NA TURE 



[Nov. 7, 18S9 



'thus being collected ; and he trusted that fresh light would be 

 thrown on the subject of coincidental or veridical hallucinations, 

 •which specially interested their Society. He would be glad to 

 supply information in reply to letters addressed to him at Hill 

 Side, Cambridge. A paper on recent telepathic experiences 

 •was also read. 



We learn from Humboldt that the project of a lacustrine bio- 

 logical station on Lake Plon, in East Holstein, is likely to be 

 soon carried out, thanks to the energy of Dr. Otto Zacharias, 

 and the liberality of the Bohemian Baron Bela Dertcheni. This 

 station is to afford Prof. Anton Fritsch, of Prague, and his 

 assistants, constant opportunities of research on fresh-water 

 fauna. The scheme finds a good deal of favour in Berlin, and 

 it is hoped that the researches at the station may prove of 

 ■considerable benefit to fisheries. 



We send to America some return for the Colorado beetle and 

 the Canadian water-weed. The "weed-law" of the State of 

 Wisconsin requires from farmers, under penalties, the destruc- 

 tion of the following weeds : — Cnicus arvensis, Arctium Lappa, 

 ■Chrysanthemum Leiicanthemum, Sonchus arvensis, Xanthium 

 strutnariiun, Linaria vulgaris, and Rumex crispus. Only one of 

 these is a native of the United States ; all the rest being natural- 

 ized importations from Europe, and common wild plants in this 

 country. 



Prof. Righi showed, last year, that ultra-violet radiations 

 reduce to the same potential two conductors, a plate and a piece 

 of netting, applied to each other, the rays being thrown on the 

 netting-side. He now points out {Riv. Sci. Ind., July-August) 

 that this suggests a very simple and convenient way of measuring 

 differences of potential of contact. One notes the deflection of 

 an electrometer connected with the plate (the netting being 

 permanently connected with earth) ; then, having connected the 

 electrometer for an instant with earth, makes the radiations act a 

 sufficient time. He used a zinc electric lamp, and the metals 

 examined were placed in some cases in a bell jar, to which some 

 gas or vapour was admitted. From measurements of different 

 plates with the same metallic net (copper, zinc, or platinum), 

 the differences of potential of pairs of metals could be deduced. 

 Prof Righi found the differences sensibly the same in dry and 

 moist air and in carbonic anhydride; but with hydrogen, very 

 -different values (from those in air) appeared, where one of the 

 metals examined was platinum, palladium, nickel, or iron 

 (doubtless owing to absorption). In ammonia all the metals, 

 examined with zinc net, seemed to have become less oxidizable ; 

 ^nd in coal gas, carbon and platinum behaved like more 

 oxidizable metals. A memoir on the subject will shortly 

 appear. 



In an interesting paper on the management of aquaria, printed 

 in the Bulletin of the United States Fish Commission, Mr. W. 

 P. Seal points out that, in the feeding of the fish, care must be 

 taken to introduce no more food than they can eat in a short 

 time, as what is not eaten will soon decompose and make the 

 water cloudy, and generate noxious gases as well. If due care 

 is observed in regard to quantity, it does not matter how often 

 fish are fed, except that if fed abundantly they will grow rapidly, 

 which is not generally desired. Fish may be fed every day, or 

 but two or three times a week, with equally good results appar- 

 ently. They will always find a small amount of food in the 

 aquarium in the vegetation. Where they are not fed sufficiently, 

 •they are apt to strip the plants of their leaves. In a natural 

 •condition fish are feeding continually and grow very rapidly. 



On November 2 a slight shock of earthquake was felt in St. 

 Louis, U.S.A., and the vicinity. 



The following summary of the phases of Vesuvius during the 

 ipast year has been supplied by Prof. Palmieri, of the Vesuvian 



Observatory of the University of Naples, to the British Consul 

 there, and is appended by the latter to his last Report. Mount 

 Vesuvius, during the past year, has continued its moderately 

 eruptive activity, which began in the month of December 1875. 

 There were various emissions of small lava stream^, which did 

 not reach further than the base of the cone. An additional cone 

 was gradually formed, caused by the activity of the motive power 

 of the crater which, towards the end of the year, had reached a 

 height of 100 metres (equal to 328 feet) above its original level. 

 On various occasions the detonations and the red-hot projectiles 

 thrown up with the large quantities of smoke indicated greater 

 eruptive power. During the whole year no ashes were thrown 

 up, and consequently the crops in the surrounding country were 

 not destroyed. The sublimations on the smoke issues were 

 relatively scarce, and did not present any product that called 

 for attention. The seismographic instruments at the Observa- 

 tory did not show an activity proportionate to that of the 

 volcano. All the lava streams that issued during the year 

 flowed towards the eastern slopes of the mountain. 



The Meteorological Council have published Part I. of the 

 Quarterly Weather Report for 1880. The work is (as before) 

 divided into three sections : (i) a general summary of the chief 

 features of the weather for the quarter ; (2) tables showing the 

 movements and peculiarities of the principal cyclonic and anti- 

 cyclonic systems ; and (3) remarks on the distribution of the 

 various elements for each month, illustrated by charts. An 

 appendix contains tables and diagrams illustrating the diurnal 

 range of the barometer in Great Britain and Ireland during the 

 years 1876-80, by F. C. Bayard. The data used are the hourly 

 observations at seven Observatories in connection with the 

 Meteorological Office, and at Greenwich and Liverpool Observa- 

 tories. The paper shows that, even in these high latitudes, the 

 daily range is well marked during all months, notwithstanding 

 the interference caused by non-periodic changes. Important 

 seasonal differences are shown, the morning maximum being 

 distinctly higher than the evening maximum in winter, while in 

 summer the evening maximum is the higher of the two. The 

 values exhibit the influence of locality on the amplitude and 

 epoch of the diurnal inequalities, and furnish material for more 

 minute inquiry. 



It is interesting to read of a part of the world where the buffalo 

 is not dying out, but increasing in numbers. A journal of Perth, 

 in Western Australia, says that few Australians are aware that 

 certain parts of Northern Australia have vast herds of the wild 

 buffalo {Bos bubalus) careering over its plains and wallowing in 

 its shady pools. The Sydney Mail states that the animals are 

 massive and heavy, with splendid horns, and afford sport of a 

 sufficiently dangerous nature to possess charms for the most 

 daring hunter, a wounded buffalo being one of the most dangerous 

 animals known, his great weight, prominent horns, and splendid 

 CDurage, making him as well respected as sought after. The first 

 buffaloes were landed at Port Essington, North Australia, about 

 the year 1829. 



The Naturalisf s Gazette has issued an excellent series of 

 what it calls "label lists." On one sheet there is a list of British 

 birds' eggs ; on another, a list of dragon-flies ; on another, a list 

 of British butterflies ; and so on. The names are printed in 

 suitable type on gummed paper, and collectors, in labelling 

 their specimens, will find the lists of considerable service. 



The next volume of Messrs. Ward, Lock, and Co.'s "Minerva 

 Library of Famous Books " will be " Travels on the Amazon 

 and Rio Negro," by Dr. Alfred Russel Wallace. 



F. A. Brockhaus, 16 Querstrasse, Leipzig, has issued a 

 catalogue, in four parts, containing lists of works relating to 

 various branches of botany. 



