September 23, 1922] 



NA TURE 



43i 



Potato Trials at Ormskirk. 



SIR DANIEL HALL, Chief Scientific Adviser of 

 the Ministry of Agriculture, presided at the 

 public inspection at Ormskirk on August 24 of the 

 eighth series of annual trials of new potato varieties 

 for immunity from Wart Disease (Synchitrittm endo- 

 bioticum). In addressing the important gathering of 

 growers and scientific workers, Sir Daniel expressed 

 the view that the disease must inevitably spread over 

 the whole of Great Britain. The only known pro- 

 tection against the disease is to plant varieties which 

 are immune from its attacks ; unfortunately the most 

 popular of the varieties at present grown are not 

 immune. The production of new immune varieties 

 with good cropping, cooking, and keeping qualities is 

 therefore essential, and it was with the view of enabling 

 raisers to ascertain whether their new prodvictions 

 would resist the disease that these trials were begun 

 in 1915. In that year 94 stocks were sent for test ; 

 the trials have been largely developed by the Ministry 

 of Agriculture, and since 1920 have been carried out at 

 the Potato Testing Station of the National Institute of 

 Agricultural Botany. This season 2500 stocks were 

 planted. In an attempt to keep the spread of the 

 disease within bounds the Ministry issues annually a 

 list of new varieties which have proved immune in 

 the trials. Only listed varieties may be planted in 

 infected soil, or sent away from infected areas for 

 seed purposes. Before a variety is regarded as immune 

 it must have been grown at Ormskirk for two con- 

 secutive seasons without succumbing. Supplement- 

 ary one-year trials of small stocks (not exceeding ten 

 tubers) of seedlings are conducted for the information 



of raisers, but these trials are not taken into account 

 by the Ministry in drawing up the list of immunes. 



It is apparent from the results of the last two 

 seasons that the rainfall affects the incidence of the 

 disease. In the dry summer of 1921 the disease 

 appeared very late, and its attacks were less severe ; 

 this season, with much rain, the disease has appeared 

 earlier and is very marked. Of the 91 new stocks 

 that are being tested for the second season, 19 have 

 so far succumbed, though they escaped last year. 



There are 123 stocks under trial for the first time 

 this season : 58 have already succumbed and 48 

 cannot be distinguished from previously existing 

 varieties. The number of varieties entered as new 

 but in fact identical with older varieties is, however, 

 much smaller than in previous years owing to the 

 activities of the Synonym Committee of the National 

 Institute of Agricultural Botany. The one-year seed- 

 ling trials occupy 1700 of the 2500 plots, and 500 are 

 planted with stocks of established varieties for demon- 

 stration purposes. 



The Institute is also conducting, for the second 

 year, trials to establish the relative dates of maturity 

 of nine important first earlv varieties, and the in- 

 fluence of source of seed on date of maturity and yield. 

 The trials are composed of three chequer boards, one 

 consisting of all 9 stocks drawn from 8 different 

 districts, one of all 9 stocks from one district, and 

 the third of one stock drawn from all 8 districts. 

 The results should also be of value in indicating 

 the most accurate method for conducting yield 

 trials. 



International Reunion of Chemists at Utrecht. 



ON June 21, 22, and 23 there was held at Utrecht 

 an international reunion of chemists, which 

 was organised by Profs. Ernst Cohen, H. R. Kruyt, 

 and P. van Romburgh, of the University of Utrecht. 

 Among those also present may be mentioned : — 

 Abel (Vienna), Backer (Groningen), Baly (Liverpool), 

 Billiter (Vienna), Bjerrum (Copenhagen), Bodenstein 

 (Hanover), Blanksma (Leiden), Bredig (Carlsruhe), 

 Bronsted (Copenhagen), Centnerschwer (Riga), Dennis 

 (Ithaca, X.Y.), Donnan (London), Dubsky (Brunn), 

 Enrich (Graz), Hahn (Berlin - Dahlem), Holleman 

 (Amsterdam), Maclnnes (Cambridge, Massachusetts), 

 Jaeger (Groningen), Jorissen (Leiden), Kailan 

 (Vienna), Klemenc (Vienna), Lewis (Liverpool), Noyes 

 (Urbana, Illinois), Petersen (Copenhagen), Pfeiffer 

 (Bonn), Piccard (Lausanne), Pregl (Graz), Reinders 

 (Delft), Schenck (Minister), Schilow (Moscow), Schlenk 

 (Berlin), Simek (Brunn), Skrabal (Graz), Stock (Berlin- 

 Dahlem), Walden (Rostock), Wegscheider (Vienna), 

 Wieland (Freiburg in Breisgau), and Whither (Copen- 

 hagen). 



During the scientific meetings a number of very 

 interesting papers were read, which gave rise to good 

 discussions. Among these may be mentioned the 

 following : photochemical catalysis (Baly) ; the 

 photochemical combination of hydrogen and chlorine 

 (Bodenstein) ; free radicals (Walden) ; contributions 

 to the chemistry of the free radicals and the variable 

 affinity-value of the carbon linking (Schlenk) ; free 

 radicals (Wieland) : positive and negative valence 

 (Noyes) ; the preparation and properties of metallic 



NO. 2760. VOL. I lOj 



germanium (Dennis) ; absorption colours of the 

 second order (Piccard) ; and adsorption and dis- 

 tribution (Schilow). 



The chemists attending the meeting received the 

 heartiest of welcomes and the most lavish hospitality 

 from their Dutch colleagues, who arranged a series of 

 lunches, dinners, and excursions. Few of those who 

 were present will ever forget the splendid hospitality 

 of Holland, the excellence of the arrangements, and 

 the atmosphere of good fellowship which characterised 

 the meeting. 



On the afternoon of the second day a reception was 

 given by the Dutch Chemical Association, while on 

 the afternoon of the last day the members were 

 invited to tea by Count Dr. van Lynden van Sanden- 

 burg, Governor of the Province of Utrecht, and 

 Countess van Lynden van Sandenburg. The meeting 

 concluded with a banquet at the Badhotel, Baarn, 

 which was preceded by a visit to the beautiful Botanic 

 Gardens of the University of Utrecht. 



The heartiest thanks of all the chemists who 

 attended the meeting are due to Prof. Ernst Cohen, 

 who acted as a most genial and efficient president, to 

 his collaborators, and to all those in Holland who 

 subscribed so liberally towards the expenses of 

 the reunion. It was felt by all present that 

 Holland had done in the most graceful way 

 a noble piece of work towards the promotion 

 and restoration of that international friendship 

 of science which is of such vital importance for 

 the world. F. G. D. 



