October ii, 1900] 



NA TURE 



577 



organisms could be isolated from the sap — the infectious 

 nature of which he also proved — which will reproduce the 

 disease, and since the same s^:^ filtered through porcelain 

 still infects the plants, unless it was previously sterilised 

 by heating, the causal agent must be a contagtum 

 7>ivutn fluidum — a something of the nature of a poi- 

 sonous enzyme, which not only diffuses through the 

 plant-membranes — e.g. the cell-walls of root-hairs — but 

 increases as it passes from cell to cell. 



Koning confirms Beijerinck's principal results, but con- 

 cludes that since the infecting fluid may be heated to 

 100° C. for a few minutes without losing its powers, 

 whereas alcohol and glycerine destroy the virulence, as 

 also does repeated filtration through porcelain, the active 

 agent is an extremely minute organism., which can 

 traverse the pores of a filter. He compares the results 

 with those obtained with the virus of various animal 

 diseases from which no organism has as yet been 

 isolated. 



It should be borne in mind that the existence of 

 organisms small enough to pass through a porcelain 

 filter has been accepted by several authorities. 



When we reflect that well-studied micrococci are 

 only o'5 -o'8 /* in diameter, and that the wave-length of 

 those light rays corresponding to the sodium-line D is 

 about 0-6 fi, some of these matters become less astounding : 

 organisms i/5th to i/ loth this size would probably be well 

 beyond the powers of our best lenses, and would roll 

 through the pores of a filter as shot through the meshes 

 of a sieve. 



It thus appears that — without regarding the work 

 as quite conclusive, which it is not — we have here 

 important contributions to several most weighty biological 

 questions centred about the culture of an economic 

 plant. 



NOTES. 

 The International Congress of Botany was opened in Paris on 

 the 1st inst., and was in session until Tuesday last. M. Prillieux 

 was the president.; 



The new science laboratories at King's College, London, are 

 to be opened on the 30th inst. by Lord Lister. 



Another death from plague has occurred in Glasgow, 

 bringing the number of fatal cases in hospital since the out- 

 break up to six. A fatal case of plague is also reported from 

 Llandatf. 



A Reuter telegram announces the arrival at Copenhagen, on 

 October 4, of Lieut. Amdrup and all the members of his 

 expedition. From July 18 to September 2 the expedition, 

 while engaged on the coast of Greenland, explored and mapped 

 out a stretch of land hitherto entirely unknown and 

 extending from Cape Dalton, 69°28', to Aggas Island, 67^22'. 

 Lieut. Amdrup is reported to have brought with him important 

 collections, the results of his researches. The Antarctic reached 

 Tasiusak on September II, and sailed thence on her return 

 journey on September 18. 



The Athenaeum states that the Kolthoff Arctic Expedition 

 has succeeded in bringing to Sweden a male and a female calf of 

 the musk ox {Ovibos moschatus, Gmelin). As soon as the 

 animals appear to be acclimatised they are to be set free in the 

 northern mountain regions, where it is thought they will speedily 

 increase in number, as they are very prolific. Herr Kolthoff has 

 great faith in the future importance of the musk ox, not so much 

 as an article of food as on account of its thick brown wool, which 

 is said to be remarkably strong. 



NO. 161 5, VOL. 62] 



The petrified remains of the extinct rhamphorhynchus have 

 been discovered in the stone quarries of Eichstiitt, Bavaria. It 

 is stated that the teeth and fingers are very distinct, and that the 

 membrane between the fingers is visible in places. 



According to the Exchange Gazette of St. Petersburg, the 

 question of the official introduction of the metric system of 

 weights and measures into Russia has been decided in principle 

 in an affirmative sense. The Ministry of Finance is now con- 

 sidering in what manner, and when, the projected reform shall be 

 carried out. 



The trustees of the American Medical Association have estab- 

 lished a fund of 500 dollars, to be expended annually for the 

 encouragement of scientific research ; but no individual is to 

 receive more than 1 00 dollars at one time. 



The lecture arrangements of the London Institution for the 

 session terminating on February 28 next have now been com- 

 pleted. The science lectures are as follows : — '* The Rise of 

 Egyptian Civilisation," by Prof. Flinders Petrie ; " The Earth's 

 Beginning," by Sir Robert Ball ; "The Earth's Earliest In- 

 habitants," by Prof. Grenville Cole ; " The Caves of Jenolan," 

 by Mr. F. Lambert ; " The Tercentenary of the Science of 

 Electricity," by Prof. Silvanus Thompson ; *' The Evolution of 

 the Brain," by Dr. Alex. Hill ; " Modern Aeronautics," by 

 Mr. Eric S. Bruce ; "The First Ascent of Mount Kenya," by 

 Mr. H. J. MacKinder ; The Effect of Alcohol on the Nervous 

 System," by Prof. Victor Horsley ; " The Decorative Art of 

 Primitive Peoples," by Prof. A. C. Haddon ; and " Aquatic 

 Autocrats and Fairies," by Mr. F. Enock. The Christmas 

 course, intended for juveniles, is to be delivered by Prof. 

 W. B. Bottomley, and will be devoted to " Structure and 

 Colour," " Insect Visitors," " Unbidden Guests," and " Place 

 in Nature." 



The next meeting of the Royal Microscopical Society will 

 be held on Wednesday, the 17th inst., when Part ix. of a report 

 on the recent Foraminifera of the Malay Archipelago will be 

 presented. Preceding the meeting there will be an exhibition of 

 slides and models of skin structure, by Mr. F. W. Watson 

 Baker. 



The first monthly general meeting of the new session of the 

 Institution of Mechanical Engineers will take place on Friday, 

 October 19, when a paper, entitled "Observations on an 

 Improved Glass Revealer for Studying Condensation in Steam 

 Engine Cylinders and rendering the Effects Visible," will be 

 read by Mr. Bryan Donkin, and discussed, 



A new monthly meteorological journal has recently made its 

 appearance in Holland, and bears the name of Nederlandsch 

 Tijdschrijt voor Meteorologie. The style of the journal is 

 popular in character. 



The current Geographical Journal publishes further details as 

 to the programme of Dr. Sven Hedin's journeys in Northern 

 Tibet and neighbouring regions for the present year. At the 

 time of sending his last letter, on June 27 last, the explorer was 

 about to start for the Chamen Tagh, whither his caravan had 

 already preceded him, his intention being to cross the Astyn Tagh 

 and Koto-Shili ranges, so as to obtain a geological section of the 

 country, and correct his route with that of his former Tibetan 

 journey. After returning to his headquarters in the Chamen 

 Tagh, he hoped to make his way across Northern Tsaidam to 

 Sachu, and thence west to the old bed of Lob Nor, continuing 

 his investigations of the latter end of the ruins in its vicinity. 

 Thence he proposed to carry a chain of altimetric observations 

 to Kara-koshun and Chaklik. He hoped to arrive at the last 

 named point by about January 1, 1901. 



