Sept. 27, 1888] 



NATURE 



527 



them. We do not know whether any further consignments ar 

 on their way from the district where Mr. Jameson was stationed 

 for many months with the late Major Barttelot. He described 

 the country as a disappointing locality for the collector, the 

 few birds obtained by him being merely the ordinary Congo 

 species. 



We regret also to have to record the death of Mr. T. II. 

 Potts, a well-known New Zealand ornithologist. Mr. Potts's 

 name has been connected wiih the natural history of New 

 Zealand for a number of years, and his observations on the 

 nesting and life-history of the birds of his native country are 

 among the most interesting contributions to the Transactions of 

 the New Zealand Institute. 



We have received a communication from Herr Gamel. of 

 Copenhagen, the equipper of the Norwegian Expedition to 

 Greenland, in which he informs us that if the undertaking has 

 been successfully accomplished the members of the Expedition 

 should be on board the sailing-ship Pern, which was to leave 

 Disco Bay on September 16, and is due in Copenhagen in the 

 middle of October. If not on board this vessel, the Expedition 

 will have to remain in Greenland until next spring, as this is the 

 last ship leaving, and no news will be obtainable from Greenland 

 till then. 



We learn from the Scotsman that the fishery cruiser H.M.S. 

 /(7^'rt/ lately left Granton on a scientific expedition, which will 

 include a cruise of several weeks in the North Sea and a visit to 

 the Baltic. The chief object in view is to collect data likely to 

 throw more light on various questions which, when solved, will 

 admit of a better understanding of the movements of the edible 

 fishes and of the myriads of minute organisms on which they 

 feed. The Expedition is under the direction of Dr. John Gibson, 

 of the University of Edinburgh Chemical Laboratory, who is 

 accompanied by Dr. Hunter Stewart and Mr. Maitland Gibson, 

 also from the University of Edinburgh. 



Many students of science will regret to learn that the 

 Naturforscher has ceased to appear. The last number is dated 

 September 23. 



Preparations have been made for effecting the proposed 

 connection between the Observatory of Paris and Greenwich. 

 It is expected that this will lead in the end to the acceptance of 

 the Greenwich meridian by French astronomers. 



The General Omnibus Company in Paris has introduced into 

 its service the electricity supplied by the Electric Storage 

 Company. The carriages run from the Arc de Triomphe to 

 Courbevoie, a distance of about two miles. Each of the two 

 fore-wheels is put into rotation by a separate dynamo, over 

 which the driver exerts control. The velocity is somewhat 

 greater than that obtained with horses. 



Three new sulpho- chlorides of mercury have been isolated 

 by Drs. Poleck and Goercki, of Breslau. Every student of 

 chemical analysis is familiar with the peculiar changes of colour 

 which occur when a solution of mercuric chloride is precipitated 

 by sulphuretted hydrogen gas ; how that the precipitate at first 

 is perfectly white, shortly passes to a yellow, and then rapidly 

 darkens, becoming orange, brownish-red, and finally, when 

 excess of the gas has been led through the solution, perfectly 

 black. The white compound first formed was shown so long ago 

 as 1828 by Rose to consist of a sulpho-cbloride of the composi- 

 tion 2lIgS . HgCl 2 ; but the further changes appear never to have 

 been hitherto thoroughly investigated. The Breslau chemists, 

 after fully confirming the composition of the white substance, 

 now show that the darkening is due to the formation of suc- 

 cessive higher sulpho-chlorides, 3HgS . HgCl 2 , 4HgS . HgCl 2 , j 



5HgS . HgCl 2 ; the final product being, of course, the sulphide 

 of mercury, HgS, itself. This has long been supposed to be 

 the case, and it is very satisfactory to have these various sulpho- 

 chlorides at last isolated. It may readily be .een, however, that 

 by simply passing the current of sulphuretted hjdrogen until the 

 precipitate became of any particular tint, one would never be 

 able to isolate these higher compounds, the mixture becoming 

 more complicated every minute. The method adopted, after 

 many fruitless attempts, consisted in completely precipitating in 

 various experiments quantities of mercuric chloride correspond- 

 ing to three, four, and five molecules respectively ; the precipitates 

 were in each case tr nsleued to a ila>k fitted with inverted 

 condenser, and digested for some time with a fresh quantity of 

 the chloride corresponding to another molecule. The first 

 product, 3lIgS . HgClo, possessed a brownish col ur, and the two 

 higher ones more and more nearly approximated to the black of 

 the pure sulphide of mercury. In each case the filtrate w as 

 found to be free from quicksilver and chlorine, proving that the 

 extra molecule of the chloride had in each case combined, and 

 analysis showed that the precipitates really possessed the com- 

 positions above indicated. These sulpho-ch'.orides, moreover, 

 are very stable ; they are almost perfectly insoluble in water, 

 and may be digested with water in sealed tubes at 200 C. 

 without undergoing any change. They are also insoluble in 

 both hydrochloric and nitric acids, but dissolve in the mixture of 

 the two known as aqua regia. They were finally shown to be 

 distinct chemical compounds, and no mere mechanical mixtures 

 of sulphide and chloride, by the peculiar action of potassium 

 iodide upon them. It may therefore be considered that the 

 question of the action of sulphuretted hydrogen upon mercuric 

 chloride has now been definitely settled. 



Prof. H. A. Hazen, of the Signal Service, Washington, has 

 compiled a "Hand-book of Meteorological Tables," containing 

 in a convenient form all the reductions needed for current work, 

 omitting those not now generally used, such as Reaumur tem- 

 peratures, &c. Several of the tables are new, or re-computed 

 in their present form after some years' experience of the author 

 in their use. The table for reduction of barometrical observations 

 to sea-level has been extended to 8000 feet. Among the useful 

 additions we may mention formulae and tables for the determina- 

 tion of mean wind direction, and for the conversion of wind 

 velocities from miles per hour to metres per second, and vice 

 versa. The latest determination of the metre is used in all 

 linear tables. 



On the night of September 5 a brilliant meteor was seen at 

 Bolmen, in Smaland, in Sweden. It first went in a straight 

 line from east to west, when it suddenly altered its course, falling 

 to the earth with a dull report. Its colour was bluish-white. 



Snow and frost are reported from several parts of Sweden, 

 whilst flocks of birds have been seen migrating southwards. 



The preservation of the eider on the south coast of Sweden 

 has had the most beneficial results, considerable flocks of these 

 birds being now often seen. 



Two runic stones have been discovered at Sorunda, in Sweden. 



The Swedish Consul at Eskefjord, in Iceland, writing at the 

 end of August, states that although the fjord was free from ice 

 there were still large masses of drift-ice along the east and north 

 coasts, which were practically unapproachable for vessels. There 

 was also much drift-ice in Denmark Sound. The cod and 

 herring fisheries had been good. 



A Norwegian naturalist, Herr L. Ucherman, draws atten- 

 tion to the peculiarly green waters of certain rivers in Norway, 

 emanating from those snow-fields which never melt, and describes 

 the colour as due to certain green Algoe on old snow. In support 

 of this he mentions that, when walking acrcss old snow in the 



