544 



NATURE 



[A/>rt/4, 1889 



The Executive Committee of the International Exhibition of 

 Geographical, Commercial, and Industrial Botany, to be held at 

 Antwerp in 1890, has decided to celebrate on this occasion the 

 three hundredth anniversary of the invention of the microscope. 

 It proposes to organize what it calls a retrospective exhibition of 

 (he microscope, and an exhibition of instruments produced by 

 living makers. Conferences relating to all important questions 

 connected with the microscope will also be held. The Exhibition 

 •ought to be remarkably interesting, and will no doubt be a great 



We are glad to hear that the Congress of the United States 

 has recently provided for the establishment of a Zoological 

 Park in the City of Washington, and has appropriated money 

 for the purchase of a tract of land of not less than one hundred 

 «cres in extent, immediately adjacent to that city. The proposed 

 site for the park is the valley of Rock Creek, a small river 

 emptying into the Potomac at Washington. This is said to be 

 one of the most picturesque sites ever devoted to such a purpose, 

 having several rocky cliflFs of considerable extent, groves of pine, 

 •oak, beech, and other trees, and several little streams running 

 <iown the steep sides of the valley into the river. Part of the 

 land is under cultivation, but much of it is virgin forest, so that 

 •its natural advantages have been preserved by singular good 

 fortune in spite of the neighbourhood of the growing city. 

 Amongst the animals to be kept here will, no doubt, be a herd 

 of the buffalo (Bison americanus), now nearly extinct in the 

 "Western prairies. 



The half-yearly general meeting of the Scottish Meteorological 

 ■Society was held in the hall of the Royal Scottish Society of 

 Arts, Edinburgh, on Monday, April I. Next week we shall 

 give some account of the proceedings. We are glad to learn 

 from the Report of the Council that the application of the 

 Society for a grant from the surplus fund of the Association of 

 •fhe Edinburgh International Exhibition of 1886 has been 

 acceded to, the Association having granted the handsome dona- 

 tion of ;^iooo towards the completion of the Ben Nevis Observa- 

 tory by the establishment of the Low Level Observatory at 

 Fort William. 



A FRIGHTFUL hurricane, which raged for nearly two days, 

 broke over the Samoan Islands on the night of March 16. Of 



■seven foreign war-vessels caught by the hurricane at Apia, only 

 H.M.S. Calliope contrived to make the open sea. The German 



:and American squadrons were destroyed, and many lives lost. 



The meeting of the French Meteorological Society on the 

 5th of March was chiefly occupied by an analysis of the report of 

 the Krakata~o Committee, by M., L. Teisserenc de Bort. The 

 Abbe Maze presented an apparatus for rotating a thermometer 

 fixed in a framework, and intended to take the place of the sling- 

 thermometer in cases in which the latter was inconvenient. The 

 Society has received a circular from the . Minister of Public 

 Instruction, asking for a list of old manuscript observations, 

 with a view to the preparation of a catalogue for publication. 



Vapour-density determinations of bismuth, arsenic, and 

 •thallium have been successfully carried out at extraordinarily 

 high temperatures in the laboratory of the University of 

 Gottingen by Dr. Biltz and Prof. Victor Meyer. The highest 

 temperature hitherto attained in former experiments by Dr. 

 Mensching and Prof. Meyer lay somewhere between 1400° and 

 1500° C. Now, thanks to a suggestion of Prof. Nilson, of 

 Stockholm, means have been found of raising the temperature of 

 the Perrot gas furnace, in which the well-known Victor Meyer 

 porcelain density apparatus was heated, to a white heat of 

 t6so°-i75o°. Hence there are now from 200 to 300 more 

 ■degrees of temperature at which density determinations are 



possible, and it may naturally be expected that substances which 

 were only partially vaporized at 1450° may yield definite re- 

 sults at I7SO^ The temperatures were determined by means of 

 a glazed porcelain air-thermometer, which was decisively proved 

 to be impermeable to the furnace gases. In order to further 

 strengthen that portion of the porcelain apparatus placed in the 

 furnace, it was surrounded by an outer casing of platinum. The 

 volatilizations were effected in atmospheres of nitrogen, all traces 

 of oxygen being rigorously excluded. Bismuth was found in 

 the former experiment to be only partially vaporized at 1450°. 

 At the higher temperatures now available it has been found to 

 be rapidly and completely volatilized, and density determinations 

 have been readily carried out. The values obtained in two ex- 

 periments at r6oo°-i7oo° are ii'gS and io-i2 (air =1). If the 

 bismuth molecule in the gaseous state consists of the normal two 

 atoms, Bij, its vapour-density should be I4'4 ; if it contains only 

 one atom, Bij, the density becomes 7 '2. The values obtained, 

 which are considerably less than that required for the normal 

 molecular condition, show that this condition is impossible, and 

 bismuth therefore resembles mercury, cadmium, and zinc, in con- 

 taining only one atom to the molecule. In the case of arsenic 

 the results agree very well with the assumption of a two-atom 

 molecule, Asj. At 1714° the density found was 5-45 ; and at 

 1736°, 5 '37- As^ requires'5'20. Hence the four-atom molecule 

 of arsenic at lower temperatures becomes dissociated about 1750° 

 into the normal molecule consisting of two atoms. Thallium ap- 

 pears to be at once normal. At 1636° the value obtained was 

 i6-ii ; and at 1728", 14*25. The ordinary molecule Tlj 

 corresponds to 14" 17. The metal, however, is still difficultly 

 vaporizable even at this tremendous temperature. Another very 

 interesting result was obtained in case of cuprous chloride, 

 which even at 1 700° gave densities almost exactly correspond- 

 ing to the formula CujClg. Sulphur, iodine, and mercury also 

 gave results confirming the stability of molecules const sting of 

 two atoms of sulphur and single-atom molecules of iodine and 

 mercury. 



Mr. C. G. Hall, of Dover, sends to the new number of the 

 Entomologist's Monthly Magazine the following note, written by 

 the late moth-collector, Mr. H. J. Harding : — " On a beautiful 

 evening at the end of June 1852, in the locality of Darenth 

 Wood, I had just pinned my first insects taken at sugar, when I 

 heard a strange sound behind me, and, on looking round, ob- 

 served what I thought was a beetle flying round a sallow bush ; 

 when in my net, it again repeated the sound, but what was my 

 surprise upon finding it a Lepidopterous insect. I had now got 

 it between my thumb and finger to give it an entomological 

 pinch, when it again produced the sound ; the deadly pin was 

 now presented, and, with the aid of my lantern, I found it was 

 a common Halias prasinana. But it was a fact new to me : I 

 I had never, during thirty years entomologizing, heard of such 

 a thing before. The sound was as if you passed a pin sharply 

 along three or four teeth of a comb. I suppose it was a love 

 song to charm his lady." 



Recently there have been some valuable "finds " of antiquities 

 belonging to the Iron Age in Norway. At Nottero, on the 

 Christiania Fjord, there were found in a mound some bones, an 

 iron pot with handles, a sword 2 feet 6 inches long, the handle 

 having knobs of a yellow metal, an anvil, and a pair of smith's 

 tongs. The mound was no doubt at on e time situated close to 

 the sea ; it is now some 300 yards inland. At Laurvig a large 

 number of similar articles were discovered in two mounds. 



In a Report, just received, Mr. R. L. Jack, Government 

 Geologist, Queensland, gives a valuable account of the geology 

 of the Russell River, which he lately visited with Mr. Christie 

 Palmerston. They were accompanied by eight "aboriginal 

 boys," and Mr. Jack incidentally presents a vivid description 



