40 



NA TURE 



[May 



89: 



green fruit from (say) Sydney to London, and to solve the 

 chemical problems attaching to the attempt to utilize the cool 

 chambers of swift steam-ships in such a way as to preserve the 

 appearance and flavour of so perishable a commodity as fruit 

 through the unavoidable space of time and varying latitudes of 

 the journey. Mr. Ward is of opinion that there are sound 

 reasons for expecting that " these problems will be solved and 

 that the market will be captured." 



The Echinoderm fauna of Kingston Harbour, Jamaica, seems 

 to be remarkably numerous and varied. Mr. George W. Field, 

 who has been investigating it, contributes some notes on the 

 subject to the April number of the "Johns Hopkins University 

 Circulars." About twenty-eight species of Echinoderms were 

 found in Kingston Harbour and about the cays at its mouth, 

 and a longer residence and dredging in the deeper waters would 

 probably, Mr. Field thinks, have increased the number con- 

 siderably. The difficulties of dredging were very considerable, 

 arising in part from the nature of the bottom, from the 

 unmanageableness of the boat, and chiefly from the wind. 

 There always seemed to be a perfect calm or a gale ; the calm 

 periods between exceedingly short. However, considerable 

 dredging was done by various members of his party. The 

 surface tow-net showed a wonderful richness of the larval 

 Echinoderms in the pelagic fauna, chiefly however, during their 

 stay, confined to Ophiurid, Echinid, and Spatangid plutei, the 

 relative abundance being in the order named. During the 

 month of June they were abundant, and in early July they were 

 extremely numerous. They were found in greatest numbers in 

 tows made about sunrise. In the evening towing they were 

 invariably absent. These larvae, says Mr. Field, appear to ccme 

 to and remain at the surface from midnight until about sunrise ; 

 after that to gradually disappear until three hiurs after sunrise, 

 when they are rarely found at the surface. Their appearance 

 seemed to be little or not at all influenced by the tide, but did 

 depend very much upon the quantity of flood water poured into 

 the harbour by the various rivers. In its general aspect the 

 Echinoderm fauna shows no very considerable variation from 

 that of the Bahamas and Southern Florida, though apparently 

 richer in species and in individuals. 



According to an official report published in the Deutsches 

 Kolanialblatt for April, the Germans have every reason to be 

 satisfied with the way in which the resources of Cameroon are 

 being developed. The industry and trade of the colony are said 

 to be in a flourishing condition. The chief products are palm 

 oil and palm kernels. There are many elephants in the territory, 

 and ivory is still exported. Caoutchouc is also obtained in con- 

 siderable quantities, and ebony fetches good prices. In 1891 

 there were in Cameroon 166 Europeans, of whom 10 were 

 women. There were 109 Germans and 31 Englishmen. 

 The exact number of natives is not yet known, but it is calcu- 

 lated that there are 20,000 Dualla on the Cameroon river, 

 25,000 Bakwiri in the Cameroon Highlands^ and 20,000 

 Bamboko towards the west of the hilly district. 



A VALUABLE paper presenting a revision of the American 

 species of Rumex occurring north of Mexico, by William 

 Trelease, appears in the third annual report of the Missouri 

 Botanical Gardens, and has also been issued separately. 

 Rumex is a genus which has beer held to include from 100 to 

 about 130 species, the greater part of which belong to the 

 north temperate region of both continents. " Of the twenty- 

 one species," says Mr. Trelease, "recognized by me as 

 occurring within our flora, eleven were characterized and 

 named by Linnreus in the first edition of the ' Species Plan- 

 tarum,' and only five have been named by American botanists." 

 The biological interest of the genus arises chiefly, as he points 

 out, from the protective acidity of the sorrels and some docks, 

 NO. I I 76, VOL. 46] 



and the occurrence of tannin and a bitter principle in others ; 

 their protandry and exclusive adaptation to wind pollination ; 

 and the adaptation of the greater number of species to wind 

 dissemination, by the enlargement of the inner segments of the 

 perianth during ripening, although some of those with fimbriate 

 valves may profit by attachment to animals. 



In the latest instalment of the Proceedings of the Academy 

 of Natural Sciences, Philadelphia, Messrs. H. Skinner and 

 L. W. Mengel give an account of some of the insects taken by 

 the expedition which the Academy sent to Greenland in 1891. 

 The insects captured were divided among the diff"erent orders as 

 follows :— Hymenopiera 25 specimens, Coleoptera 4 specimens,- 

 Lepidoptera Rhopalacera 143 specimens, and Heterocera 143. 

 They were captured by Mr. L. W. Mengel, entomologist to 

 the expedition, and Dr. W. E. Hughes, ornithologist. The 

 specimens are all from the West Coast, and were taken at three 

 principal localities, McCormick Bay, Herbert Island, and Disco. 



Acetyl FLUORiDEjCHjCOF, has been prepared by M.Maurice 

 Meslans, and is dest:ribed by him in the current number of the 

 Cowptcs rendtis. As was to be exptcied, it is a substance con - 

 siderably more volatile than acetyl chloride. Its boiling-point 

 is I9°'5, very near that of hydrofluoric acid itself, and hence 

 upon a warm day it takes the form of a gas, while at tem- 

 peratures below 19° '5 it assumes the liquid state. It has been 

 prepared by M. Meslans by causing various inorganic fluorides 

 to react upon acetyl chloride. Tnus when silver fluoride and 

 acetyl chloride are heated together in a sealed tube to 260", a 

 small quantity of acetyl fluoride is formed. The acetyl chloride, 

 however, is much more completely converted to fluoride when 

 it is passed in the state of vapour through a long silver tube 

 filled with dry silver fluoride and heated to 300°. Upon allow- 

 ing the issuing vapour to pass into a strongly cooled receiver, 

 acet)l fluoride condenses in the liquid form. Another mode 

 of preparation consists in allowing arsenic fluoride to fall drop 

 by drop upon acetyl chloride contained in a copper vessel, when 

 energetic action at once occurs in the cold. The exit tube is 

 attached to a spiral of leaden tubing, arranged as an inverted 

 condenser, in order to retain either of the liquid reacting sub- 

 stances, and the last traces of acetyl chloride are removed by 

 subsequently allowing the escaping vapour to pass through a 

 copper U-tube filled with fragments of silver fluoride and heated 

 in a bath of nitrates to 300°. The acetyl fluoride may then be 

 condensed in a strongly cooled receiver. Instead of arsenic 

 fluoride the solid irifluoride of antimony may be employed, and 

 the operation performed in a glass flask, an ordinary inverted 

 glass condenser being used to retain any escaping acetyl 

 chloride. By far the most advantageous mode of preparation, 

 however, consists in reacting with acetyl chloride upon zinc 

 fluoride. One hundred grams of zinc fluoride are introduced in 

 successive portions of ten grams each into a strong glass flask 

 cooled by a freezing mixture and containing a hundred and 

 fifty grams of acetyl chloride. The flask is then sealed, warmed 

 to 40°, and again cooled. It is subsequently opened, while 

 surrounded by the freezing mixture, and placed in connection 

 with a leaden worm whose extremity passes down into a second 

 flask surrounded by ice and containing a little dry zinc fluoride. 

 The acetyl fluoride is then distilled over into the second flask, 

 and upon redistillation over the zinc fluoride contained in the 

 flask it is obtained in an almost pure condition. The liquid 

 may be preserved unchanged in a dry glass vessel, but if moisture 

 obtains access the gla5s is rapidly attacked. If the vessel con- 

 taining the liquid is placed in connection with a tube standing 

 over mercury, and the liquid warmed by holding the vessel in 

 the hand, the new fluoride maybe collected in the gaseous state, 

 and preserved as a gas, provided the temperature of the room 

 is superior to 19" '5. Both the liquid and the gas are colourless. 



