company during the period when the Central London Rail- 

 way was shut down, were also clearly shown on magneto- 

 graph curves. The effects are much greater on the vertical 

 force than on the horizontal force or the declination. A 

 second system of investigation was to connect the earth- 

 plates through the primary of a transformer, the secondary 

 terminals of which were connected to a sensitive moving- 

 coil galvanometer of suitable period and damping. The 

 galvanometer recorded a ballastic throw for each movement 

 of a tramway controller, while the slower variations due 

 to magnetic storms were without effect. A telephone 

 similarly connected gave a perceptible sound for each con- 

 troller movement. 



Royal Meteorological Society, March 21. — Mr. R. 

 Bentley, president, in the chair. — South Africa as seen by 

 a meteorologist : Dr. H. R. Mill. The lecture was illus- 

 trated by a series of lantern-slides from photographs taken 

 during the tour of the British Association in 1905. The 

 places visited included Cape Town, Table Mountain, 

 Durban, Maritzburg, Ladysmith, Johannesburg, Pretoria, 

 Bloemfontein, Kimberley, Bulawayo, the Matoppo Hills, 

 the Victoria Falls of the Zambesi, Salisbury, Umtali, and 

 Beira. During the return journey, Mombasa, Cairo, and 

 the Suez Canal were visited. Photographs were shown of 

 meteorological stations in many of the places named, and 

 the views of the scenery were selected to bring out the 

 climatic features. 



Cambridge. 



Philosophical Society, February 12. — Mr. F. Darwin 

 in the chair. — Notes on cycads : with exhibition of a rare 

 species acquired by the Botanic Garden : A. C. Seward. 

 The author exhibited a plant of Cycas Micholitzii, Dyer, 

 recently obtained by the curator of the Botanic Garden 

 from Messrs. Sanders and Sons. This species was dis- 

 covered by one of Messrs. Sanders' collectors, Mr. YV. 

 Micholitz, in Annam, and described last year by Sir 

 William Thiselton-Dyer in the Gardeners' Chronicle, 

 August 19, 1905, p. 142. The author directed attention to 

 the importance of cycads as representing scattered survivals 

 from a remote past, and as plants which still retain traces 

 of ancestral characters. — Respiration and vitality : F. F. 

 eiackman. — Experiments on the hybridisation of barleys : 

 R. H. Biffen. The behaviour of the more important 

 differentiating characters to be found among the varieties 

 of barley ha* been investigated. — A comparison of the 

 results from the Falmouth declination and horizontal force 

 magnetographs on quiet days in years of sun-spot maxi- 

 mum and minimum : Dr. Chree. 



February 26. — Dr. Fenton, vice-president, in the chair. — 

 An indicator for strong acids and bases : Dr. Fenton. 

 Reference was made in previous communications by the 

 author to a new condensation product, derived from methyl- 

 furfural, which has the molecular formula C^HjO,. It 

 was pointed out that this substance may have useful appli- 

 cations in organic analysis, since it gives highly character- 

 istic colour-reactions with certain classes of compounds, 

 such as amines and ureas. In the present paper it is 

 shown that the reagent serves also as an indicator of 

 alkalinity, and further, that by condensation with urea a 

 colourless base is obtained which is turned blue with acids, 

 and may therefore be used as an acid indicator. — The 

 action of acid chlorides of acetylenic acids on ketonic com- 

 pounds : S. Ruhcmann. The paper gives an account of 

 experiments undertaken with the view of supporting the 

 constitution of the product of the reaction between phenyl- 

 propiolyl chloride and acetylacetone, and the formula of 

 the substance formed from it under the influence of 

 secondary bases. The properties of this substance have 

 been found to resemble in every respect those of oxalvldi- 

 benzylketone. — The dihvdrotetrazines : S. Ruhcmann. 

 The author has extended his research on tetrazoline, and 

 found that the properties of dimethyltetrazoline differ most 

 markedly from those of tetrazoline. — The velocity of trans- 

 formation of sugars by alkalies : R. S. Morrell and A. E. 

 Bellars. Aqueous solutions of glucosates, fructosates, and 

 mannosates of guanidine, potash, and soda undergo slow 

 change indicated by a decline in the rotatory power. The 

 velocity of change, as measured by the diminution of the 



optical activity of the solutions, is that of a unimolecular 

 reversible reaction. Under the conditions of the experi- 

 ments glucose and fructose are mutually transformable, the 

 production of mannose and acids proceeding at such a slow 

 rate that glucose and fructose first attain an equilibrium, 

 which is afterwards disturbed by the appearance of steadily 

 increasing quantities of saccharinic acid. In the case of 

 guanidine mannosate solutions, the velocity constant 

 obtained from observations of the fall in rotatory power 

 has nearly the same value as the corresponding one for 

 guanidine glucosate and fructosate, but direct measurement 

 of the rate of disappearance of the mannose gave a very 

 much lower value. — The influence of very strong electro- 

 magnetic fields on the spark spectra of (a) vanadium, 

 (b) platinum and iridium : J. E. Purvis. The field strength 

 was 39980 C.G.S. units. (1) With regard to vanadium, two 

 lines become sextuplets and four lines become quintuplets. 

 There are a number of lines divided into four, whilst the 

 great majority of them become triplets. Also there are a 

 few doublets, and there are about eight lines which do not 

 appear to be affected. The distances of the separated con- 

 stituents from the normal lines were measured, and the 

 value of d\/A 2 calculated ; and it is seen that many of the 

 lines may be expressed by the same formula, the appear- 

 ances of the' undivided lines and the separated constituents 

 and the values of d\!\- being essentially identical. 

 Ul Similarly, with regard to the metals Pt and Ir, there 

 are lines of both metals which may be grouped together 

 as possessing identical dX/K 1 values, and the normal lines 

 and separated constituents of which are similar in appear- 

 ance. (3) In several instances the values of d\!\ 2 for the 

 several constituents seem to be simple multiples of each 

 other. 



Paris. 

 Academy of Sciences, March 19. — M. H. Poincare in the 

 chair. — Observations of nebulae : M. Bigourdan. — The dis- 

 tillation of titanium and the temperature of the sun : Henri 

 Moissan. The boiling point of titanium is very high, and 

 it was necessary to employ a current of 1000 amperes at 

 55 volts in the electric furnace to volatilise it readily. The 

 distilled titanium was obtained on the cold tube mixed with 

 lime, distilled from the furnace body. This lime was re- 

 moved by acetic acid, and the residue was proved by its 

 chemical properties to be titanium. Taking the tempera- 

 ture of the electric arc as 3500° C. (Violle), it is clear from 

 the fact that titanium vapour exists in the sun that the 

 temperature of the sun must be above 3000° C. — Benzyl- 

 and phenylborneols and their products of dehydration : the 

 benzyl- and phenyl-camphenes : A. Haller and E. Bauer. 

 The secondary benzylborneol w-as prepared by the reduction 

 of benzvlcamphor, and its dehydration by phthalic 

 anhydride ; formic acid and pyruvic acid gave rise to the 

 a-benzylcamphene. The tertiary benzylborneol was pre- 

 pared by Grignard's reaction from camphor; its dehydration 

 gave an isomeric /3-benzylcamphene, the properties and 

 derivatives of which are described. — The facies of variation 

 of certain nepheline syenites from the Los Islands : A. 

 Lacroix. — Gennadas, or bathypelagic Peneids : E. L. 

 Bouvier. — The sheet of the Geological Survey, on the scale 

 of 1 : 80,000, dealing with the region of Gap : Michel 

 Levy. — Functions which depend on other functions : Vita 

 Volterra. — Observations of the Kopff comet (19066) made 

 with the bent equatorial of the Observatory of Lyons: J- 

 Guillaume. The observations were made on March 5, 6, 

 and 7. The comet appeared as a nebulous star of 15" 

 diameter and about 105 magnitude. — Observations of the 

 comet 1906ft made at the Observatory of Algiers with the 

 31-8 equatorial : MM. Sy and Villatte. Observations were 

 made on March 5, 6, 7, and 8.- A new solution of the 

 problem of magnetic induction for an isotropic sphere : 

 Tommaso Bossio- — The resistance of emission of an 

 antenna : C. Tissot. A discussion of the most favourable 

 conditions for using a thermal indicator as a receiver of 

 Hertzian waves. — The mechanism of the positive light r 

 P. Villard. The positive column in a Geissler tube is re- 

 garded as a chain of gaseous particles traversed by the 

 current. It still remains to be determined whether the 

 emission, of light is due to the passage of the current or 

 to the progressive dislocation of the chain by the shock 



NO. I9OO, VOL. 73] 



