2/6 



NA TURE 



[January i8, 1S94 



disulphide were placed in a flask arranged over a water bath. 

 A large globe had been previously sealed on to the neck of the 

 llas-k, through tubuli in which the carbon electrodes were in- 

 serted. To a third tubulus of the globe an upward condenser 

 was fitted, the interior lube of which was finally bent down- 

 wards to serve as a gas delivery tube. The water bath was 

 then heated and the carbon disulphide maintained in rapid 

 o'lallition, the electrodes were approached until the powerful 

 cuirent from accumulators was transmitted, and then withdrawn 

 so as to generate the arc. The electric arc in carbon disulphide 

 vapour under these conditions is a remarkable phenomenon ; 

 it is seamed with a datk band passing along its centre from 

 pole to pole, and the brightest spots of the incandescent terminals 

 are ji'st where the band appears to touch them. The carbon 

 diculphide was kept boiling and the arc passing for a couple of 

 hours, during which the globe was filled with the vapour, which 

 condensed in the condenser, and fell back into the flask. The 

 interior of the apparatus soon commenced to blacken with liber- 

 ated carbon, which collected upon the surface of the liqui', and 

 an extraordinaiily strong tear-exciting odour soon made itself 

 eviderit in the neighbourhood of the apparatus. At the conclu- 

 sion of the experiment the residual liquid was cheiryred in 

 colour, and was transferred to a closed vessel containing copper 

 turnings in order to remove the free sulphur present. After 

 being thus left for a week it was filtered, and the carbon disulphide 

 evaporated at a low temperature in a current of dried air, in 

 order, if possible, to isolate the substance endowed with the 

 powejful odour. Eventually a few cubic centimetres of a deep 

 red liquid, the new sulphide of carbon, were left, «hich possessed 

 the odour in greater intc i sity, a trace of the vapour producing a 

 copious flow of tears, accompanied by violent and persistent 

 catarrh of the eyes and mucous membrame. A drop of the 

 liquid, moreover, at once blackened the skin. 



The specific gravity of this liquid is I '2739, so that it sinks 

 under water, with which it does not mix. When heated it 

 polymerises into a hard black substance. If the rise of tem- 

 perature is gradual the change occurs quietly, but when rapidly 

 heated to 100-120' the polymerisation takes place with ex- 

 plosive foice, the interior of the vessel being covered with pro- 

 jected deposits of the black substance. Analyses both of the 

 liquid and of the black solid indicate the same empirical formula, 

 C3S.2, and molecular weight determinations of the liquid, dis- 

 solved in benzene, by Raoult's method, agree closely with the 

 molecular weight corresponding to that formula. The liquid 

 can be partially distilled at 60"" in vacuo, a small portion, how- 

 ever, always polymerising. The liquid, moreover, spontaneously 

 changes in a few weeks in;o the more stable black solid modi- 

 fication. . The soIu;ions of the liquid in organic solvents likewise 

 slowly deposit the black form. 



The liquid readily ignites, burning with a luminous flame, and 

 forming dioxides of carbon and sulphur. Caustic alkalies dis- 

 solve if, forming dark coloured solutions from which dilute acids 

 precipitate the polymerised black compound. With alcoholic 

 potash the action is very violent. A drop of concentrated sul- 

 phuric acid causes instant passage to the black form accompanied 

 by a hissing noise. Nitric acid provokes an explosion and 

 ignition, but 70 per cent, acid dissolves it completely and 

 quietly. 



The black polymeric modification is readily soluble in caustic 

 alkalies, but acids reprecipitate it unchanged. When heated it 

 undergoes a remarkable change, sulphur subliming, and a gas, \ 

 inflammable and containing sulphur, but not carbon disulphide, 

 is liberated, the nature of which is reserved for a further com- ! 

 municati&n. 



The liquid sulphide combines readily with six atoms of 

 bromine, with evolution of heat. The substance is readily 

 isolated when bromine is dropped into a solution of CsS., in 

 chloroform, as it is insoluble in that solvent. Strangely enough 

 this comj ound, CjS.jBrg, is endowed with a pleasant aromatic 

 odour, two substances of frightful odours thus uniting to form an 

 agreeably odoriferous compound, a striking example of the efifect 

 of chemical combination. A. E. Tuttox. 



DR. GREGORYS JOURNEY TO MT. KENIA. 



AT the meeting of the Royal Geographical Society on Mon- 

 day evening, Dr. J. \V. Gregory read a 1 aper, of which 

 the following is a lull abstract : — 



It has long been known that the lakes of Equatorial Africa 

 are developed on two types, first those which have low shores 



' and are rounded in shape, and second those which have high, 

 steep shores and are long and narrow. The lakes of the latter 

 group, moreover, are distributed on a definite plan, occurring at 

 intervals along lines of depression across the country. The 

 chief of these runs from Lake Nyasa through a large series of 

 lakes, including Natron, Nawasha, Baringo and Basso Narok 

 (Lake Rudolf) ; from the last of these the line of depression 

 runs through Abyssinia into the Red Sea, which continues 

 the same type of geographical structure for 18" to the north ; 

 thence it can be followed up the Gulf of Akaba to the 

 Dead Sea and Jordan Valley. It seems not unlikely that the 

 whole of this great line is due to one common earth movement 

 of no very great age, for the traditions of the natives around 

 Tanganyika, of the Somalis and Arabs, and of the destruction 

 of Sodom and Gomorrah may have reference to it. It «as the 

 interest which these problems excited that led to Dr. Gregory's 

 desire to visit the district, as he was recently enabled to do, by 

 the permission of the Trustees of the British Museum. He 

 started with a large expedition, intended to explore this "Rift 

 Valley" in the neighbourhood of Lake Rudolf, which landed at 

 Lamu, and thence started up the Tana Valley, where it unfortu- 

 nately collapsed. On his return to Mombasa Dr. Gregory himself 

 ^ organised a small caravan of forty Zanzibaris, and travelled to 

 the highest part of the " Rift Valley" between Nawasha and 

 Baringo, examining its structure and natural history. The most 

 risky part of the journey was crossing ihehigh plateau of LeiUipia, 

 which has only twice befcre been traversed, by Teleki and 

 Hulinel in 1887, and by the German Emin Relief Expedition 

 under Dr. Peters in 18S9-1890. Mr. Joseph Thomson reached 

 its western side, but had to abandon his camp and escape under 

 cover of night. The expedition crossed Leikipia by 

 a new route, and traversing the plateau which 

 is marked as the site of the " Aberdare Mountain"^,'' reached 

 Northern Kikuyu without trouble, except for want of food. 

 The natives at first refused to sell any, as some white men who 

 had visited a neighbouring distiict had seized food without pay- 

 ment, shot the elders, and carried off the young men as porters. 

 After much " shauri " the natives were satisfied as to the peace- 

 ful olject of the expedition, the right of blood-brotherhood was 

 celebrated, and food obtained. The party then turned noith, 

 to the western foot of Mount Kenia. Most of the men were 

 left in the camp while Dr. Gregory and twelve men started for 

 the central peak. Three days were spent cutting away through the 

 dense forest and bamboo jungle on the lower slope. Owing to the 

 damp, mist, and cold, this work was very severe on the Zanzibaris. 

 On the four;h day they emerged on to the Alpine pasturages, 

 only to be caught in a furious blizzard of snow and hail, which 

 necessitated camping for the night on a frozen peat bog. Next 

 day a tent was carried higher up, as a base for reconnoitring 

 excursions. The most important of the peaks on the south 

 slope was ascended, and named Mount Hohnel, after the Aus- 

 trian explorer. Five glaciers and eight lakes were discovered, 

 as well as an interesting flora and fauna. A small shelter-tent 

 was taken to near the end of the largest glacier, in readiness for 

 an ascent of the central peak. A snow-slip during a severe storm 

 in the night nearly buiied this, and did cover all the food. The 

 ascent had therefore to be attempted after a night's exposure to a 

 severe storm, and without food. The main glacier, which was 

 named after the late Prof. Carvtll Lewis, was explored, and 

 the nh'c field at its head crossed to the main south arete. After 

 ascending this for some distance it became badly corniced, tii£ . 

 risks of further progress were too serious to be encountered 

 alone, and after reaching the height of a little over 17,000 feet 

 it was necessary to return. In a subsequent attempt on the 

 west aiite, Dr. Gregory was caught in a severe snowstorm, which 

 rendered the route followed in the ascent impas;able, and might 

 have entailed serious consequences. lie was then recalled to 

 attend to his men, many of whom were suftering severely from 

 the cold and altitude, and an immediate descent to Leikipia was 

 necessary ; he had, however, achieved the five purposes for 

 which he visited the mountain. 



During the return to the coast much new ground was covered 

 with some interesting topographical results ; but except for 

 securing a passage across Kikuyu, by curing the chief of tooth- 

 ache, this part of the journey presented little of general 

 interest. 



In conclusion, some of the scientific results of the expedition 

 were summarised, though it was said to be too early to do this 

 properly. Among the more interesting results was the dis- 

 covery of the former greater extension of the glaciers of Mount 



NO. 1264, VOL. 49] 



