372 NATURAL SCIENCE. June. 



The Dutch Scientific and Medical Congress. 



The sixth Meeting of the Nederlandsch Natuur en Geneeskundig 

 Congres took place at Delft, on April 22nd, 23rd, and 24th, and afforded 

 two English visitors, who were privileged to be the guests of Prof. 

 Lobry de Bruyn, an opportunity of seeing how well these things are done 

 in Holland, and of carrying away a very pleasant impression of Dutch 

 hospitality. The proceedings opened on Thursday with a reception 

 at the Stads Doelen, and closed on Saturday with a dinner at the 

 same place, from which members and guests adjourned for the 

 further entertainment of tableaux vivants and a social gathering. 

 The " Phcenix," or students' club house, was also generously thrown 

 open for the occasion. The general President was Prof. J. M. 

 Telders, and the five sections were presided over respectively by 

 W. A. van Dorp of Amsterdam, W. Kapteijn of Utrecht, P. P. C. 

 Hoek of Helder, H. Treub of Amsterdam, and K. Martin of 

 Leyden. The sectional meetings were held in the various laboratories 

 and lecture-rooms of the Polytechnic School, in both morning 

 and afternoon. Several of the sections had very attractive pro- 

 grammes ; among the most interesting papers in Section II (Biology) 

 may be mentioned one by Prof. Hubrecht on " Primates and 

 Lemurs," and one by M. C. Dekhuijzen, of Leyden, on methods of 

 investigating the micro-organisms in fresh water. The Section for 

 Physics and Chemistry had an able paper by Col. C. F. Geij van 

 Pittius, on various explosives, and one by H. A. van Ijsselstein on 

 an interesting form of telephone. But the paper which formed 

 the last of the series on Saturday was one so brilliant as almost 

 to throw all others into the shade ; this was a lecture by Prof. 

 M. W. Beijerinck, on luminous bacteria, illustrated by lantern- 

 slides and a really magnificent series of experiments, which received 

 the applause they deserved. Prof. Beijerinck's work in bacteriology 

 is well-known ; he has discovered at least two new species of 

 marine bacteria which cause phosphorescence, and his experiments 

 to show the nature and extent of their luminosity, and the conditions 

 under which they exhibit the phenomenon could hardly be equalled 

 for beauty and interest, and were worthy of a far larger audience 

 than could be accommodated in the lecture-room of the Natuur- 

 kundig Laboratorium. In the intervals between meetings, mem- 

 bers and visitors were given the opportunity of seeing the beautiful 

 porcelain-manufacture, for which Delft has always been famous, a 

 process of etching on glass for decorative purposes, various exhibits 

 of scientific apparatus and other objects, and last, but not least, 

 many places of historic interest, as, for instance, the staircase where 

 William the Silent met his death. The quaint picturesqueness of the 

 old town, with its waterways, and its delightfully fresh and bracing 

 air will make the Delft Congress a pleasant memory to many of the 

 1,000 people who gathered to do it honour. 



