May 24, 1877] 



NA TURE 



the observations of the Kimigsberg astronomer, the areographical 

 western longitude and the latitude of the centre of the disc, the 

 apparent diameter, the amount and position of the greatest 

 delect of illumination, and the areocentric angle between the 

 eanh and sun, all quantities for Greenwich alternate noon. 

 Vol. xxxii. of the "Memoirs of the Royal Astronomical 

 Society," contains the sketches of Lassell, Lockyer, and Rosse, 

 and this volume alone would be of considerable assistance to 

 the intending observer, as will appear from Mr. Marth's second 

 table. 



CHEMICAL NOTES 

 Cryst.\llisation under Galvanic Currents. — A recent 

 number of the Journal of the Russian Chemical and Physical 

 Society (vol. ix., fasc. 2) contains an interesting report, by M. 

 Shidlovsky, on observations he has made as to the microscopical 

 crystallisation of various metals under the influence of a galvanic 

 current. Placing on the object-glass of the microscope two fine 

 metallic plates, the edges of which are about a quarter millini. 

 distant, immersing them in a drop of water and passing a current 

 through, M. Shidlov>ky watched the growth of small ramified 

 threads of crystals of metal transported from the cathode to the 

 anode plate. The growth of these tree-like agglomerations 

 goes on very speedily ; their branches spread out to the anode 

 plate, vibrate on reaching it, and collapse, whilst another rami- 

 fied tree grows from the cathode spreading out to the anode ; this 

 goes on until the space between the plates is filled with a spongy 

 metallic mass. Each of the metals experimented on (lead, silver, 

 zinc, tin, copper, and iron) gives its own characteristic lamili- 

 cations, and if the two plates be of different metals the tree h.is 

 ramifications characteii^tic of the metal of which the anode plate 

 is made. Gold and platinum do not exhibit any appearance of 

 crystalline trees, nor does the crystallisation appear when the 

 anode is gold or platinum. Iron submitted to a continuous current 

 does not show a transport of crystals, but the phenomenon 

 appears immediately when the currents are originated by a 

 RuhmkorfTs coil or by a Iloltz's machine. Iron-powder sus- 

 pended in water undergoes a rapid motion under the influence of 

 a strong inductive current, forming threads which spread out 

 from the cathode to the anode plate. 



IsoDiBUTYLENE.— The same volume contains the second part 

 of the important paper by Prof. A. Butlerof on the polyme- 

 risation of hydrocarbures from the ethylene series : — On isodi- 

 butylene. 



On the Thermic Formation of Ozone. — M. Berthelot 

 has recently investigated this question by subjecting pure and dry 

 oxygen to the influence of the silent discharge, whilst passing 

 the gas into a ilask containing 500 c.c. solution of titered arse- 

 nious acid. At the end of thirty minutes, six to nine litres of 

 cxygen had passed through the flask, the temperature being 

 raised one-third of a degree ; then by passing the oxygen current 

 without the action of the discharge for an equal time, the ther- 

 mal data were rendered complete. The arsenious acid solution 

 was then treated with potassium permanganate, and redeter- 

 mined with a solution of oxalic acid. By this means the quan- 

 tity of arsenious acid oxidised, and consequently ozone absorbed, 

 was determined. The amount of oxygen absorbed was found 

 to be 30 '3 and Si'g milligrams, corresponding to 90' 9 and 

 1557 m.m. ozone, the heat set free being I lS"2 and 223 calories 

 respectively. Hence for one molecule the heat is equal to 

 -f 68-8 calories. Subtracting from this f-e heat formed in 

 the oxidation of a molecule of arsenious acid -I- 39'2 calories 

 (Favre and Thomsen), we have -i- 29'6 calories for the heat set 

 free in the condensation of one molecule ozone into oxygen, and 

 consequently - 296 in the reverse process. Ozone thettloie is 

 a body in which heat is absorljed in its formation, ils activity in 



combination being probably due to this heat being set free. This 

 is worthy of note when it is remembered that it is condensed 

 oxygen, condensation generally setting free heat. 



Chlorophyll in Conifer.e.— Conifenv are remarkable 

 amongst other plants for developing their chlorophyll even in 

 places which seem perfectly dark. In the Reports of the Nalur- 

 forschende Gesdhcha/t of Leipzig, Herr R. Sachsse pubUshes the 

 results of some investigations he made in order to ascertain 

 whether the chlorophyll formed under these circumstances is 

 quite identical with ordinary chlorophyll. He extracted the 

 chlorophyll from young Couifera:, which had germinated in the 

 dark, by boiling them in alcohol. He obtained a solution which 

 showed the ordinary chlorophyll spectrum ; all bands were in 

 the right position and showed the correct grades of intensity. 

 When the solution was concentrated the absorption at the end of 

 the spectrum was continuous, when more diluted the absorption 

 was resolved into the well-known three bands. The only 

 peculiarity in this spectrum, when compared with that of chloro- 

 phyll of ordinary origin, was the somewhat lesser intensity of 

 band V. According to Kraus's idea this would prove a pre- 

 dominance of cyanophyll over xanthophyll. The solution of 

 Conifera; chlorophyll very readily turns to modified chlorophyll. 



Chemistry of the Grai-e.— In several treatises lately 

 presented to the Royal Academy of Physical and Mathe- 

 matical Sciences of Naples, Prof. G. Licopoli gives an 

 account of some recent micro-chemicaV researches upon 

 oranges, lemons, and grapes. The latter are of special in- 

 terest, as Prof. Licopoli tried to determine the time and place 

 at which, in the gr'ape, the dil'ferer.t chemical substances which 

 arc contained in it (such as tartaric acid, chlorophyll, albumi- 

 noid matter, sugar, colouring matter, &c. ) firsi begin to form. 

 The conclusions which the author draws fi'om his labours are the 

 following : Tartaric acid and chlorophyll first show themselves in 

 the tissue of the pistils in course of formation. Oxalate of lime 

 next shows its presence in the sub-epidermic tissue in the form 

 of raphides, in the endocarpic epidermis in the shape of con- 

 glomerated crystals (dumb-bells ?), and in the kernels in raphides. 

 The albuminoid matter first appears spread over the whole of 

 the fruit, but ])redomlnates in the mesocarp. Colouring matter 

 results from the metamoi-phosis of chlorophyll, ils appearance 

 and diffusion showing the growth of the fruit, and the progr-ess the 

 chlorophyll has made at the time of its formation. The growth 

 of this colouring matter begins in the peripherical tissues, and 

 continues towards the central ones. Sugar is found in the 

 pericarp wherever there is tartaric acid present. Resinous 

 matter or wax appears first on the surface of the epicarpic 

 epidermis. Tannic acid is principally formed in the seed, and 

 particularly in the hard and friable part of the episperma ; the 

 fibro-vascular fascicles of the pericarp, however, also contain 

 this acid. 



NOTES 



We regret to hear that the state of health of M. Leverrier, 

 the distinguished director of the Paris Observatory, is causing 

 great anxiety to his friends. He has been entirely prostrated by 

 his enormous labours, which have been almost unceasing for the 

 last twenty years. 



M. Belgrand read, at the last sitting of the Council of the 

 Paris Observatory, a report on the necessity of extending tele- 

 graph warnings to Algeria, and taking advantage of the docu 

 ments collected by the Algerine Meteorological Service. The 

 necessary steps will be taken by M. Leverrier, and observations 

 extending from Marocco to Tunis, and from the Mediter- 

 ranean coasts to Laghouat and Biskra will be sent to and from 

 Paris to every Meteorological Oflice in conirectiou with the 

 meteorological system. At the same sitting M. I^everrier an- 



