March 20, 1884] 



NA rURE 



489 



the house healthy, learing of infants, prevention of the spread 

 of infectious diseases, preparation of food and kindred subjects, 

 knowledge of which is so much needed in our crowded ne'gh- 

 bourhoods. The questions of poisonous dyes in domestic fabrics, 

 of smoke abatement, of dust collection, and the prevention of 

 cholera have been investigated and reported upon by special 

 committees apjointed for the purpose. The Health Exhibition 

 held by the Society last June was commented upon, and the 

 Secretary stated that more than lOO members had joined the 

 Society during the past year. 



The great interest manifested in the International Health 

 Exhibition is shown by the fact that application has been made, 

 by British exhibitors alone, for space five times as great as that 

 actually at the disposal of the Executive Council. Information 

 has recently been received that the French Government has 

 appointed a Commission ; and Italy — owing in a great measure 

 to the individual exertions of a member of the Executive Council 

 — will, it is hoped, take an active part. A portion of the Educa- 

 tional Section of the Exhibition will be located in the Central 

 Institute of the Cily of London Technical Guilds, the handsome 

 building in course of erection in the Exhibition Road, which has 

 been kindly placed at the disposal of the Executive Council. 

 The Royal Albert Hall with its musical attractions will now 

 form an integral part of the Exhibition ; and the Aquarium, a 

 popular feature of the late Fisheries Exhibition, will continue as 

 an important part of the Health Exhibition. In the Dress Sec- 

 tion the most popular exhibit will probably prove to be a series 

 which is being prepared illustrative of English dress of all ranks 

 of life, from the time of the Conquest to George IV. An Inter- 

 national Congress on Education will be held, and conferences 

 and lectures will conduce to the elucidation of the subjects of the 

 Exhibition. It is also proposed to have a library and reading- 

 room in connection with the Exhibition, which will be open to 

 all visitors, under proper regulations, while the Exhibition is 

 open. The library will consist of books on various subjects 

 comprised in the classification of the Exhibition, both English 

 and foreign. Application has been addressed to foreign and 

 colonial Governments, asking them for copies of reports and 

 statistics on sanitary and educational matters, and a circular is 

 being sent out to authors and publishers requesting them to 

 contribute works of a similar character. 



At a meeting of the Society of Telegraph Enghieers held on 

 the 13th inst., a short paper, "Notes on a Train Lighting Ex- 

 periment," was read by Mr. W. H. Massey of Twyford, who 

 strongly advocated the use of a small engine and dynamo- 

 machine placed on each locomotive for working incandescent 

 lamps, by means of which railway carriages would be much 

 better lighted than at present for less than is paid for gas. An 

 interesting discussion took place, and the meeting was adjourned 

 to the 27th in>t. , when Mr. Massey is expected to reply. 



The March number of Petermann s MUtheilungen contains a 

 letter from Dr. Junker dated Sami, 6J' N. lat., 25° E. long., 

 December S, 1882, in which he gives a brief >tatement of the 

 results of his journeys in the Upper Welle and Bomokandi, with 

 notes on the various tribes that inhabit the region. Dr. Junker 

 did some further exploring work to the south-west of his station 

 in 1883 ; but his numerous cases of collections have been lost 

 in a fire which consumed the building where they were stored. 



The additions to the Zoological Society's Gardens during the 

 past week include a Squirrel Monkey {Chiysolhrix sciurea) from 

 Guiana, pre-enled by Mrs. Dundas ; a Leopard {Felis parjiis) 

 from Africa, presented by Mr. S. Cresswell ; a West Indian 

 Rail (Aramicits cayennensis) from South America, presented by 

 Mrs. Edward Hairby ; a Kestrel ( Tinnitnculits alaudarius), 

 British, preseii'.ed by Mr. F. E. Baum ; a Common Viper 



[Vipc-ra I'erus), British, presented by Mr. W. II. B. Pain; two 

 Mute Swans (Cygims olor), European, four Redshanks [Totanus 

 calidris), British, purchased. 



PHYSICAL NOTES 



Prof. J. H. Poynting has published in the Proceedings of 

 the Birmingham Philosophical Society a note on a method of cal- 

 culating the velocity of propagation of waves of longitudinal and 

 transverse disturbances by the rate of transfer of energy. The 

 paper discusses the two cases by the method originally propounded 

 by Lord Rayleigh. 



We have received from Madame Plateau copies of three 

 postliumous memoirs by her late husband, the lamented Prof. J. 

 Plateau. Their titles are: "Quelques Experiences sur les lames 

 liquides minces (deuxieme note)"; " Siu- I'Observations des 

 Mouvements tres rapides " ; and " Bibliographie analytique des 

 Principaux Phenomenes subjectifs de la Vision." The first of 

 these brochures relates to the preservation of the glyceric fluid, 

 to certain appearances in very thin films, and on the constitution 

 of foam. In the second the writer contrasts four methods : the 

 rotating mirror, the stroboscopic method, the intermittent illu- 

 mination by electric sparks, and the process of multiple instan- 

 taneous photography. The third is a supplement for the years 

 1880-1SS2 to the well-known bibliography compiled by the 

 deceased savant. 



We have also received the first instalrnent of vol. i. of the 

 Bulletin de la Societe Internationale des EUctriciens (January I, 

 1884), containing the laws of the new society, a list of founders, 

 and one of the members already enrolled, now numbering about 

 1200, of whom only a few are Englishmen. 



Prof. Quincke has lately read before the Berlin Academy a 

 paper on the measurement of magnetic forces by hydrostatic 

 pres-ure. He has examined the magnetic inductive capacity, or, 

 as he calls it, the "di-magnetic constant " of a number of liquids, 

 by observing their rise in an open-air manometer when subjected 

 to a field of powerful, but known, intensity, the observed change 

 of pressure iieing proportional to the square of the intensity of 

 the field and to the difference between the magnetic inductive 

 capacity of the substance and that of the air. A number of 

 tables are given, with copious numerical data. The dimagnetic 

 constant of such liquids as ether, alcohol, turpentine, nitric acid, 

 bisulphide of carbon, glycerine, water, &c., showed small nega- 

 tive values ; whilst the values were positive, and in many cases 

 much more considerable for solutions of chloride of iron, chloride 

 of mangane.-.e, sulphate of nickel, and of cobalt, and for solutions 

 of magnetic salts in general. 



A SLIGHT mistake occurred in a note on p. 276, in which 

 Bunsen's estimation that in three years S' 135 cubic centimetres 

 of cirbonic dioxide was absorbed by a square metre of glass was 

 stated as the absorption of one square centimetre. 



THE CHEMICAL WORK OF WOHLER^ 

 fT seems fitting that these walls, which have vibrated in sym- 

 pathy with that brilliant eulogy of Liebig which Prof. Hof- 

 mann pronounced some nine years Ego should hear something of 

 him whose life-long association vviih Liebig has exercised an 

 undying influence on the development of scientific thought. The 

 names of Frederick Wohler and Justus Liebig will be linked 

 together throughout all time. The work which they did in 

 common makes an epoch in the history of chemistry. No truer 

 indication of the singular strength and beauty of their relations 

 could be given than is contained in a letter from Liebig to 

 Wohler, written on the last day of the year 1871. "I cannot 

 let the year pass away," writes Liebig to Wohler, "without 

 giving thee one more sign of my existence, and again expressing 

 my heartfelt wishes for thy welfare and the welfare of those that 

 are dear to thee. We shall not for long be able to send each 

 other New- Years' greetings, yet, when we are dead and moulds r- 

 ing, the ties which have united us in life will stdl hold us to- 

 gether in the memory of men as a not too frequent example of 

 faithful workers who, without envy or jealousy, have zealously 

 laboured in the same field, linked together in the closest friend- 

 ship." 



' A lecture delivered at the Royal Inititutu 

 Febiuary 15, 1SS4, by rrof. Thorpe, F.K.S. 



Friday evening. 



