142 



NATURE 



[Z^^r. 8, 1887 



As to the plateau in the north of the Khangai Mountains, it 

 is covered with rich meadows, while the slopes of the hills are 

 clothed with forests of larch ; the Siberian cedar-tree also 

 makes its appearance. In the lower valleys the Mongols carry 

 on some agriculture. 



The above account is followed by an ethnographical sketch 

 of the Ordos-Mongols and the Daldas. 



The results obtained by the expedition are very important. A 

 survey has been made of a stretch of no less than 4400 miles. 

 Latitudes and longitudes have been determined at sixty-nine 

 places. Two hundred photographs, 700 specimens of mammals 

 and birds, a bulky herbarium, and rich collections of lizards, 

 insects, mollusks, and rocks have been brought in. M. Bere- 

 zovsky still remains in the region he has become so fond of, 

 and he wrote last February, from Hoi-siang, that his journeys 

 about Si-ning and Tai-tchan have enriched his collection with 

 500 more specimens of birds, jome of which are very interesting. 



P. A. K. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, November 17. — "Specificlnductive Capacity." 

 By J. Hopkinson, M.A., D.Sc, F.R.S. 



Colza Oil. — This oil has been found not to insulate sufficiently 

 well for a test by the method of my former paper. Most 

 samples, however, were sufficiently insulating for the present 

 method. Seven samples were tested with the following mean 

 results : — 



No. I. This oil was kindly procured direct from Italy for 

 these experiments by Mr. J. C. Field, and was tested as supplied 

 to me — 



K = 3 10. 



No. 2 was purchased from Mr. Sugg, and tested as supplied — 



K = 3-14. 

 No. 3 was purchased from Messrs. Griffin, and was dried over 

 anhydrous copper sulphate — 



K = 3-23. 



No. 4 was refined rape oil purchased from Messrs. Pinchin and 

 Johnson, and tested as supplied — 



K = 3 -08. 



No. 5 was the same oil as No. 4, but dried over anhydrous 

 copper sulphate — 



K =: 3 07. 



No. 6 was unrefined rape purchased from Messrs. Pinchin and 

 Johnson, and tested as supplied, the insulation beipg bad, but 

 still not so bad as to prevent testing — 



K = 3-12. 



No, 7. The same oil dried over sulphate of copper — 



K ^ 3-09. 



Omitting No. 3, which I cannot indeed say of my own know" 

 ledge was pure colza oil at all, we may, I think, conclude that 

 the specificlnductive capacity of colza oil lies between 3*07 and 



3'i4. 



Prof. Quincke gives 2*385 for the method of attraction 

 between the plates of a condenser, 3 "296 for the method of 

 lateral compression of a bubble of gas. Palaz (Za Lumicre 

 Electrique, vol. xxi. 1886, p. 97) gives 3*027. 



Olive Oil. — The sample was supplied me by Mr. J. C. Field — 



K = 3-15. 



The result I obtained by another method in 1880 was 3'i6. 



Two other oils were supplied to me- by Mr. J. C. Field. 



Arachide. — K = 3'i7. 



Sesame.— Y^ = 3'I7- 



A commercial sample of raw linseed oil gaye K = 3'37. 



Two samples of castor oil were tried : one newly purchased 

 gave K =: 4-82 ; the other had been in the laboratory a long 

 time, and was dried over copper sulphate — 



K = 4-84. 



The result of my eai'lier experiments for castor oil was 478 ; 

 the result obtained subsequently by Cohen and Arons ( W^2«/i?- 

 mann^s Annalen, vol. xxviii. p. 474) is 4'43. Palaz gives 

 4'6io. 



Ether. — This substance as purchased, reputed chemically pure, 

 does not insulate sufficiently well for experiment. I placed a 

 sample, purchased from Hoj^kin and Williams as pure, over quick- 

 lime, and then tested it. At first it insulated fairly well, and 

 gave K = 4'75' I" the course of a very few minutes K = 4'93, 

 the insulation having declined so that observation was 

 doubtful. After the lapse of a few minutes more observations 

 became impossible. Prof. Quincke in his first paper gives 

 4 "623 and 4 660, and 4'394 in his second paper. 



Bisulphide of Carbon. — The sample was purchased from 

 Hopkin and Williams, and tested as it was received — 



K = 2-67. 



Prof. Quincke finds 2 "669 and 2*743 ii^ his first paper, and 

 2 '623 in his second. Palaz gives 2 609. 



Amylcne. — Purchased from Burgoyne and Company — 



K = 2-05. 



The refractive (ju) index for line D is i '3800, 



y? = 1-9044. 



Of the benzol series four were tested : benzol, toluol, xylol, 

 obtained from Hopkin and Williams, cyiiiol from Burgoyne 

 and Company. 



In the following table the first column gives my own results, 

 the second those of Palaz, the third my own determinations of 

 the refractive index for line D at a temperature of I7^'S C. and 

 the fourth the square of the refractive index : — 



Benzol 2*38 2-338 i'5038 2-2614 



Toluol 2-42 2-365 1*4990 2-2470 



Xylol 2-39 — 1-4913 2-2238 



Cymol 2-25 — 1-4918 2-2254 



For benzol Silow found 2-25, and Quincke finds 2-374. 



Linnean Society, November 17. — Prof. St. George Mivart, 



F. R.S., Vice-President, in the chair. — Mr. A. Bennett drew 

 attention to new British plants, viz. (i) Arabis alpina, gathered 

 on the Cuchillin Mountains, Isle of Skye ; (2) Jtiitcus alpina, 

 obtained in Perthshire ; and {^)Juncus tenuis, got near Galloway, 

 Kirkcudbrightshire. — Mr. W. H. Beeby made remarks on Carex 

 caspitosa from Shetland. — Photographs of a branched palm 

 (Borassus Jiahelliformis) was shown for Surgeon-General Bidie, 

 of Madras, and a letter thereon read. The tree is growing near 

 Tanjore, at a village named Paducottah, and is remarkable in 

 being divided into eight branches. — Mr. W. Wilson sent for 

 exhibition branches with ripe berries of Taxus baccata, and its 

 variety hybernica, produced by natural cross-fertilization : these 

 were grown in Central Aberdeenshire. — Mr. T. Christy showed 

 a new species of Strophanthus from the Niger ; it is distinguished 

 by its brown velvety seed and intensely bitter taste. — Mr. D. 

 Morris exhibited the following specimens: (i) a fibre from 

 Vera Cruz, named Broom Root, which examination showed to 

 be the root fibres ol Epicampts macroura, known as " Ravizde 

 Zacaton " by the Mexicans, its yearly value in expert is ;,^6o,ooo ; 

 (2) another Mexican fibre, " Ixtli," much used for nail-brushes, 

 &c. , in Britain, by reason of its short tough fibre, is found by the 

 Kew authorities to be derived from Agave heteracantha. — Mr. J. 



G. Baker showed Lycopodium albidum, a new species from the 

 Andes of Ecuador ; it is allied to Li clavatum, but without chloro- 

 phyll except at the base. He also showed Neobaronia xipho- 

 clades, a new Papilionaceous plant from Madagascar, obtained 

 by the Rev. R. Baron. — A paper was read by Mr. P. Geddes, 

 on certain factors of variation in plants and animals. — Then 

 followed a paper on the Copepoda of Madeira and the Canary 

 Islands, by Mr. I. C. Thompson. In all, sixty- five species were 

 obtained. Of these, six are new to science, and three probably of 

 generic significance. Twenty-three are known in Briiish waters, 

 and of these fourteen belong to the family Harpacticidse. There 

 is a similarity in species in the different islands, but the numbers 

 of each vary greatly. 



Geological Society, November 9. — Prof. J. W. Judd, 

 F. R. S., President, in the chair.^ — The following communications 

 were read: — Note on the so-called " Soapstone " of Fiji, by 

 Henry B. Brady, F.R.S. The Suva depo-it, which has a com- 

 position very similar to that of the volcanic muds at present 

 forming around oceanic islands in the Pacific, is friable and 

 easily disintegrated. The colour ranges from nearly white to 

 dark gray, the mass being usually speckled with minerals of a 

 darker hue. Under the microscope the rock presents the 

 character of a fine siliceous mud with crystals of augite, &c., 



