ArcusT 22, 1907] 



NATURE 



419 



Cologne have a two-fold object. In the first place Ihcy 

 imporl a new feature into medical study by introducing 

 newly qualified men to the practical side of medicine 

 more than is done at the universities. After the university 

 medical curriculum has been completed and the State 

 examination has been passed, the practical year which is 

 required by recent regulations may be spent at the 

 academics. Their second purpose is to supply the medical 

 practitioners of the district with opportunities for post- 

 graduate study. The Diissoldorf Academy is the first for 

 which clinics and lecture-rooms were specially built, 

 b?cau-.f at Cologne the e.xisting municipal hospitals were 

 adapted for teaching purposes. The structural and other 

 arrantjcments are described as excellent, and the clinical 

 material will be abundant. Prof. Witzel, formerly of the 

 University of Bonn, is the director of the new academy, 

 while the teaching staff includes Prof. Schlossmann in 

 the subject of pa;diatrics and Prof. Lubarsch in the sub- 

 jects of pathology and pathological anatomy. 



The Paris correspondent of the Chemist and Druggist 

 states that the committee on analytical methods has 

 defined the programme for the competitions for the prizes 

 offered for alcohol-denaturation in connection with the 

 law of November 29, 1905. This Act instituted two 

 prizes, one of 800/. for the discovery of a " denaturator " 

 more advantageous than those now used while safeguard- 

 ing the revenue against frauds, and a second (value 

 2000/.) for a system of utilising alcohol for lighting in 

 the same manner as parafTin. The denaturator must have 

 a taste and smell which will effectually discourage any 

 desire to use the alcohol as a beverage ; wine or date 

 must, oil of thyme and rosemary, and similar flavours are 

 thus eliminated. The denaturant should not be sufficiently 

 objectionable in smell to prevent its domestic or industrial 

 use — thus acetylene, asafetida, and garlic are excluded. 

 No soluble substance which could leave a deposit 

 on lamp-wicks, and thus render combustion diflTicult, may 

 be used, such as sea-salt, sodium sulphate, alum, 

 ammonium chloride, potassium ferrocyanide, picric acid, 

 tobacco-juice, and aloes. It must not consist of a sub- 

 stance much more or less volatile than alcohol, and which 

 could thus (besides other disadvantages) be removed by 

 fractional distillation, as ether, carbon bisulphide, light 

 fractions of petroleum or turpentine, cresyl, carbolic acid, 

 camphor, or naphthalene. It should contain no substance 

 which might injure the metailic part of lamps or motors 

 (ammonia, nitrobenzene, sulphuric acid). It should not 

 be poisonous (as mercuric chloride, methyl cyanide, sodium 

 arseniate, and aniline) or contain poison (hyoscyamus, 

 aconite, or digitalis). It should be sufficiently inexpensive, 

 should not normally exist in commercial alcohol, and its 

 presence in alcohol should be capable of easy and certain 

 detection. 



A PRIZE of 150/. is offered by the German Colonial 

 Society for a method to produce an extract from man- 

 grove bark that will impart as light a colour as possible 

 to leather, and such as will only slightly darken by 

 exposure to light. The mangrove bark contains a large 

 amount of tannin, and also a red colouring matter that 

 prevents the bark and its extract from successfully com- 

 peting with other tanning agents. The problem to be 

 solved is the practical removal of this red colour. Com- 

 petitors are invited to send in particulars of their methods 

 by July 20, 1908, to Deutsche Kolonialgesellschaft, 

 Schellingstrasse 4, Berlin. 



The Board of Agiiculture is considering the terms of 

 an order prohibiting the importation of plants and bushes 

 ^O. 1973, "^'OL. 76] 



bearing edible fruit, except by a licence to which con- 

 ditions will be attached, with the object of preventing the 

 introduction of the gooseberry mildew and other pests- 

 injurious to horticulture. 



AccORDl.^G to Engineerings, an Australian record in wire- 

 less telegraphy has been achieved by the successful trans- 

 mission of messages from H.M.S. Challenger, one of the 

 -Vustralian squadron at present stationed in Hobson's 

 Bay, to the flagship Powerful, which at the time was 

 moored in Farm Cove, Port Jackson. The Challenger 

 was in communication with the flagship by means of wire- 

 less telegraphy the whole of her voyage. The longest 

 message was one flashed over a distance of 410 miles in> 

 a direct line, and this constitutes an Australian record, as 

 previously never more than 240 miles had been achieved 

 by warships on the Australian station. 



.\ctORDlNC to Science, an equatorial telescope has been 

 given to the Nantucket Maria Mitchell Association, and 

 plans of an observatory to house the instrument are being 

 considered. An appeal has been made for funds properly 

 to equip the observatory that it may be available for 

 astronomy classes in the near future. 



.\ MEMORANDUM, dated August 5, issued by the Director- 

 General of the Egyptian Survey Department, on the 

 meteorological conditions of the monsoon season and the 

 prospects of the Nile flood, is far from encouraging. The 

 rains in June and July have been exceptionally weak, and 

 some i6 per cent, of an average flood volume may be 

 considered as deficient at the above date. On the whole. 

 Captain Lyons thinks it more probable that this deficiency 

 will be increased in August than that it will be diminished. 



Is the Meteorologische Zeitschrift (part iv., 1907) Dr. 

 V. Conrad gives an epitome of an interesting lecture 

 delivered by him on the formation and constitution of the 

 clouds. The author points out that to obtain a clear 

 idea of the subject we require to know (i) the size of the 

 separate fluid drops, (2) the rate of their descent, and 

 (3) the number contained in a cubic centimetre. -An idea 

 of the pains Jjestowed upon the inquiry may be formed 

 from the fact that sixty-nine references to authorities are 

 quoted in the paper. The size app<ars to have been first 

 microscopically measured by Kratzenstein, who published 

 the results at Haiie in I7<)6 ; recent measurements by 

 Assmann, Dines, and others give their mean diameter 

 as about 20 ft, or 10-' cm. radius. The vesicular theory 

 was not displaced until A. Waller published his paper in 

 the Phil. Trans, in 1847, and subsequent investigators 

 showed that the optical phenomena observed in clouds 

 could only be explained by the existence of complete 

 drops ; much information upon this subject will be found 

 in Dr. Pernter's " Meteorologische Oplik." The re- 

 searches of Stokes and others have shown that a droplet 

 of 10-' cm. radius would fall i cm. per second in calm- 

 air; with increasing radius, up to a certain limit, V in- 

 creases with r-, so that a drop of 10-' cm. radius would 

 attain a velocity of i metre per second. From independent 

 investigations the author found the number of drops 

 (r=io-' cm.) in a cubic metre of dense cloud to be 

 lo' (a thousand millions), or 1000 in a cubic centi- 

 metre. The question of the formation of the first con- 

 densation elements is one of great difficulty, since it has 

 been shown by Aitken and others that the presence of 

 some nucleus in the atmosphere is necessary ; possibly 

 observations made in balloons may eventually elucidate 

 the matter. 



