

November i8, 19 15] 



NATURE 



-hl^ 



sensitive towards extraneous orj^^anic matter in the 

 colloidal state. In tap-water the rate of decomposition 

 ••^ fully fifty times that in the purest specimen of water 

 1 L prepared. Previous work upon the thermal decom- 

 osition of H2O2, especially the comprehensive research 

 of Lemoine, must be considered as of doubtful value, 



{as no special precautions appear to have been taken. 

 Physical Society, October 22.— Dr. A. Russell, vice- 

 president, in the chair.— Dr. T. Barratt : The radiation 

 and convection from a heated wire in an enclosure 

 of air. The object was to determine the numerical 

 relation between the radiation and the convection losses 

 from a heated metallic wire or rod placed in a gas at 

 constant temperature. The method consisted in (i) 

 measuring the amount of heat required to maintain 

 the temperature of the wire a given amount (about 

 10° C.) above that of the surrounding gas, the surface 

 of the wire being (a) coated with a dead-black varnish, 

 (fe) uncoated, (2) comparing the radiations from two 

 surfaces exactly similar to (a) and (6) by means of a 

 thermopile. If the total heat lost from unit surface 

 of the wire is a times greater from a " black " wire 

 than from a " bare " one, while the radiation froni 

 the black surface is h times more than from the un- 

 blacked surface, then 



r„__a 

 c a- 



b{a-b) 



- , and -1 = 



I f a- 1 



where r^, r, are the radiations from "black" and 

 *'bare" surfaces respectively, and c is the convection. 

 Of 100 parts of " total heat " lost from a wire at air 

 temperatures, 2-5 consist of radiation for a bare wire, 

 and 12-6 for a "black" wire. At 100° C, these per- 

 centages become 44 and 207 respectively. — Dr. A. 

 Griffitlis : The determination, by the method of diffusive 

 convection, of the coefficient of diffusion of a salt dis- 

 solved in water. The diffusion of matter, like the 

 diffusion of heat, produces convective currents, and 

 there is a diffusive convection akin to thermal con- 

 vection. In the apparatus described the convective 

 flow is of the order of one millionth of a cubic centi- 

 metre per second from the top of one set of difTusion 

 tubes to the top of another set. The top of each set 

 of diffusion tubes is enclosed in a glass vessel con- 

 taining water, and one vessel is connected to the 

 other by means of a long capillary tube. Each set of 

 eight diffusion tubes is of length about 5 cm., and has 

 a total area of cross-section of about 05 sq. cm. The 

 capillary tube is about 150 cm. long, and has a 

 diameter of about i mm. ; and the linear flow of a 

 coloured index, consisting of a feeble solution of 

 uranine, is of the order of 10 cm. per day. The index 

 IS introduced by means of a special four-waj- glass tap. 

 Dr. T. Barratt : The magnitude of the thermal resist- 

 ance introduced at the slightly conical junction of two 

 solids and its variation with the nature of the surfaces 

 in contact. The abrupt fall of temperature caused by 

 the thermal resistance at the slightly conical junction 

 of two solids has been examined, the method consisting 

 in constructing- a "double joint," thus doubling also 

 the thermal resistance effect. In wires of small 

 diameter, the fall of temperature was found to be 

 2^ per cent. This percentage fall of temperature is 

 practically the same at all temperatures of the en- 

 closure (up to 100° C), and is independent of the 

 excess of temperature of the end of the wire above 

 that of the enclosure (at any rate, up to 10° C. or 

 12° C). For wires of greater diameter (6 nun.) the 

 resistance is rather less than for smaller wires. 



Zoological Society, October 26.— Prof. E. \V. Mac- 

 Bride, vice-president, in the chair. — E. (r. Boulenger : 

 The feeding of snakes in captivity. 'Ihe results 



NO. 2403, VOL. 96] 



showed that, with rare exceptions, snakes that refused 

 to feed on dead animals were not more likely to 

 accept them if alive.— Dr. S. F. Harmer : Specimens of 

 Cuvier's whale {Ziphius cavirostris) from the Irish 

 coast. The inclusion of Z. cavirostris in lists of the 

 Cetacek of the British seas appears to rest on the 

 evidence of a single skull obtained by .Sir William 

 Turner from Shetland. By an arrangement made 

 with the Board of Trade in 1912, the British Museum 

 receives telegraphic reports of the stranding of Cetacea 

 on the British coasts. Two of the specimens thus 

 reported have proved to belong to this rare species, 

 and their skeletons have been secured for the museum. 

 — Dr. F. E. Beddard : Taenia striiihionis. Parona, and 

 allied forms. .\ probably new species of Davainea, 

 parasitic in the ostrich (Struthio masaicus), was de- 

 fined. — Prof. S. J. Hickson : Some Alcyonaria and a 

 Stylaster from the west coast of North America. 

 Three new species of Alcyonaria were described. 



Linnean Society, November 4.— Prof. E. B. Poulton, 

 president, in the chair.— E. Heron-Allen and A. Earland : 

 The Foraminifera of the west of Scotland, collected 

 by Prof. W. A. Herdman, on board the s.y. Rima, 

 1913. The authors directed attention to the rich- 

 ness of the material, which on examination had yielded 

 nearly 330 species and varieties, among which two 

 species and several varieties are new to science. About 

 thirty species are new to Britain, whilst many are 

 recorded for the second time only. Several of the 

 species recorded in the authors' Clare Island mono- 

 graph as new to science, or to Britain, are included 

 in the latter category. The material consisted of 

 shore-gatherings and' comparatively shallow-water 

 dredgings, containing few shells or stones, which 

 accounts for the comparative absence of many adherent 

 and deep-water forms which are normally found in 

 these waters. 



Society of Public Analysts, November 3. — Mr. A. 

 Chaston Chapman, president, in the chair. — VV. H. 

 Simmons : Formic acid as a reagent in essential oil 

 analysis. Continuing his work on the determination 

 of citronellol in geranium oils by formylation ("Year- 

 Book of Pharmacy, 1913 "), the author has examined 

 fifty further samples of Bourbon geranium oil, includ- 

 ing most oT the more important brands, and finds them 

 to contain 45 to 57 per cent, of citronellol, while 

 another ten samples of African geranium oil gave only 

 32 to 43 per cent., thus confirming the previous results. 

 Experiments on the formylation of various essential 

 oils and their alcoholic constituents show that tur- 

 pineol is almost completely decomposed by the process ; 

 geraniol and Hnalool are both converted into an appre- 

 ciable quantity of ester ; santalol is only very partially 

 decomposed, and citronellol, menthol, and the borneol 

 in rosemarv oil may be approximately estimated by the 

 process.— H. L. Smith : The melting point of salicylic 

 acid and a test for the presence of para-hydroxybenzoic 

 acid. The melting point of carefully purified salicylic 

 acid after drving over sulphuric acid is is^S° C- '^^^' 

 presence of small amounts of para-hydroxybenzoic acid 

 appreciablv lowers the melting point. The crystalline 

 forms of the acids are different, and the presence of 

 para-hydroxybenzoic acid may be detected by means 

 of the microscope.— E. Hinks : The jKirsistence of 

 hydrogen peroxide in milk. Experimental results 

 were given showing that unqualified statements as to 

 the length of time during which hydrogen peroxide will 

 persist in milk are of no value. The length of time 

 depends upon the age and condition of the milk. In 

 a case in which peroxide was added to a perfectly 

 fresh milk in the proportion of 02 per cent., it was 

 still present in estimable proportion after the lapse 



