October 5, 191 1] 



NATURE 



459 



the Journal of the Franklin Institute for September, Dr. 

 E. F. Northrup, of Princeton University, has so materially 

 the apparatus used in their production that 

 accurat-- observations of them may now be made. A 

 coloured ring of liquid is projected from the opening in 

 the front of a metal box by a blow struck by an electro- 

 magnet on the back, and travels through a transparent 

 liquid, which gradually decolourises the projected liquid. 

 If the box is pointed slightly upwards, the issuing vortex 

 ring is reflected on reaching the surface of the liquid, the 

 angle of reflection being apparently equal to that of 

 incidence. By the use of two liquids of different densities 

 in the observing tank, refraction may also be shown. 

 While, however, the actual matter of the vortex ring is 

 carried forward into the second liquid if the density of the 

 latter is greater than that of the ring, this is not the case 

 if the ring is denser than the liquid into which refraction 

 is about to take place. By projecting molten paraffin wax 

 into cold water, solid rings can be obtained. A subsequent 

 number of the Journal will contain photographs of rings in 

 a variety of conditions. 



We have received from the authors, Messrs. H. R. 

 Hamley and A. L. Rossiter, a copy of a paper on the 

 magnetic properties of stalloy, reprinted from the Proceed- 

 ings of the Royal Society of Victoria. The remarkable 

 magnetic properties of stalloy — essentially an iron-silicon 

 allov containing 3-4 per cent, of silicon — have already been 

 investigated very fully in this country, principally by 

 methods involving the use of a wattmeter ; the present 

 research emanates from two Government research scholars 

 working in the University of Melbourne, and the methods 

 used are entirely different, since they depend upon Prof. 

 T. R. Lyle's method of tracing out the wave-forms. This 

 application of Lyle's method is interesting, and it is satis- 

 factory to find that the results substantially confirm those 

 obtained by the wattmeter methods. 



Three interesting equilibria are discussed in the Memoirs 

 of the College of Science and Engineering of the Kyoto 

 Imperial University, the third volume of which is now 

 being issued. In the case of sodium acetate dissolving in 

 acetic acid solutions of different strength, the complete 

 equilibrium diagram for 20 C. plotted by R. Abe shows 

 the existence of three salts having the formula; 



NaC.H,0.„3H,0 ; NaC.H ,0„,C.H,0., and 



NaC = H 3 0,, 20,11,0,. 

 In the case of sodium and potassium carbonates dissolving 

 in water at 25° C, V. Osaka finds that the only double 

 salt which can exist in contact with its solution at that 

 temperature is the salt XaXO,,K,CO,,i2H.O. In the 

 case of the system water, ethyl alcohol, ethyl ether, studied 

 by S. Horiba, physical methods of analysis were adopted, 

 the composition of the phases being determined from 

 measurements of density, refractive power, and viscosity. 

 The critical composition at which the two phases become 

 identical was found to be : water 40 per cent., alcohol 

 2S-4 per cent., ether 316 per cent., for a temperature of 

 jfe" C. 



Some months ago attention was directed in these columns 

 to a paper by Flint in The American Journal of Science, 

 in which he claimed to have separated, by fractional pre- 

 cipitation of tellurium tetrachloride, a portion of the 

 tellurium with an atomic weight so low as 124-32. This 

 method of resolution had already been tried some years 

 previously by Baker and Bennett, but without success. In 

 view of the results recorded by Flint, Prof. Baker re- 

 peated his experiments in collaboration with Prof. Vernon 

 Harcourt, and found once more that no resolution could 

 be effected by this method. In describing their experi- 

 NO. 2l88, VOL. 87] 



ments in the Journal of the Chemical Society, these authors 

 explain the probable origin of the anomalous results of 

 the American observer. In recovering the tellurium which 

 they had used, they noticed that an orange-coloured pre- 

 cipitate was formed from material that had previously 

 been quite white. This yellow precipitate was found to be 

 tellurium trioxide, which had been produced by the 

 oxidising action of hydrochloric acid previously exposed to 

 bright sunlight, and thereby contaminated with chlorine. 

 .1 basic nitrate prepared from the trioxide and analysed 

 by Flint's method gave (on the assumption that the 

 tellurium was present as dioxide in the form 2TeO,,HNO a ) 

 an atomic weight so low as 118-31, instead of the normal 

 value 127-54. There can be little doubt, therefore, that the 

 low figures given by Flint were, due to oxidation of the 

 material, and not to any resolution of the element. 



The City of Paris depends upon its supply of fuel, food, 

 and other commodities to a large extent on the traffic 

 carried by water, the quantity brought into the city by 

 this means of transport being greater than by the 

 railways. Ever since the formation of the Manchester 

 Ship Canal, the question of rendering the Seine between 

 Rouen and Paris navigable for sea-borne vessels has been 

 in agitation. The serious inundations that occurred in 

 the lower parts of Paris about a year ago again directed 

 attention to the condition of the river, and a commission 

 was appointed by the Minister of Public Works to report 

 on the matter. Recently this commission has presented its 

 report. The question of making the river navigable for 

 sea-borne vessels, and making Paris a seaport, is not, 

 however, dealt with, the commission being of opinion that 

 the present conditions of traffic can be considerably 

 improved by the works proposed for dealing with the 

 prevention of overflow and inundations. The widening 

 and deepening of the channel in some parts where required, 

 and the construction of a new channel across the bend 

 between the Rivers Marne and Seine below Paris, pro- 

 posed by the flood commission, would be of great service 

 to the traffic. A large sum of money has already been 

 expended in enlarging and improving the locks and the 

 channel between Rouen and Paris, and boats carrying 

 more than 200 tons can navigate the waterway. 



Commenting on the wreck of the naval airship at 

 Barrow on September 24, The Engineer for September 29 

 believes that had this vessel survived a few months longer 

 even the Admiralty officials responsible for her inception 

 would have become convinced that the airship in general 

 is a hopelessly impracticable affair. The vessel will in all 

 likelihood be repaired ; indeed, even already there is news 

 to this effect. Sufficient has not yet been done, our con- 

 temporary supposes, to justify the official abandonment of 

 the whole idea. Engineering of the same date is more 

 sympathetic, and considers that it would be a mistake to 

 attach too much importance to the accident. The airship 

 is still, like the aeroplane, in an experimental stage ; and 

 the Admiralty airship must be regarded as a great practical 

 experiment, in which the results of trial and error, when 

 carefully analysed, must yield important lessons. The 

 material used for the outer envelope proved of high resist- 

 ing quality, only yielding when there was abnormal tension. 

 The duralumin girder-work proved very ductile and of 

 great tensile strength against the racking stresses set up. 

 The material of which the ballonets are made, as sup- 

 plied through the War Department, has all along been a 

 source of uncertainty and of little accidents, and the facts 

 point to the cause of the collapse being due to the rupture 

 of a gas-bag when the vessel was being drawn out of the 

 shed. 



