Vienna Academy Research Articles

The Physical Nature of the Sun 1

THE question whether all points of the sun are alike, in reference to the emission of light and heat, is not yet decided. As to the distribution of heat on the sun, many investigations have already been made with a view to answering this important question. Nervander seems to have been the first to discover (from temperature observations at Paris and Innsbruck) a temperature inequality of about ½° R., which has moreover the period of the sun's rotation (27.25 days). Simultaneously, Dr. Buys Ballot made a similar inquiry in Utrecht Proceeding on the supposition that a kind of heat pole exists in the sun, and that accordingly the rotation of the sun must appear from long series of temperature determinations, he got from observations of temperature at Harlem, Zwanenburg, and Danzig, a period of 27.682 days. Since this result differs so much from that of Nervander, Buys Ballot subjected the calculations of Nervander to a thorough scrutiny, from which he concluded that that observer had “not only taken the moon for the sun, but had also mistaken the former.” In his memoir Buys Ballot further showed, that to the colder side of the sun, which was presented to us on 1st January, 1846, a temperature corresponded that was, on an average, about 0.7° lower than that of the warmer side, which was presented to us on 15th January of that year. Carlini and D'Arrest got nearly the same result as Nervander. Airy, on the other hand, was unable to decide from the Greenwich observations. Since by the distinguished researches of Hornstein, Director of the observatory at Prague, and of Broun, it has been proved that the time of the sun's rotation may be deduced from variations of magnetic and barometric phenomena more accurately and from a short series (one year) of observations, and since both the period of Nervander and that of Ballot differ so much from Spoerer's and Carrington's rotation period, I submitted the Prague temperature-observations for 1876 to a closer examination, expecting a much shorter period from these than Hornstein got from magnetic and barometric obserations, as I supposed that it would correspond to the rotation, deduced from spot observations, of the thermal equator of the sun, which, it is known, does not coincide with the true equator. I worked the observations therefore by the method given by Hornstein in the Sitzungsberichte of the Vienna Academy (Bd. 67), as it is peculiarly suited for such researches. I here communicate the final result. The most probable value obtained for T was 25′56days. According to Carrington's observations, the position of the thermal equator of the sun on the foregoing sypposition would have the latitude to to 20°, according to Spoerer's observations, the latitude 13° to 40°. As recent researches seem to show that the influence of variation of the forces of the sun is reflected in the variations of meteorological phenomena, I further investigated the wind components of the year 1870, in their relation to the rotation-time of the sun. For the east-west-components I found a period of 26-71 days. Whether from this result may be concluded a correspondence between prevalent winds in the sun, such as Spoerer has deduced from his spot-observations, will have to be decided by closer investigation.

On Heliotropism in Plants

THE heliotropic phenomena in plants form the subject of a monograph by Herr Wiesner, the first part of which has been recently communicated to the Vienna Academy. The following outline from the Anzeiger of the Academy will give an idea of some of the fruits of the author's researches on this important subject.

Liquids having a Specific Heat Higher than Water

IN NATURE, vol. xvii. p. 252, it is stated: Hitherto water has been regarded as possessing a greater specific heat than any other body excepting hydrogen. E. Lecker has shown to the Vienna Academy that mixtures of methylic alcohol and water have a specific heat higher than that of water, and accordingly take the second place, c Watts's Diet., 2nd Supplement, 475). Moreover, we especially mentioned “that our experiments furnished the first example of a liquid having a specific heat higher than that of water”. Since 1869 Dr. Dupre has estimated (Proc. Roy. Soc., xx. 336) the specific heats of mixtures of methylic alcohol and water without finding any such mixture to possess a specific heat above that of water.

Science in Germany

(From a German Correspondent) HERR v. OBERMAYER has recently communicated a memoir to the Vienna Academy on the relation of the coefficient of internal friction of gases to the temperature. If we accept for the coefficients of friction μ at t°, the formula—

Scientific Serials

Der Naturforscher, May.—This serial, containing little that is original, furnishes a weekly supply of well-selected and adapted matter froth various sources. In the present number attention may be called to an academical address delivered by Herr Sirengat Giesseh, onthe “circle-course” of substances in nature, treating chiefly of geological phenomena; to an account of Herr Janettas's recent careful researches on the conduction of heat in crystals (some 44 mineral species having been examined); to atlseoretical investigation by Herr Handl (Vienna Academy) of the conditions of saturated and supersaturated solutions, and to several papers of meteorological experimnt: on moisture in forests and in the open, On the temperature of lain, and on the velocity of winds as measured on various heights on Antwerp Cathedral.—Some observations of M. Du Breuil on the partial decortication of horse-chestnuts, are worthy of notice. He found about twenty of these trees in the park at Compiègne, the bark of which had been eaten off twenty-four years previously, by rabbits, to a height of 30 or 4o centimetres. From several experiments he concluded that the chestnuts could live thus long without conmunication with the soil, and that the elements necessary to their growth were obtained partly from the atmosphere, partly through endosmose from the woody tissue formed before decortication.—Among several French Academy papers are those by M. Jamin on the laws of the normal magnet, and M. Faye on circulation of hydrogen in tlse sun.—English and American science is also represented.—A curious fact is stated in the “Kleinere Mitubeilungen”: Herr Eimerhas recently found, on a precipitous rock near the island of Capri, a stew species of lizard. It is blue all over, with dark spots on the back; while the lizards in Capri are of a bright green, with only a little blue at the extremities, Now the rock (which is frequented by birds of prey) has little or no vegetation, and its natural colour is a bluish grey, or dark blue in the shaded parts. The lizard, when at rest, can hardly be detected by sight, its colour is so like that of the rock. Herr Eimer finds indications that the rock was once connected with the land, and supposes green lizards to have gone over and been gradually transformed to blue, through natural selection.

Untersuchungen über die Mikroskopische Zusammensetzung und Structur der Basalt-Gesteine Mikromineralogische Mittheilungen Beiträge zur Petrographie der plutonischen Gesteine Sur les Crystallites, études crystallogeniques Kritische Mikroskopisch-mineralogische Studien Mikroskopische Unterscheidung der Mineralien aus der Augit, Amphibole und Biotit-gruppe

II. AMONG the Continental petrographers who have led the way in the recent reform and extension of this branch of science, none can claim a more prominent place than Dr. Zirkel. Although still a young man, he has held professorships successively at Lemberg and at Kiel, and we rejoice to hear from him that he has been selected to succeed the venerable Dr. Naumann at Leipzig. He is the author of many excellent mineralogical and petro-graphical papers, and of the best text-book of petrography which has yet been published. Especially has he distinguished himself by the zeal with which he has followed out the ideas first broadly sketched by Mr. Sorby, and has shown how absolutely indispensable is the application of the microscope to the study of the composition and history of rocks. His researches, while extending over the length and breadth of Germany, have not been confined to the Continent, but have been carried with characteristic enthusiasm even as far as the peaks of Arran, and the cliffs and glens of our north-western isles. Untersuchungen über die Mikroskopische Zusammensetzung und Structur der Basalt-Gesteine. Von Dr. F. Zirkel. (Bonn, 1870.) Mikromineralogische Mittheilungen. Von Dr. F. Zirkel. Pp. 801. (Neuses Jahrbuch für, Mineralogie, 1870.) Beiträge zur Petrographie der plutonischen Gesteine. Von Justus Roth. (Reprinted from the Transactions of the Royal Academy of Sciences of Berlin.) Sur les Crystallites, études crystallogeniques. Par H. Vogelsang. (Archives Néerlandaises, 1870.) Kritische Mikroskopisch-mineralogische Studien. Von H. Fischer. (Freiburg.) Mikroskopische Unterscheidung der Mineralien aus der Augit, Amphibole und Biotit-gruppe. Von G. Tschermak. (Proceedings of the Vienna Academy of Sciences, 1869.)

I. On the phenomena of light, heat, and sound accompanying the fall of meteorites

A particular incident caused me to return to some portions of my earlier studies in regard to meteors and meteorites. It was the fall of a meteorite at Kakowa on the 19th of May 1858 that first induced me to bestow some more attention on this department of physical science. A report on the subject I laid before our Imperial Academy of Vienna on the 7th of January, 1859. On the same day also I gave the first list of the meteorites forming the meteorite collection in our Imperial Mineralogical Museum. A series of reports on meteorites followed, as well as a number of catalogues of meteorites, in accordance with the growing riches of the collection, embracing from 137 to 236 numbers of localities preserved up to the date of July 1, 1867.

I. On the frequent occurrence of vegetable parasites in the hard structures of animals

As far as I am aware, Quekett has been the first to point out that vegetable parasites, viz. Confervæ , occur frequently in the skeleton of Corals (Lectures on Histology, vol. ii. p. 153. fig. 78. and p. 276); but although he mentions in the same place that the tubuli described by Carpenter in the shells of Bivalves have also a great resemblance with Confervæ , he did not venture any further step, and he adheres to the view of Carpenter, who regards them as a typical structure. Some years later, Rose ( “On Parasitic Borings in Fossil Fish-Scales,” Transactions of the Microscopical Society of London, vol. x. p. 7, 1855) discovered a peculiar tubular structure in fossil fish-scales, which he regarded as being occasioned by parasites, and possibly by Infusoria, but he was not able to give any good proof of this hypothesis. The same must be said of E. Claparède (Müll. Archiv, 1857, p. 119), who found similar canals in the test of Neritina fluviatilis , and showed that they do not really belong to the shell, without being happier in determining the nature of the parasite, only suggesting that it might possibly be a sponge. Such was the state of things, when Prof. Wedl of Vienna and I, independently of each other, took up the question. The observations of Wedl, which concern only the parasites of the shells of Bivalves and Gasteropods, were communicated to the Vienna Academy on the 14th of October, 1858, and are therefore previous to my own, which were presented to our Würzburg Society on the 14th of May, 1859; but I received Wedl’s memoir only on the 16th of May, and may therefore say that my observations, which are also extended over many more groups of animals, were quite independent of those of the Austrian microscopist. This being the case, it may be regarded as a good proof of the correctness of our observations and the truth of our conclusions, that we agree in the principal facts, there being only this discrepancy between us, that Wedl calls the parasites Confervæ , whilst I regard them as Unicellular Fungi . The botanists will decide this question better than we; only I beg leave to say, that all the numerous parasites observed by myself were unicellular , and that the sporangia were quite of the same kind as those of unicellular fungi. I may further add, that the frequent anastomoses of the parasitic tubes remind one of the anastomoses observed in the mycelium of some unicellular fungi, whereas such connexions have not yet, so far as I know, been observed amongst the Confervæ .