244 



NA TURE 



\7an. 29, 1874 



the promotion of the interests of science, and for the 

 educational benefits that have been conferred through 

 their agency on all branches of the American community. 

 Learning some time since from a notice in NATURE that 

 Mr. Saville-Kent was about to resign his late curatorship 

 of the Brighton Aquarium, Messrs. Appleton at once 

 placed themselves in communication with that gentle- 

 man with the view of securing his aid in their scheme. 

 As a site, New York offers remarkable inducements for 

 the establishment of a marine and fresh-water aquarium 

 on the magnificent proportions intended, the sea and the 

 Croton river being equally available for the supply of the 

 two descriptions of water required, while as a position for 

 the acquisition of specimens to stock its tanks its advan- 

 tages cannot be over-estimated. The art of transporting 

 fish from one distant locality to another has been already 

 practised under the auspices of the " American Fisheries 

 Commission," on a larger scale and with more momen- 

 tous results than have been obtained on this side of the 

 Atlantic, through means of special cars fitted up with 

 tanks. These last appliances will prove of eminent 

 service and importance for the ordinary transfer of 

 aquarium specimens, while a slight modification of the 

 same might be adapted for accommodation on ship-board, 

 and for the conveyance of fish from distant seas. In 

 fact, starting with this proposed aquarium in the Central 

 Park, the future aim of high-class aquaria should and will 

 doubtless be, to as perfectly represent in its tanks the 

 marine fauna of every quarter of the globe as Menageries 

 and Zoological Gardens do at present the terrestrial 

 inhabitants. The most solid and important advantages, 

 however, likely to arise from an institution founded on the 

 basis of the New York scheme, are associated with the 

 pre-endowed system on which it is to be established ; this 

 of itself constitutes a guarantee for the attention to, and 

 accomplishment of, scientific results unattainable in connec- 

 tion with any similar undertaking set up as a mere commer- 

 cial speculation, and necessarily weighted with the many 

 antagonistic interests upon which its financial profits are 

 dependent. The time again could not be more ripe than 

 the present for projecting the proposed scheme, a 

 sufficient number of aquaria having been established in 

 this country and on the Continent to illustrate the advan- 

 tages or defects attendant upon the several principles of 

 construction which have been hitherto attempted, as also 

 to indicate the special modifications yet required to make 

 them thoroughly efficient for biological research. 



It is to be hoped that the meritorious example set by 

 America will not be lost on this country. England, with 

 her trreat resources, richly indented coast-line, and innu- 

 merable populous centres scattered along the latter, offers 

 remarkable facilities for the establishment of a large zoo- 

 lo"-ical station and aquarium, and which, conducted under 

 the auspices of a body of scientific men, with a trained 

 naturalist to superintend it, could not fail to yield the 

 most valuable results. In the absence of sufficient funds 

 forthcoming from private sources for free endowment, the 

 self-supporting system initiated by Dr. Anton Dohrn at 

 Naples offers singular advantages. His scheme of letting 

 out laboratory tables to various universities, governments, 

 and scientific bodies is particularly woithy of notice. The 

 fact that Cambridge has consented to take a share in one 

 of these tables, while testifying to the praiseworthy spirit 

 of that University, carries with it at the same time a se- 

 vere censure upon the insufficiency of the means provided 

 for scientific investigation nc.irer home. A well-appointed 

 marine aquarium with suitable laboratories established at 

 Torquay, Plymouth, or such other desirable locality, could 

 not tail to command the support of our leading English 

 universities, and it might be anticipated that also of many 

 others in France, Belgmm, Denmark, and other countries 

 of Northern Europe, too far removed to profit fully by the 

 advantages of the Naples station. Through the supply of 

 specimens for class demonstration, such an institution 



might also derive a considerable income. One of the 

 great disadvantages under which science courses are at 

 present conducted throughout this country arises from the 

 difficulty of obtaining for dissection typical examples of 

 the commonest representatives of our marine fauna and 

 flora, all of which might be furnished regularly and at 

 a low rate through the medium of a large seaside 

 aquarium, towards which is constantly flowing from every 

 side an amount and variety of material more than suffi- 

 cient for its own requirements. 



TUBES FOR SILENT ELECTRICAL DIS- 

 CHARGES * 



RUHMKORFF'S induction coil is now a classical 

 instrument found in every laborator)'. It is con- 

 stantly employed to obtain the sparks intended to com- 

 bine gases in eudiometric analyses, but its use is not 

 limited merely to effecting combinations, it effects also 

 decompositions, another property utilised in chemistry, 

 particularly to show that at the moment of its decomposi- 

 tion into nitrogen and hydrogen, aminonia gas doubles 

 its original volume. We never obtain, however, in this 

 experiment, a perfectly accurate result, for the induction 

 spark which separates the ammonia gas into its elements 

 is also capable of determining anew their combination to 

 reform the original gas. It exercises thus two actions 

 of a perfectly opposite kind, one of which seems due to 

 true electric action, and the other to the heat which 

 accompanies the passage of the spark. 



It would certainly be advantageous to separate these 

 two actions, since they are capable of acting in opposite di- 

 rections, and it is especially in the preparation of ozone that 

 this separation would be valuable, since ozone, which is 

 easily formed under the influence of the spark, is de- 

 stroyed by the action of heat. For the purpose of more 

 easily obtaining ozone M. Houzeau has recently con- 

 structed an apparatus worked by a Ruhmkorff coil, in 

 which there are no longer sparks, but only dark dis- 

 charges — c'fflii7'ia — far more efficacious in the production 

 of modified oxygen. 



It is known that at the end of last century, Van Marum 

 noticed a peculiar odour in the vicinity of an electric 

 machine giving large sparks, and that he attributed this 

 odour to electricity. In 1S40 Schccnbein showed that 

 oxygen disengaged by electrolysis from water has this 

 same odour, and preserves it after being kept in well- 

 stoppered phials ; he gave to the substance characterised 

 by this odour the name of ozone. 



There remained, however, some doubts as to the real 

 nature of this substance, until the investigations of M. 

 Marignac and of De la Rive in Switzerland, and MM. 

 Fremy and E. Becquerel in France. They succeeded in 

 demonstrating with precision that it was merely pure 

 oxygen which assumed, under the electric influence, a 

 new form. Researches on this modified oxvgen soon 

 accumulated, and chemists investigated it with the greater 

 ardour, thinking that in studying this particular form of 

 oxygen, they were touching that important question of 

 simple bodies which at present remains the "great un- 

 known '' of chemistry. 



-So far as research has gone, ozone appears to be a 

 strongly oxidising gaseous body, of one and a half times 

 the density of oxygen, and possessing affinities infinitely 

 more energetic than the latter. Thus it can oxidise cold 

 silver, which so strongly resists the action of ordinary 

 oxygen, it can inflame pure phosphuretted hydrogen, can 

 burn ammonia, transforming it into nitiic acid, and 

 can displace the iodine of iodide of potassium. All 

 these properties have been observed in the traces of ozone 

 contained in oxygen submitted to suitable treatment, and 

 the difficulty of obtaining appreciable quantities of ozone 



• Transbtcd from an article in La Xatiof. No. 20. 



