June^, 1879] 



NATURE 



139 



pass on to the receiver, but without success. Also since the 

 vocal currents are alternately positive and negative, whereas the 

 induction ones are of one sign, he tried to avail himself of 

 the difference in discharging power of positive and negative 

 curre. ts, but without success. He then tried to take advantage 

 of the difference of period or duration of the currents, the induc- 

 tion currents being longer. He therefore tried to break up the 

 induction currents by interposing a rapidly revolving current 

 interrupter, and to make the sections of the musical note 

 obtained interfere with each other by means of an acoustic inter- 

 ference-tube, but practically failed in this also. He mentioned 

 these facts for the benefit of others who may be going over the 

 same ground. Mr. WoUaston pointed out that a perfect cure 

 for induction on underground wires consisted in twisting the 

 going and returning wire of the telephone circuit round each 

 other. — Mr. Wilson then read a paper on the divisibility of the 

 electric light by incandescence. By Joule's law the amount of 

 heat developed in a circuit of resistance, R, by the passage of a 

 current C = C^ R ; where R is the resistance of generator and 

 connections, r, added to the resistance of the light emitter 

 or incandescent wire, P. Therefore since by Ohm's law 



C — g we have — 

 R 



£^ E^ P 



From this equation the value of P may also be determined. 

 C'/* is the amount of heat developed in the incandescent wire. 

 He infers that the smaller the mass of the wire the higher 

 the temperature generated in it, therefore the mass of the wire 

 should be diminished until the fusing point of the metal is almost 

 attained. The question of divisibility resolves itself into our 

 being able to divide a single incandescent source into a number 

 of smaller ones giving the same total illumination. The author 

 concludes that this can be done by arranging the subdivided 

 sources in " multiple arc" or parallel circuits, provided the total 

 mass, length, and sectional area of the united sources be the 

 same as in the original single source. The objection that in- 

 creased radiation from the various sources would diminish the 

 first total of light and heat can be met by making the smaller 

 wires still smaller than is theoretically required so as to generate 

 more heat. The author regards the "voltaic arc" as probably falling 

 under the same law, the mass, however, being smaller in this case. 

 — Dr. Coffin then exhibited a Trouve polyscope, which consists of 

 a small, hand, incandescent platinum wire electric light, de- 

 signed for illuminating the more inaccessible cavities of the body 

 in surgical examinations. The current is supplied by a Plante 

 secondary battery, and the light is half inclosed in a small silver 

 reflector fitted with a convenient handle. The apparatus is 

 portable. Dr. Coffin found that it was open to several objec- 

 tions which he has remedied. Firstly, the heat generated made 

 the lamp so hot that it could not be held to the body for more 

 than a very short time. He overcame this by making the reflec- 

 tor of double silver plates, and circulating water between by means 

 of india-rubber pipes and a bulb which can be worked by the 

 patient himself, thus serving to distract his attention from the 

 operation. Secondly, the secondary battery exhausts itself in 

 twenty minutes, and the light therefore goes out, while from 

 twelve to twenty-four hours are required to recharge it. Dr. 

 Coffin has superseded it by a Leclanche battery of eight ele- 

 ments, made by Messrs. Coxetter and Sons, in which the carbon 

 pole is replaced by a copper plate faced with platinum, and no 

 porous diaphragm is employed. This gives a constant light for 

 hoiu-s. 



Anthropological Institute, May 13. — Prof. W. H. Flower, 

 LL.D., F.R.S., vice-president, in the chair. — Mr. Hyde Clarke 

 read a paper on the ethnology, mythology, and philology of 

 races of early culture : Babylonians, Etruscans, Egyptians, 

 Japanese, &c. Pursuing his former investigations, he now pro- 

 duced the comparative philology of Akkad, Coptic, Etruscan, 

 Lydian, Phrygian, Thracian, Carian, &c., copiously illustrated. 

 He showed the relationships of these among each other and with 

 the Ugro-Altaic languages, Georgian, the Himalayan, Naga, 

 Kolarian, and other Indian lainguages; Basque, the Pomo, 

 Hidatsa, and other American languages. All these he further 

 showed to be related to the numerous languages now spoken in 

 the more advanced highlands of Central and Western Africa, 

 as Mandingo, Bornu, Pulo, Timbuktu, Houssa, Ashantee, &c. 

 By reference to these larger stocks he conciliated the diver- 

 gences which appeared on the intercomparison of other lan- 



guages. Thus he illustrated many disputed points in the Akkad 

 grammar of M. Lenormant, and the alleged relations w ith the 

 Finnic. In treating the murology of the subject Mr. Clarke 

 referred to the marked differences between the Koord, Persian, 

 Armenian, and Eastern Aryans, and the Germanic and other 

 Western Ai7ans. His conclusion was that the so-called Eastern 

 Aryans are descendants of the pro-existing Turanians, having 

 merely acquired an Aryan language, and are to be assimilated 

 to the Georgian and other white Turanians, to the Assyrians, 

 and the Semites. To them he assigned the Etruscans and 

 Lydians. If the Aryans were to be regarded as descended from 

 High Asia, then the white Turanians may have descended from 

 High Africa, and they were the authors of the early culture. 

 When their power fell, although in Europe and Western Asia 

 they w ere replaced by the Aryan migrations, yet in other regions 

 they were extirpated by the black and brown (or red) natives. 

 Abyssinia, in conformity with its own legends, was to be 

 regarded as one of the last centres of this ancient empire, 

 and the Himyarite as one of the last invasions under 

 Semitic leaders. To the earlier epochs he assigned the Ame- 

 rican migrations and the mound-builders, when he considered 

 the Pomo as the possible language. Tracing a like conformity 

 in a primitive mythology as in philology, the author marked out 

 a Turar.ian epoch of Greece and of Rome, and explained the rela- 

 tion between Etruscan and Norse mythology by the existence of 

 a Turanian epoch of culture among the Germanic nations. — Mr. 

 A. L. Lewis communicated a paper entitled "Notes on some 

 Irish Antiquities." He observed that the country round Dublin, 

 while considered by Irish antiquaries to be comparatively desti- 

 tute of rude stone monuments, nevertheless contained as many 

 as some of those districts in England where they were most 

 plentiful. In the island of Howth, to the north of Dublin Bay, 

 are the remains of a dolmen called Finns Quoit, the cap-stone 

 of which measured no less than 15 feet long by 6 feet in thick- 

 ness. South of Dublin, in the ground of Mount Venus, seven 

 or eight miles from the city, is a stone 20 feet long by 3 feet 

 thick, leaning against one 8 feet high. At Killiney Station, on 

 the road to Bray, are remains known as the Druids Altar and 

 Druids Chair. The finest dolmen is in Carrick mines where five 

 upright stones support a capstone 17 feet long by 14 J inside, and 

 nearly 5 feet thick, forming a chamber 10 feet square. In con- 

 struction these remains resembled those known as the Trevethas 

 Stone in Cornwall. Of tumuli in Ireland the largest sepulchre 

 is probably that known in the New Grange tumulus situated 

 between Navan and Drogheda. Its peculiarities were noticed 

 by the author and contrasted with the remains at Gavr Inis, in 

 Brittany, and with the cuneiform chambers at Wayland Smith, at 

 WcUon, near Bath. Remains that have been observed in the 

 burial-ground of the Abbey Church of Slane, near Navan, were 

 next described, and the paper concluded with some interesting 

 observations on the well-known round towers of Ireland, and 

 with novel suggestions as to their origin and piu'pose. 



Royal Microscopical Society, May 14. — Dr. Beale, 

 F.R.S., president, in the chair. — This was the first meeting in 

 the Society's new room. — Papers were read by Mr. A. W. 

 Waters, F.G.S., on the occurrence of recent Heteropora; by Mr. 

 J. Davis, on a new species of Cothurnia ; and by Mr. Wenham, 

 on homogeneous immersion objectives. — The" exhibits included 

 photographs of blood-corpuscles, by Dr. Treadwell ; Rutley's 

 petrological microscope, by Mr. T. W. Watson ; and various 

 microtomes, by Mr. Crisp, &c. — Five new Fellows were elected, 

 and eight nominations read for the next meeting. — The second 

 scientific evening of the session, held on May 21, was very 

 numerously attended, many objects of novelty and interest being 

 exhibited, together with apparatus, amongst which were oil- 

 immersion objectives, by Zeiss and Powell and Lealand. 



Photographic Society, May 13. — J. Glaisher, F.R.S., in 

 the chair. — Mr. C. Bennett read a paper in reply to the discus- 

 sion on a previous paper read by him, on gelatine emulsions. 

 He stated that he still held the opinion that when an emulsion 

 was lightly salted with silver bromide, the particles were fine, 

 and remained so during long emulsification — as also the converse 

 with heavily salted specimens. With respect to the light 

 admitted for working his extremely sensitive emulsion, he found 

 that four square feet of four thicknesses of deep ruby glass were 

 preferable to one square foot of one thickness. — Mr. T. S. 

 Davis, F.C.S., read a paper on preparing small quantities of 

 gelatine emulsion, advocating the admixture of the silver and 

 bromide salts in powder to the gelatine solution instead of 

 previously dissolving them.— Mr. W. S. Bird read a paper on 



