April 21, 192 1] 



NATURE 



253 



hydric alcohol was obtained, the reduction being 

 apparently interfered with by the production of formic 

 acid and a pentose. — W. E. Hughes : The forms of 

 electro-deposited iron and the effect of acid upon its 

 structure. Part i. : Deposits from the chloride bath. 

 Structures found in iron deposits formed in chloride 

 baths are varieties of two general types, the normal 

 and the fibrous. The type obtained depends upon 

 conditions prevailing during deposition, the fibrous 

 type being characteristic of deposits formed in (a) acid 

 and (b) agitated solutions. Macroscopic features cor- 

 respond to definite microscopic structure. 



Zoological Society, April 5. — Prof E. W. MacBride, 

 vice-president, in the chair. — G. J. Arrow : A revision 

 of the Melolonthine beetles of the genus Ectinohoplia. — 

 J. H. Lloyd : Abnormalities in the common frog 

 (Rana tempararia). — S. Hirst : Some new and little- 

 known Acari, mostly parasitic in habit. The author 

 illustrated his paper by exhibiting under microscopes 

 (i) a preparation of a Sarcoptid mite (Otodectes 

 cynotis. var. cati) showing the well-developed system 

 of tracheal tubes, and (2) a preparation of the mite 

 (Tarsonemus Woodi) from bees affected with Isle of 

 Wight bee disease. — Dr. C. F. Sonntag : The com- 

 parative anatomv of the tongues of the Mammalia. 

 III., Fam. 2, Cercopithecidas : with notes on the 

 comparative physiology of the tongues and stomachs 

 of the Langurs. 



Linnean Society, .April 7.— Dr. A. Smith Woodward, 

 president, in the chair. — H. W. Monckton : The dis- 

 tribution of Taraxacum erythrospennuni, Andrz., in 

 the south-east of England. The author explained that 

 he had for some years noticed a small form of dande- 

 lion with deeply cut leaves and red seed growing 

 abundantly on a football ground at \A'ellington College, 

 Berkshire. It belongs to the group of varieties named 

 erythrospermum. The geological formation is Upper 

 Bagshot Sand (Barton Beds). He had seen the same 

 variety on the similar sandy soil of Puttenham Heath. 

 Surrev (Lower Greensand), on the Thames Gravel 

 near Old Windsor, Berkshire, and on walls at West 

 Drayton and other places. It is not confined to areas 

 of sand or gravel, for the author exhibited specimens 

 from the London Clay of .Ashtead Common, near 

 Epsom, Surrey. — R. A. Malby : A miniature alpine 

 garden from January to December. Amongst the 

 subjects shown in lantern-slides by the lecturer mav 

 he mentioned Saxifraga Burser'ana. S. Grisebachii. 

 S. Striburyi. S. longifoUa, S. Cotyledon, var. islan- 

 dica. Anemone vernalis. A. sulhhurea. Nymphaea 

 Mooreana. Primula frondosa. P. dentictilata, P. mar- 

 ginata, P. Jul'ae, Iris sibirica. I. gracilipes. Cam- 

 panula Allionii. C. pusilla, C. garganica. Shortia 

 galaci folia, S. uniflora. Petrocalli'i pyrenaica. Crocus 

 speciosus. Narcissus Johnstoni. N. monofyhylliis, N. 

 friandriis. A'', minimus, Oxalis enneaphylla, and O. 

 lobafa. 



Physical Society, April 8.— Mr. W. R. Cooper in the 

 chair. — Dr. W. J. H. Moll : A new registering micro- 

 photometer. A diminished image of a slit, on which 

 the filament of a half-watt lamp is focussed, is pro- 

 jected by a microscope objective on the photographic 

 plate or other object of which the absorption is to be 

 measured. A second similar objective focusses an 

 image of the slit, magnified uo to its original size, 

 on a second sltt behind which is mounted a sensitive 

 thermopile of the author's own design connected to 

 an improved D'Arsonval galvanometer. The photo- 

 graphic plate is given a slow motion at right angles 

 to the beam of light, and the spot from the galvano- 

 meter is focussed on a rotatinft drum of photographic 

 oaper. The arrangement is dead beat and so quick 

 in response that intensitv f^virves of close spectrum 



NO. 2686, VOL. 107] 



lines, Zeenian triplets, etc., are accurately recorded. — 

 Sir W. H. Bragg: Application of the ionisation 

 spectrometer to the determination of the structure of 

 minute crystals. Crystals in the form of powder can 

 be examined by the ionisation method. The powder 

 is pasted on a flat surface and placed on the spectro- 

 meter table in the position ordinarily occupied by the 

 face of a single crystal. .\ bulb current of i milli- 

 anipere is sufficient to give satisfactory records. — H. 

 Parry : A balance method of using the quadrant 

 electrometer for the measurement of power. The 

 method involves the use of a potential-divider across 

 the supply circuit, and a standard non-inductive re- 

 sistance in series with the load. An ammeter and a 

 voltmeter are employed to measure the supply voltage 

 and the load current. 



Dublin 

 Royal Dublin Society, March 22.— Dr. F. E. Hackett 

 in the chair. — H. A. Lafferty : The "browning" and 

 "stem-break" disease of cultivated flax caused by 

 Polyspara lini, n. gen. et sp. In the "stem-break" 

 phase of the disease the stems of affected plants 

 become partially or entirely broken across a little 

 above ground-level comparatively earlv in the season, 

 and affected plants generally fall over and die pre- 

 maturely. In "browning" the upper portions of the 

 plants in particular exhibit numerous diseased areas* 

 this takes place about pulling time. .A fungus. Poly- 

 spora lini, n. gen. et sp., was isolated, and proved 

 to be the cause of both phases of the disease. The 

 seed is also attacked, and transmission of the disease 

 occurs by sowing infected seed. The fungus is widely 

 distributed. No means of carrying out seed disinfec- 

 tion on a practical scale have been devised. — H. H. 

 Poole : The electrical conductivitv of some dielectrics. 

 .\ large, steady potential difiference obtained by 

 thermionic rectifying valves was applied to the oppo- 

 site faces of a thin sheet of the dielectric which was 

 kept at a constant known temperature in an oven. 

 The potential difference was measured bv a rotating 

 contact-maker, alternately charging a small condenser 

 and discharging it through a dead-beat galvanometer. 

 The conduction current was measured by a sensitive 

 galvanometer. The logarithm of the electrical con- 

 ductivity when plotted against the potential gradient 

 gave a set of right lines, corresponding to different 

 temperatures, in the case of glass. With mica a 

 greater range of gradient was available, and the lines 

 exhibited slight curvature. 



Paris. 



Academy of Sciences, March 29. — M. Georges Lemoine 

 in the chair. — M. Hamy : The approximation of func- 

 tions of large numbers. — C. Deperet and P. Fallot : 

 The age of the lignite formations of the Island of 

 Majorca. — C. E. Guillaume : The compulsory adoption 

 of the metric system by the Japanese Empire. The 

 metric system has been legal in Japan since 1893, 

 and is now compulsory. The system will also be 

 adopted shortly in China and Siam.- — C. E. Traynard r 

 Certain singular hyper-elliptic surfaces. — J. Andrade r 

 The optical determination of rolling resistance. — P. 

 Le Holland : The movement of a pendulum with elastic 

 suspension.— L. and E. Bloch : Some spark spectra in 

 the extreme ultra-violet. The ultra-violet spark 

 spectra of zinc, cadmium, and lead are given for 

 wave-lengths between the limits i8^o and 1400. — M. 

 de Broglie : Corpuscular spectra. The laws of photo- 

 electrical emission for high frequencies. — L. Bull r 

 The brightness of the electric spark. The photometric 

 method based on the ohotographic comj>arison with 

 an electric arc is used, taking the duration of the 

 spark exposure as 1/500,000 second. The actinic 



