May 25, 1 893 J 



NATURE 



Ql 



was not le-ignited ; the bulk of the nitrogen was nearly five 

 minutes in boiling off, after which a smouldering splinter clipped 

 into the mouth of the test-tube burst into flame. 



Between the poles of the magnet all the liqueiied air went to 

 lhe poles ; there was no separation of the oxygen and nitrogen. 

 Liquid air has the same high insulating power as liquid oxygen. 

 '1 he phenomena presented by liquefied gases present an un- 

 limited field for investigation. At - 200° C. the molecules of 

 oxygen had only one-half of their ordinary velocity, and had lost 

 three-fourths of their energy. At such low temperatures they 

 seemed to be drawing near what might be called " the death of 

 matter," so far as chemical action was concerned ; liquid oxygen, 

 for instance, had no action upon a piece of phosphorus and 

 potassium or sodium dropped into it ; and once he thought, 

 and publicly stated, that at such temperatures all chemical action 

 ceased. That statement required some qualification, because a 

 photographic plate placed in liquid oxygen could be acted upon 

 by radiant energy, and at a temperature of - 200° C. was still 

 sensitive to light. 



Prof. M'Kendrick had tried the effect of these low tempera- 

 tures upon the spores of microbic organisms, by submitting in 

 sealed glass tubes blood, milk, flesh, and such-like substances, 

 for one hour to a temperature cf — 182° C, and subsequently 

 keeping them at blood heat for some days. The tubes on being 

 opened were all putrid. Seeds also withstood the action of a 

 similar amount of cold. He thought, therefore, that this ex- 

 periment had proved the possibility of Lord Kelvin's suggestion, 

 Ihat life might have been brought to the newly-cooled earth upon 

 a seed-beating meteorite. 



In concluding, the lecturerheartily thanked his two assistants, 

 Mr. K. N. Lennox and Mr. J. \V. Heath, for the arduous work 

 they had had in preparing such elaborate demonstrations. 



SCIENTIFIC SERIALS. 



In the Jotirnal of the Royal AgricUllural Society of England 

 (third series, vol. iv. pt. I) there is an interesting paper on the 

 home produce, imports, consumption, and price of wheat over 

 forty harvest years, 1852-3 to 1891-2, by Sir J. B. Lawes and 

 Dr. J. H. Gilbert. This .paper, extending to fifty-five pages, 

 contains a general review of the produce of the experimental 

 plots at Rothamsted, from which they have annunlly calculated 

 the wheat crop of this country. — The first of the official 

 reports is that of the Royal Veterinary College on investigations 

 conducted for the Royal Agricultural Society during the year 

 1S92. An interesting case of actinomycosis is related ; a heifer 

 with tongue badly diseased was put under Thomassen's treat- 

 ment. Potassium iodide administered at first in doses of one 

 drachm, twice daily, and the do^es gradually increased to three 

 di-achms, effected a complete cure in about ten weeks. — Experi- 

 ments have lately been made at the Veterinary College with 

 Koch's tuberculin. The results in the case of seventy-two 

 animals inoculated and afterwards killed show that " the tuber- 

 culin pointed out correctly the existence of tuberculosis in twenty- 

 seven animals and wrongly in five, and it failed to indicate the 

 existence of the disease in nineteen. In only three of the twenty- 

 seven animals in which the tuberculin correctly pointed out the 

 existence of tuberculosis could a positive diagnosis have been 

 made by any other means." Experiments have also been made 

 with Kalning's mallein, and "the results warrant the statement 

 that mallein is an agent of greater precision than tuberculin, 

 and that it is likely to render most important service in any 

 attempt to stamp out glanders." 



IViedemaiin's Annalen der Pliysik uiij C/ieiiiie, No 4. — On 

 electric discharges ; the production of electric oscillations, and 

 their relations to discharge tubes, by H. Ebert and E. Wiede- 

 mann. The influence of electric oscillations of given frequency 

 in producing glow in vacuum tubes without electrodes was 

 investigated by means of Lecher's wire system. The oscillations 

 in the primary circuit were produced by means of an influence 

 machine throughout. The terminals of the machine were con- 

 nected to the primary condenser, consisting of four plates, to 

 the further two of which the two Lecher wires, copper wires or 

 I hick metal tubes, were attached, running parallel for distances 

 varying from 2 to 14 m., and ending in another condenser of 

 variable capacity. The sensitive tubes were placed in various 

 positions between or near the plates of the secondary condenser. 



NO. 1230, VOL. 48] 



It was found that wide tube^, not too jhort, glowed most readily- 

 Nodes along the wires were discovered by means of wire bridges, 

 which were moved along the wires until the tube glowed, or, it 

 it was glowing already, until it reached a point where the glow 

 became more intense and uniform. It was found that the position 

 of the nodes was independent of the pressure in the tube, but 

 that as evacuation proceeded the limits within which the tube 

 would glow grew wider. Hence the most accurate method for 

 finding the nodes, was by finding them for the highest possible 

 pressure of gas in the tube. — On the comparison of intensities 'if 

 light, by the photoelectric method, by J. Elster and H. Geiiel. 

 Apart from the dissipation of an electric charge from a negative 

 zinc pole by ultra-violet radiation, it is also possible to measure 

 the intensity of optically active light by an electric method. If 

 a clean surface of potassium is joined to the negative pole of a 

 battery, and a platinum or aluminium electrode to the positive 

 pole, and the two electrodes are placed in a vacuum cell, the 

 illumination of the potassium surface will allow a current to 

 flow whose strength will be proportional to the intensity of the 

 light source, and can be measured by means of a galvanometer. 

 That this is really the case was proved by measuring indepen- 

 dently in this way the intensities of two luminous sources, and 

 then combining them, when the resultant reading was found 10 

 be equal to the sum of the other two, within the limits of con- 

 stancy of the sources themselves. The greatest effect is produced 

 by the blue rays. — Also papers by Messrs. Bjerknes, Zahn, 

 Voigt, Richarz, Ambronn, Christiansen, Goldhaminer, and 

 Oberbeck. 



Metcoi-ologischc Zcitschrift, March.— Iridescent clouds, by 

 II. Mohn. — The paper contains observations made at Chris- 

 tiania during the years 1871-1892, together with a detailed 

 investigation of the formula; recently employed. During this 

 period iridescent clouds were only visible on forty-two days ; in 

 some years the phenomenon failed entirely, and was not ob- 

 served during the whole lustrum 1876-80. The great majority 

 of cases occurred in December and January, but a few occurred 

 in summer ; the phenomenon was also .'een somewhat more 

 frequently at sunset than at sunrise or mid-day, but the difference 

 is so small as to make it appear that its occurrence is inde- 

 pendent of the time of day. The height of the clouds varied 

 from about fourteen 4o more than eighty miles, the lower 

 level being about twice the height at which ordinary cirrus 

 clouds are usually seen at C hristiania. The phenomenon appears 

 to have some connection with the state of the weather, as an 

 examination of the synoptic charts showed that it mostly occurred 

 during the prevalence of stormy weather in the North Atlantic 

 and over Northern Europe, and when the air was dry and waim 

 at Christiania. — On the determination of wind force during gusis 

 of a Bora storm, by E. Mazelle. From an investigation of the 

 anemometer observations at Trieste for the ten years 1882-1S91, 

 the greatest hourly velocity recorded was seventy miles. But as 

 hourly values give little idea of the violence of individual gusts, the 

 author adapted an ingenious electrical arrangement to the anemo- 

 meter, by which he could record the number of revolutions of the 

 cups in each second. During a storm on January 16 last, the 

 gusts during the space of a few seconds reached the velocity 

 equivalent to 100 to 140 miles an hour. Presuming the instru- 

 ment to have been a large-sized anemometer, this high velocity 

 is not unlikely, as in a paper read before the Royal Meteoro- 

 logical Society on May 18, 1881, by R. H. Curtis, a velocity at 

 the rale of 120 miles an hour at Aberdeen is quoted as recorded 

 in gusts lasting two minutes, while shorter intervals, if they 

 could be measured, would no doubt show higher velocities ; and 

 at Sydney a velocity of 153 miles an hour was recorded during 

 one or two minutes. In all these cases the factor 3 has 

 been used for the ratio of the movement of the cups to that of 

 the wind, but this factor h.is been shown to give a velocity which 

 is nearly 30 per cent, too high. 



BulleHn dela Socit'lc des NtitiiralUles de Moscon, 1892. — (No. I.) 

 The chief papers are : — The development of the gemmula; in 

 Ephydatia fliivialilis, by W. ZykoflF. — Catalogue of Kazan 

 Lepidoptera, continued, by L. Kroulikovsky. — Analogy between 

 the solution of a gas and of a salt in indiff'erent solutions of 

 salts, by I. M. Syelchenoff. The author's law, which was found 



or carbon dioxide (y = ae - |, holds good within certain 



limits, for the solution of sails in the same solutions ; but the 

 latter must only be taken eiiher weaker of medium strength- — 

 New plants and insects from Sarepta, by Alex. Becker.-^On a 



