Mar. 5, 1874J 



NA 7 URE 



34S 



be found sufficient to immerse it quickly under the acid, con- 

 tained in the beal<er (a), as shown in Fig. 3, where the induction- 

 tube is seen immersed to within 12 milhmetres of its upper sur- 

 face in water contained in an insulalcd cylindrical x'essel (A A'). 

 The inner cavity of the induction-tube is also filled with water to 

 .about the same level. By means of wires covered with caout- 

 chouc, except at the lower ends [p p'), the discharge from an 

 induction-coil, capable of giving 10 millimetre sparks in air, can 

 be passed through the apparatus. The water in A A' is main- 

 tained as steadily as possible at the temperature of the 

 apartment, and any slight changes in the course of the 

 experiment are noted by means of a delicate thermometer (t). 

 The variations of the barometer are also carefully observed. In 

 very exact experiments the surfaces of the induction-tube shoukl 

 be covered with tinfoil, and the cyUndrical vessel filled with ice. 

 Before commencing the observation, it will be found convenient, 

 if the temperature has not already effected the adjustment, to expel 

 a little oxygen from the induction-tube, so that the level of the 

 acid may stand some\\'hcre about /''. On passing the electiical 

 discharge, the aci'.l will at first be depressed a few millimetres, 

 from tlie repulsive action of the particles of the electrified gas, 

 but will afterwards steadily rise, and for some time with such 

 rapidity that the ascent of the acid column can be easily followed 

 by the eye. When the current is interrupted, a sudden rise of 

 the acid column will occur equal to the depression which took 

 place on first making connection with the induction coil, after 

 which the new level of the acid may be read. 



Another method of obtaining ozone is by the electrolysis of 

 water and of certain acid and saline solutions. The most conve- 

 nient liquid for this purpose is a mixture of one part of sulphuric 

 acid with six or eight parts of water, and the lower the tempera- 

 ture at which the electrolyte is maintained during the process the 

 greater is the amount of ozone. The simplest and most effi- 

 cacious arrangement for obtaining ozone by this method is one I 

 have used for many years and exhibited in my lectures. It consists 



of a bell-jar (Fig. 4, a), or glass cylindrical vessel, open below, and 

 contracted to a neck above, which is suspended in a round cell 

 (b I)'] of porous earthenware, leaving a clear space of two inches 

 between its lower edge and the bottom of the porous cell. The 

 whole is placed in a glass jar (cc') of somewhat larger dimensions 

 than the cell ; a bundle of platinum wires (/) suspended below 

 the bell-jar serves as the positive pole, and a broad ribbon of 

 platinum (h ;/) placed between the outer glass jar and the porous 

 cell as the negative pole of a voltaic arrangement of three or four 

 couples. A delivery tube hermetically united to the neck of the 

 bell-jar conveys the mixture of oxygen and ozone disen^iaged at 

 the positive pole to a sulphuric acid drying tube (d). From the 

 desiccating tube the gas passes through the connecting tube {<■) 

 and thence to other tubes, for the purpose of illustrating the pro- 

 perties of ozone. Thus, in the figure, it is represented as 

 traversing a tube of hard glass (//') covered with fine wire gauze, 

 and terminating near the surface of mercury contained in the 

 flask (//). So long as the gas is hen ted strongly as it passes 

 through the tubes ( //' ) by the spirit lamps,(4'/ ), not the slightest 

 change is produced upon the mercury ; but when the lamps are 

 removed, and the tube allowed to cool, the mercury is rapidly 

 attacked. I ought, perhaps, to mention that all the junctions 

 are made with dry and tightly fitting corks, care being taken that 

 the ends of the connecting tubes project a little beyond the 

 corks. With these precautions the loss of ozone, from its action 

 on the corks, is altogether insignificant. 



Ozone can also be obtained by the slow oxidation of phos- 

 phorus, and of certain ethers and essential oils in presence of 

 moisture. 



{To be continued.) 



NOTES 

 O.N'E of the last and one of the best acts of the late Govern- 

 ment was to grant a pension of 150/. a year on the Civil List to 

 Prof. Sharpey. Dr. Sharpey has done as much as any livin'' 

 teacher for the advancement of physiological knowledge, while 

 his personal worth has secured for him universal respect and 

 esteem. 



At the last monthly meeting of the Russian Imperial 

 Geographical Society M. ^'enioukoff, the secretary, before 

 proceeding with the business of the evening, said the Society 

 owed a duty which must first be fulfilled, and that was to render 

 homage to the memory of Dr. Livingstone, the importance of 

 whose discoveries and the perseverance of whose laliours had 

 placed him in the rank of the most remarkable travellers of all 

 times and of all nations. His biography belonged to the annals 

 of geographical science. M. Venioukoff then read a memoir of 

 Livingstone, which concluded as follows: — "Let England, 

 which may be proud of having given birth to Livingstone, and of 

 having supported him in his labours, learn that among us the 

 merit of her great men can be appreciated." The whole 

 assembly, which was very large, then rose in order to pay a last 

 tribute of respect to the memory of Dr. Livingstone. 



The University of St. Andrew's has conferred upon Mr. 

 J. Gwyn Jeffreys, F.R.S., the honorary degree of LL.D. 



We would draw special attention to the programme, whiih 

 has just been issued, of a new course of twelve lectures on 

 Zoology, to be delivered during the ensuing spring, in the Zoo- 

 logical Gardens, Regent's Park ; the Council of the Society 

 having determined to appropriate the interest of a small bequest 

 which they hold for scientific purposes — the Davis Fund — to the 

 subject. Mr. P. L. Sclater, F.R.S., the Secretary to the Society, 

 will deliver the Introductory Address on April 14 ; and he will 

 follow it by four lectures On the Geographical Distribution of 

 Mammals, After these Mr. A. H. Garrod, the Prosector to the 

 Society, will give five lectures On the General Classification of 

 the Vertebra ta ; and Dr. Carpenter, F. R.S., will conclude the 

 course by giving two On the Aquarium and its Inhabitants. The 

 lectures will be delivered on the Tuesdays and Fridays in April 

 and May, at 5 o'clock in the afternoon ; they will be free to 

 Fellows of the Society and their friends, and to other visitors to 

 the Gardens. The subjects will be treated in a manner which 

 will make them of general interest, and it is to be hoped that 

 ladies will avail themselves of the opportunity thus aficrded, of 

 obtaining information on this too much neglected branch of the 

 great science of Biology. 



Mr. Philip Barnes, who died on Feb. 24, at the age of S2, 

 was one of the oldest Fellows of the Linnean Society. He was a 

 native of Norwich, and a cousin of the Sowerbys. Thirty-four 

 years ago he founded the Royal Botanic Gardens in the Regent's 

 Park, and was the oldest Fellow and father ol the Society. A 

 portrait of Mr. Barnes was in the last International Exhibition, 

 and a bust in that of the year before. He \\as father of Robert 

 Barnes, M.D., and of the late Philip Edward Barnes, the 

 former known in the scientific world by his professional dis- 

 coveries and writings, and the latter the author of a work on the 

 Belgian Constitution. 



The death, from heart-disease, of Prof. J. F. Holton is an- 

 nounced as having taken place in Everett, Massachusetts, U. S., 

 on the 25th of January. Prof Holton was well known as a 

 botanist, having devoted many years to the study of the science. 

 He visited South America with special reference to prosecuting 

 his researches in this direction, ard studying the relation between 

 the physical geography and the vegetation of the Andes. His 

 somewhat extended sojourn in that country enabled him to col- 

 lect materials for a work, which was puMished afiir his return 

 by Harper and Brothers, and is frequently quoted by botanists. 



