Aprils 1885] 



A' A TURE 



Linnean Society, March 19. — Sir John Lubbock, Hart., 



chair. — Dr. J. G and Mr. Chas. T. 



Fellows of the Society. — Dr. G. J. Romanes 



exhibited two human crania from South Africa ; one was that of 



an aboriginal I n [Cruis River, C; ict, Gudts- 



. obtained through Dr. .Stroud. — Mr. J. G. Baker drew 



attention lo a specimen of a supposed hybrid between the two 



genera A he ai . and grown in the Glasgow Botanic 



Gardens. He also showed a curious new fern. Poly 



ictylon, Hance, discovered by Mr. W. 

 Hancock, F.L.S., in the Island of Formosa. — A paper was 

 "llection of Miss Gatty, by 

 Prof. Allman. Thirtj ributed among twelve 



w. Among these the plumularian 

 genus, Podocladium, is very remarkable, not only by the posses- 

 iii ■■■, ible nematophore, in accordance with 

 the Challenger collection, it holds a 

 ton intermediate between the typical Eleutheroplean and 

 by the fact that every hydrocladium 

 is supported on a cylindrical jointed peduncle. Among other re- 

 markable and signific ne to which the author gives the 

 nameof77«« pha. Inthisare found combined on the 

 same hydrophj an three morphological types, which, 

 if occurring would be justly regarded as representing 

 three genera, T/iuiai vphus, and Sertularia. Not- 

 withstanding this singular combination of forms, the author does 

 not believe that the characters of the specimen justifies the con- 

 struction of a new genus ; and he regards the generic position of 

 the hydroid as determined by that one of the three forms which 

 decidedly prevailed in it. Thuiaria heteromorpha thus 

 in a very marked way the indefiniteness of the boundaries 

 ,n different zoological groups, and calls to mind a phe- 

 nomena known to occur among plants, as in certain epiphytical 

 ids, in which the same stem has been observed to carry 

 flowers referable to several generic types. — Then followed a 

 ■ by Capt. William Armit, F.L.S., viz. on plants met with 

 by him on M I -':. O'Neill, and Margaret I 

 South Eastern New Guinea, and in which a list of over 130 

 species are given. 



Physical Society, March 14. — Prof. Guthrie, President, in 

 the chair. — Capt. Abney read .1 paper upon recent researches 

 on radiation. In general a hot body loses heat in three ways : 

 by conduction, by convectioi liation. In the case of 



the carbon filament of an incandescent lamp the loss 01 heat by 

 conduction is insignificant, and a series of experiments has been 

 to determine the amount of radiation — that is, the energy 

 expended as radiant heat for every unit of electrical energy 

 tided in the lamp. Mr. Crookes has investigated the sub- 

 ject of radiation in high vacua, the cooling bodies being thermo- 

 meter bulbs, and has come to the conclusion that, at pressures 

 ' 1 millionth of an atmosphere, the 

 radiation varii lean molecular free path. In the 



author's experiments incan of thin glass were 



radiation being measured by 

 a thermopile. It was found that, from 40 milliomhs to 10 mil- 

 lionths of an atmosphere the radiation increases uniformly with 

 decreasi . but that beyond this point it becomes 



nearly constant. A more important question is to determine the 

 amount of radiation for any particular ray under the above con- 

 dition-, ing a small thermopile in the 

 different parts of th« Hotting the results with walls 

 as abscissa', and radii ites, the curves for each kind 

 of ray are found to be very accurately hyperbolas with vertical 

 This result gives a method for rendering identical the 

 v of the light emitted by two lamps. We have 01 

 find the icular kind of light for 

 11 1, id then, by examining the curve corresponding to 

 that ray for the other lamp, find for what number of watts the 

 radiation is the same.— Pro] ling read a papei on 

 characteristic curves nl lamps. The author has 

 of statistics connecting the life, resistance, 

 efficiency, and potential difference of incandescent lamps, and 

 nuined them with a view of showing the mutual relations 

 of these variables by empirical equations. A curve showing the 

 relation of any one of them to any other is called a characteristic 

 curve of the lamp. Among the various results arrived at was 

 nlirmation of the law, announced by Profs. Ayrton and 

 Pa iy at the last meeting of the Society, that for a certain class 

 of lamps the potential difference, minus a constant, varies as the 

 cube-root of the efficiency, the latter quantity being measured 



by candles per horse-power. The constant, which, in the lamps 

 examined, is about 287, is nearly the potential difference at 

 which the lamp begins to emit light ; hence the law may be put 

 into this form : The effective potential difference varies as the 

 cube root of the efficiency. Using the results obtained, the 

 author then solved the problem of determining the conditions 

 for a minimum cost per candle, anil obtained a result closely 

 agreeing with that communicated at the last meeting by Profs. 

 Ayrton and Perry. In answer to Lord Kayleigh, Dr. Fleming 

 stated that he had not calculated the increase of cost due to a 

 variation from the most favourable conditions ; it had been 

 shown, however, by Messrs. Ayrton and Perry that the increase 

 of cost due to a variation of potential difference amounting to 

 3 or 4 per cent, upon either side of the value corresponding to 

 least cost was very small. — Mr. C. Cleminshaw described some 

 further experiments on spectrum analysis. These consisted of 

 methods of obtaining the inversion of the sodium line in the spec- 

 trum of the limelight. The first consisted in concentrating the 

 rays from the slit by a lens, just beyond the focus of which is a 

 spoon in which sodium is ignited by a Bunsen flame. In the 

 second method the burner and sodium are introduced between 

 the lime and the slit, and carbonic acid is introduced into the 

 flame. The result in either case is to cause the inversion of the 

 D line. Prof. Guthrie, alluding lo the pale blue flame produced 

 by common salt in a coal fire, suggested that there might be 

 more than a mere mechanical action produced by the carbonic 

 acid. Mr. Cleminshaw, however, believed that the action was 

 purely mechanical. — An abstract of a communication by Dr. 

 John Hopkinson on Sir W. Thomson's quadrant electrometer 

 was read by the Secretary. According to Maxwell, the deflec- 

 tion produced by a given difference of potential between the 

 quadrants is given by the formula — 



d = A(A-£)(c-djL*} 



where A and B are the potentials of the quadrants, and C that 

 of the needle. Dr. Hopkinson finds, however, that the constant 



A should be - , the quantity k being due to and depend- 



ing on the unsymmetrical position of the needle with respect to 

 the quadrants. 



Zoological Society, March 17. — Prof. W. H. Flower, 

 LL.D., V.P.R.S., President, in the chair. — Mr. Sclater exhi- 

 bited and made remarks on a duck shot on Lord Bolton's estate 

 in Yorkshire which appeared to be a singular variety of the 

 Scaup (Fuligula marild). — Mr. W. B. tegetmeier, F.Z.S., 

 exhibited and made remarks on a pair of abnormal deer's antlers 

 obtained in India. — Dr. F. H. H. Guillemard read a paper on 

 the ornithology of the Sulu Archipelago, showing that the arm's 

 of that group is purely Philippine, and that the line of separation 

 between the latter archipelago and Borneo lies between the 

 islands of Sibutu and Tawi-tawi. Dr. Guillemard added fifty 

 to the list of birds hitherto known from Sulu, two of 

 which were new to science. — A communication was read from 

 Mr. T. Kirsch, of the Royal Zoological Museum, Dresden, con- 

 taining descriptions of some new butterflies obtained by the col- 

 lectors of Mr. Riedel in Timor-I aut. — A communication was 

 read from Prof. W. Nation, C.M.Z.S., containing some notes 

 on the Peruvian cliff-swallow {Petrochelidon ruficollis). — A com- 

 munication was read from the Rev. H. S. Gorham containing a 

 revision of the Phytophagous Coleoptera of the Japanese fauna, 

 of the sub-families Cassidhnr and Hisphia. — A communication 

 was read from Lieut.-Col. C. Swinhoe, F.Z.S., being the second 

 of his series of papers on the Lepidoptera of Bombay and the 

 Deccan. The present paper treated of the first portion of the 

 Heterocera. — Dr. Hans Gadow, C.M.Z.S., gave an account of 

 the anatomical differences observed during an examination of 

 examples of the three species of rhea [A'/t. americana, macro- 

 rhyncha, and darwini). 



Chemical Society, March 19.— Dr. W. H. Perkin. F.R.S., 

 it, in the chair. — The following papers were read : — On 

 the presence of choline on hops, by Dr. Griess, F. R. S., and 

 Dr. G. II. Harrow.— Fluorene, Part III., by Dr. W. R. 

 Hodgkinson. — Combustion in dried gases, by H. Brereton 

 Baker, B.A. 



Entomological Society, March 4. — The President in the 

 chair. — Four new members were elected. — Mr. T. R. Billups 

 exhibited specimens of Ceraleptus lividus, Stein, from Chobham. 

 — Rev. W. W. Fowler exhibited the unique specimen of Cerylon 



