354 



NATURE 



[August io, 1893 



and recently issued by the Government of Madras. It includes 

 an account of corundum deposits in the Madras Presidency, and 

 one on the phosphatic nodules of the Trichinopoly district. Dr. 

 Warth says that the entire area covered by these nodules is 

 about ten square miles, and that about four thousand tons of 

 nodules are lying more or less loosely on the surface. 



The fourth volume of the Bulletin of the American Museum 

 of Natural History contains a large number of important papers, 

 among which we note one by Prof. H. F. Osborn and Mr. J. 

 L. Wortman on " Fossil Mammals of the Wahsatch and Wind 

 River Beds," and another by Mr. J. A. Allen on "The Geo- 

 graphical Distribution of North American Mammals." Mr. 

 F. M. Chapman contributes an article on birds and mammals 

 observed near Trinidad, Cuba, with some remarks upon the 

 origin of West Indian bird life, and Mr. W. Beutenmiiller gives 

 several papers on Lepidoptera. 



The proceedings of the Bristol Naturalists Society for 1892 

 contains several interesting papers. Among others of general 

 scientific interest we note a paper describing the fish-remains of 

 the lower carboniferous rocks of the Bristol district, by Mr. A. 

 J. Heath and Prof. C. Lloyd Morgan. Mr. Claud Druit gives 

 an account of the Green Woodpecker, and Mr. H. J. Char- 

 bonnier contributes some notes on the habits of the larvae of 

 Gracillaria Syringella. Dr. J. A. Norton writes on the colora- 

 tion of cuckoo's eggs. We regret to learn from the report that 

 this once flourishing society is declining in numbers. 



Messrs. Newton and Co., Fleet Street, have brought out 

 a new kind of gyroscope top, which should be of interest to 

 students of the dynamics of rotation. In it a shallow bell with 

 heavy rim takes the place of the usual disc. At the inner apex 

 is a point which rests on a steel cup in the top of a firm up- 

 right. By means of this support, freedom of motion in different 

 planes is obtained without the use of gimbals. The top can be 

 set spinning by twirling it between the fingers, and, owing to 

 the fine workmanship, it will keep in motion for a considerable 

 time. If any geometrical figure made by bending a piece of 

 stout wire is fixed above the point of support, the upper end of 

 the axis of the top follows the form so long as rotation is ob- 

 tained, running continuously round it in a very remarkable 

 manner. If the top were intended for a gyroscope, its axis 

 should always remain parallel to itself unless guided in the way 

 described. But this is not the case. The axis slowly gyrates 

 and wobbles as it does so. These motions certainly imitate 

 precession and nutation, but the mode of exemplification may 

 lead beginners to a misconception. There is a possibility of 

 being led away with the idea that the earih's axis changes its 

 direction by itself, whereas it cannot be too strongly insisted 

 upon that the effect is produced by external attraction. 



An important communication upon the production of ozone 

 at high temperatures is contributed by Dr. Brunck, of Freiberg 

 to the current number of the Berichte. The very title of the 

 memoir is contrary to all our usually accepted ideas concerning 

 the stability of ozone, but Dr. Brunck advances experimental 

 evidence to show that polymeric oxygen is capable of formation 

 and of subsequent existence for a short time even at tempera- 

 tures of considerable elevation. It is quite true, as Andrews 

 and Tait long ago pointed out, that at 300° ozone is converted 

 into ordinary oxygen, indeed. Prof. Andrews gave 237° as the 

 temperature of dissociation ; but Dr. Brunck shows that the 

 change is by no means instantaneous, and that if the gas is only 

 allowed to remain for a short period of time in the heated vessel, 

 a considerable proportion escapes decomposition. A quantity 

 of oxygen was partially ozonised in the ordinary manner by 

 means of a Siemens tube, and the gases, which contained about 

 five per cent, of ozone, were led very slowly through a com- 

 bustion tube heated to 350° in an air bath ; the issuing gas was 



NO. I 24 I, VOL. 48] 



found to still contain twenty per cent, of the original quantity of 

 ozone present. Filling the combustion tube with fragments of 

 porcelain did not appear to materially diminish the quantity of 

 ozone escaping dissociation. Dr. Brunck then proceeds to de- 

 scribe several high temperature reactions in which oxygen is 

 liberated to a not inconsiderable extent in the condensed form 

 of ozone. Schonbein some years ago made the remark that the 

 oxygen evolved upon heating certain metallic oxides and per- 

 oxides appeared to contain ozone, inasmuch as it rapidly liber- 

 ated iodine from potassium iodide. This statement, which ap- 

 pears to have been overlooked or mistrusted, is completely 

 confirmed by Dr. Brunck, who shows that oxide of silver evolves 

 as much as five per cent, of its oxygen in the form of ozone. 



The most interesting portion of Dr. Brunck's paper, however^ 

 is that in which he adduces experimental evidence that th 

 strongly odourous gas hitherto considered to be chlorine, whic 

 is usually admixed to a slight extent with the oxygen prepare 

 by heating a mixture of potassium chlorate and manganese dii 

 oxide, is in reality ozone. It is certainly singular that Marignaq 

 on attempting to determine the amount of such admixed so 

 called chlorine in a strongly odourous specimen of the ga?, oalj 

 obtained three milligrams of silver chloride from fifty granj;; of 

 potassium chlorate. Dr. Brunck now shows that an aqueous 

 extract of the residue in the flask, after heating the mixture of 

 potassium chlorate and manganese dioxide, always reacts neu:ral 

 to litmus ; whereas if free chlorine were evolved the residue 

 must of necessity be alkaline. Moreover, even after repeated 

 washing of the gas with concentrated solutions of caustic potash, 

 sufficient to remove any free chlorine, the gas still maintains its 

 strong odour, at once forms blue iodide of starch with a starch 

 and potassium iodide paper, and bleaches a moistened litmus 

 paper. Further, upon leading the gas through alcohol, aldehyde 

 is produced, an oxidation which free oxygen alone is incapable 

 of bringing about. The active properties and the odour are, 

 however, completely lost after passage of the gas over a layer of 

 manganese dioxide at the ordinary temperature, as would be the 

 case if ozone were the energetic gas present in the oxygen. The 

 above experiments concerning the comparative stability of ozDne 

 for a short time at high temperatures quite account for the forma- 

 tion of ozone when a mixture of potassium chlorate and man- 

 ganese dioxide is heated. Dr. Brunck finally shows that the 

 amount of ozone produced is considerably augmented by remov- 

 ing the escaping gases mdre rapidly from the heated mixture by 

 means of a current of air or other inert gas. Pure potassium 

 chlorate appears to yield no ozone upon heating, but a mere 

 trace of impurity, such as potassium chloride or silica, causes 

 more or less of the oxygen to be evolved in the form of ozone. 

 Hence commercial chlorate always yields a small proportion of 

 ozone. 



Notes from the Marine Biological Station, Plymouth. — The 

 floating fauna has now begun to assume its distinctive autumn 

 characters. During the past week there were taken, in addi- 

 tion to the larvjE of Chtztopterus , Amphioxus larvae, the Tornaria 

 larva of Balanoglossus, numbers of Plutei and some Bipinnaria, 

 larvae of the Polychsta Magelona (very young), Pectinaria, and 

 Polydora, together with scores of Pilidium. Medusae were 

 very plentiful, especially the Leptomedusae Laodice criiciala, 

 Ohelicc, and an unidentified Irene-\-ik& Phialia, and, among 

 Anthomedusse, a small Margelid. There were also taken two 

 specimens of a species of Geryonia, and several of the amethyst 

 tentacled Amphinenia Titania (= Saphenia dinema of Foibes). 

 Noctibua has reappeared in small numbers. Evadne Nordmannt 

 is extremely plentiful ; Podon on the other hand is relatively 

 scarce. The following animals are now breeding : — The 

 Cladoceran Evadne Nordmanni (most carrying embryoes, some 

 provided with the "winter egg "), and a few Lobsters {Hotimrus 

 vulgaris). 



