Jan. lo, 1884] 



NA rURE 



255 



iodine, they did not by immersion in carbonic bisul,jhide at 

 6j° F., during thirty-six hours, yield any iodine, or impart any 

 c.ilour to that liquid ; the absorbed substance was not, therefore, 

 si'iiple iodine. A flat sheet of aluminium varnished on one side, 

 and then immersed in aqueous iodic acid, did not assume a 

 curved shape. A chemical analysis of the absorbed substance 

 has not yet been made. — Reduction of metallic solutions by 

 means of ga^es, &c., by Dr. G. Gore, F.R.S. This paper is a 

 record of a number of instance=; in which various solutions of 

 metals were reduced lo the metallic state by contact with gases, 

 and different organic compounds. The solutions chiefly em- 

 ployed were those of palladium, iridium, platinum, gold, silver, 

 and mercury, and less frequently those of copper, lead, iron, 

 manganese, chromium, vanadium, and telhtrium. The ga=es 

 used wfre hydrogen, carbonic oxide, coal ga--, and crude acety- 

 lene. The organic compounds included both liquid and solid 

 substances ; the liquids were amylene, petroleum, benzene, 

 Persian naptha, xylol, toluol, carbolic acid, " petroleum ether," 

 mesilylene, and liquid chloride of carbon, and the solids were 

 jjarafiin, ozokerite, naphthalene, anthnicene, chrysene, elaterite, 

 sojid chloride of carbon, &c. By contact with gases the metals 

 were generally reduced in the form of films upon the surface of 

 the liquids, as well as in that of precipitated powder ; some of 

 the films produced, both by the contact of gases and by that of 

 non-miscible liquids, were remarkably beautiful, and of a sur- 

 prising degree of thinness. Amongst the most conspicuous 

 instances of reduction were the following; : — a solution of pallaiiic 

 chloride was rapidly reduced by carbonic oxide, hydrogen, coil 

 gas, and amylene. One of terchloride of gold was quickly 

 decomposed and reduced by coal gas, carbolic acid, and amy- 

 lene. The mot beautiful films were those produced by a 

 s jlution of terchloride of gold, with coal gas or with amylen-. 

 Solutions of chloride of palladium were usually more rapidly 

 decomposed than th'ise of chloride of gold. The films of metal 

 thus produced might prove of service in some optical and other 

 physical invetigati ins. It is worthy of consideration also by 

 geologists, whether the reduction of metals to the native sta'e in 

 the interior of the earth may not in some cases have been effected 

 by contact of their solutions with liquid or gaseous hydrocarbons 

 derived from coal and other mineral substances of organic origin. 



Paris 

 Academy of Sciences, December 31, 1883. — M. Blanchard, 

 president, in the chair. — Action of heat on aldol and paraldol, 

 by M. Ad. Wurtz. — On a white rainbow (Ulloa Circle) observed 

 at Courtenay (Loiret) on the morning of November 28, by M. 

 A. Cornu. This extremely rare phenomenon occurred under 

 atmospheric conditions closely analogous to those described by 

 Uravais in the Jourit. de I' Ecole Polytech., xxx. p. 97. The 

 radius appears to have been much shorter than that of the 

 ordinary rainbow. — Mi.-sion to Cape Horn : Summary report on 

 the researches made in natural history and anthropology by the 

 Romattche, by Dr. Hahn. In the north-eastern islands of Tierra 

 del Fuego acquaintance was made with the Ua people, who 

 present several remarkable peculiarities. Although living on 

 frienely terms and even intermarrying with the more southern 

 V.ahgans, they seem to be related in stock and speech rather to 

 the continental Patagonians. They appear even to exceed them 

 in stature, and thus to rank as the vei-y tallest race on the globe. 



— Note on the tidal curves registered between November, 1SS2, 

 and September, 18S3, by the maregraph at Orange Bay, Cape 

 Horn. — Observations of the Pons-Brooks comet at the Obser- 

 vatory of Nice (Gautier-Eichens equatorial), by M. Perrotin. 



— Spectroscopic .study of the Pons Brooks comet made with the 

 reflector of 0-50 m. at the Observ.atory of Algiers, by M. Ch. 

 Trepied. The following results were obtained : — 



Comet Flame of 



o alcohol 



Reading for line D 1318 ... — 



First green line (less refrangible) ... 13'92 ... I4'C9 



Second green line I5-I2 ... 15-20 



Blue line 1676 ... 1704 



showing that in its visible parts the spectnim of the comet is 

 identical with that of a flame of alcohol. — On the multipliers of 

 the linear diflerential equati ms, by M. Ilalphen. — On a means 

 of determining the factor of integrability, by M. W. Maximo- 

 vi-ch. — On the generation of surfaces, by MM. J. S. and M. N. 

 Vanecek. — Reply to M. Larroque's observations on the experi- 

 ments recently made in connection w ith the study of earth cur- 

 rents, by M. E. E. Elavier.— On the temperature obtainable by 



means of boiling oiygen, and on the solidification of nitrogen, 

 by M. S. Wroblewski. Reserving a description of his process, 

 the author .announces as a first result an approximate temperature 

 of -186° C. When subjected to this intense degree of cold, 

 nitrogen became silidified, falling like snow in crystals of a re- 

 markable size. — On the maximum of silubility of soda, by M. 

 E. P.mchon. — On an incomplete oxygenised monamine (oxallyl- 

 diethylcnine, by M. E. Rob ml. — On the fluorides of sodium, by 

 M. Guntz. — Researches on ptomaines and analogous compounds, 

 by M. A. Gabriel Pouchet. — Action of copper on the health of 

 persons engaged in the copper industries ; histoiy of a workshop 

 and of a village, by M\f. A. Houles and de Pietra-Santa. The 

 history of this village (Tarn, Durfort) extends over a period of 

 a hundred years, and tends to shiw that c:)ppersmiths (forgers, 

 braziers, ttc.) are on the whole as l^ng-lived if mt nnre so than 

 the agricultural population of the same distr cl. — On the anatomy 

 of a human enbryo in the fourth week, by M. H. Fol. — On a 

 new species of the genus Megaptera (Mcgtptfra inciica) from the 

 Bay of Bassora, Persian Gulf, by M. P. Gervais. — On a rare 

 siiecies of Dolphin (On-a gladiator, Grav = Ddpkinus orca. 

 Fab.) recently captured oft" Trepjrt. Seine-Inferieure, by M. H. 

 Gadeau de Nerville. — On the vitelline nucleus of the Araneidte, 

 by M. A. Sabatier. — New ophidological discoveries, by M. 

 Lichtenstein.— On a phenomenon accompanying the red after- 

 glow of the sunsets of December 26 and 27, 1883, at Tortosa 

 (Spain), by M. Jo'e J. Landerer. — Terrestrial physics: the 

 Krakatoa catastrophe ; velocity of the earthquake wave-, by M. 

 Erington de la Croix. From observations made in Ceylon, 

 Mauritius, and other places, the earthquake wave of August 27, 

 1883, seems to have been propagated acrow the Indian Ocemi 

 at the prodigious velocity of about 550 m. per second, or 2000 

 km. per hour. 



Berlin 



Physiological Society, December 7, 1883. — Prof. Waldeyer 

 brought before the Society the results of investigations pursued 

 by Herr Koganei in his Institute into the histogeny of the retina. 

 It was known that the retina was a development of a vesicular 

 projecting flap of the brain {Hen' irstiil piing des Ge/iirns), and 

 that this membrane of the eye consisted in its early stages 

 of fusiform cells. Whether there were other cells besides con- 

 tained in it, how they were developed, and how the different 

 constituents of the developed retina «ere diflferentiated, were, on 

 the other hand, all matters of debate. Herr Koganei had now 

 found that in the earliest stages this membrane of the eye 

 was composed of two series of cells, one of fusiform cells on the 

 distal side of the membrane, the other of round cells supplied 

 with caryokinetic nuclei on the proximal side. The fusiform 

 cells were called "fundamental," the round cells "prolific," 

 these latter alone multiplying, as they did, by scission, and fur- 

 nishing the whole material for building up the retina. The 

 increase in retina elements proceeded therefore altogether from 

 the proximal side, whence the newly-produced cells intercalated 

 themselves into the layer of fusiform cells, all which phenomena 

 entirely corresponded with those of the brain, it likewise growing 

 only by multiplication of cells on the ventricular side. The 

 differentiation of the fusiform cells into separate retina layers 

 began after the ocular chamber was formed by the invagination 

 of its most anterior part which becomes transformed into a 

 double saucer shaped form, or rather it was only the inner- 

 most saucer which became the retina, while the outer saucer 

 was converted into the pigment layer, the cells of which were 

 filled w-ith pigment. The difterentiation followed a law of 

 quite universal application. In every case it began on the 

 distal side, which, on the invagination of the ocular cham- 

 ber, became the inner side, and advanced gradually to the 

 outer side of the retina. It began consequently with the 

 oldot fusiform cells, and passed gradually over to the later- 

 formed fundamental cells. As analogous to this was next 

 recognised the membrana limitans interna, with the supporting 

 fibres of Midler. These formed themselves out of the innermost 

 layer of the oldest fusiform cells, which ranged themselves 

 strongly out in a longitudinal direction, and became flattened on 

 their inner end. The basal lamin.r; [Ftusplatten) of these cells 

 impinging on each other formed the membrana limitans. Then 

 the layer of ganglion cells appeared, and, almost simul- 

 taneously, the layer of optic fibres intervening between the 

 layer of ganglion cells and the membrana limitans. The 

 mode by which the ganglion cells were developed was 

 through the rouniing of the fusiform cells and their emission of 

 offshoots. With regard to the layer of nerve-fibres it was a^ctr- 



