Feb, 7, 1889] 



NATURE 



35* 



floras, and that the latter penetrates within the forest region in 

 the shape of isolated and well-defined oases ; while a mixed 

 vegetation, containing specie* characteristic of the steppes, in- 

 termingled with representatives of ihe meadows of the forest 

 region, is met with only sporadically on the banks of some 

 rivers, on the southern slopes of some hills, or on the outskirts 

 of the forests. He distinguishes, on the contrary, a vegetation 

 which has its own special characters over very wide tracts — from 

 Astrakhan to Yaroslav — and is met with on tiie banks of the 

 Volga, Kama, and Vyatka, as well as on the banks of the lakes 

 which formerly were connected with the rivers and their old 

 beds. 



The Annuaire du Burcati des Longitudes for 1889 contains 

 the usual astronomical and physical tables, and much useful infor- 

 mation relating to meteorology and other subjects. There is an 

 admirable list of variable stars, with their positions corrected 

 for 1889, and the dates of maxima and minima. The particulars 

 of cometary orbits are brought up to Olbers's comet of 1887. With 

 the exception of the memoirs at the end, however, there is little 

 novelty. M. Tisserand contributes a very useful paper on the 

 measurements of the masses of celestial bodies, including planets, 

 asteroids, satellites, comets, and binary systems ; a better 

 account of the application of the laws of gravitation to this 

 purpose would be difficult to find. Perhaps the most in- 

 teresting paper is that contributed by M. Janssen, on his 

 memorable expedition to Mont Blanc for the purpose of 

 deciding whether certain lines in the solar spectrum are due to 

 oxygen in our air or in the solar atmosphere. The results of 

 the observations made on Mont Blanc showed that these lines 

 were due to our own atmosphere, as they were weaker there 

 than at lower levels. 



We have received the Annuaire de I'Academie Royale de 

 Belgique for 1889, this being the fifty-fifth year of publication. 

 Besides the academical calendar for the year, it contains a general 

 history of the organization and nil particulars relating to each 

 department. It also gives accounts of the Commissions dele- 

 gated to superintend the publication of national biography and 

 history. Details of the prizes and medals at the disposal of the 

 Academy, and the recipients of them from the dates of their 

 institution, are also given. About 340 pages are devoted to 

 biographical notices of deceased members, which are accom- 

 panied by admirable portraits, and full particulars of the works 

 of each. It is interesting and gratifying to note the frequent 

 occurrence of "Leopold II., Roi de Belgique," in connection 

 with the work of the Academy. 



Another important paper is contributed by Prof Emil 

 Fischer and Dr. Tafel to the number of the Bcrichtc just ■ 

 received, upon the syntheses of glucose and mannite. Not only 

 has the method of synthesizing glucose been perfected, and ^ 

 large yields of it obtained, but it has also been shown to ferment 

 with yeast like natural glucose, and also like glucose to yield. 



on reduction with sodium amalgam, the hexhydric alcohol man- 

 nite. The first process by which the synthesis was effected, and 

 which was fully described in Nature, vol. xxxvii. p. 7, con- 

 sisted intreating acrolein dibrom'de with biry ta- water, the 

 sugar left in solution being afterwards precipitated by phenyl 

 hydrazine in the form of a peculiar compound with the latter 

 substance of the composition CjgHj^NjO^. This phenyl hydrazine 

 compound was then reduced with zinc dust and acetic acid, the pro- 

 duct beinga base which, on treatment with nitrous acid, parted wi,h 

 its niMogen, leaving a solution from which glucose was extracted 

 by means of absolute alcohol. This method of obtaining glucose 

 from the phenyl hydrazine compound was both exceptionally 

 difficult in manipulation, and gave a very small yield of the 

 sugar. The Wiirzburg chemists have recently discovered a far 



better process. The finely-powdered phenyl hydrazine com- 

 pound is warmed with concentrated hydrochloric acid, when it 

 dissolves to a clear dark red liquid. On cooling, phenyl 

 hydrazine hydrochloride crystallizes out and is filtered off. 

 The diluted filtrate is neutralized with hydrated lead carbonate, 

 decolorized with animal charcoal, again filtered, and the solution 

 made slightly alkaline with baryta- water. A syrupy substance of the 

 constitution CH.pH. (CHOHJs. CO . COH, which differs from 

 glucose in possessing two atoms of hydrogen less, is at once 

 precipitated in combination with lead. The precipitate is next 

 treated with sulphuric acid and again neutralized with barium 

 carbonate. The filtered solution, at last obtained almost pure, 

 is evaporated in vacuo upon a water-bath, and the syrup 

 extracted with absolute alcohol ; on evaporation of the alcohol, 

 the syrup is left behind in the pure state, and solidifies on cooling 

 to a hard amorphous mass. It is only necessary now to reduce 

 the aqueous solution of this syrup with zinc-dust and acetic acid, 

 when the two additional hydrogen atoms are taken up and 

 glucose formed. The zinc is precipitated from the filtered liquid 

 by sulphuretted hydrogen, and the filtrate evaporated in vacuo 

 upon the water-bath. On extraction of the syrup with absolute 

 alcohol, and subsequent addition of ether, the sugar is precipi- 

 tated in colourless flocculae, which rapidly coalesce into a sweet- 

 tasting syrup of pure glucose. By this method so large a yield 

 has been obtained that fermentation experiments have been 

 possible ; and with beer yeast this artificial glucose is found to- 

 rapidly ferment, evolving abundance of carbonic anhydride at 

 the ordinary temperature. It reduces Fehling's solution, and 

 only differs from natural dextrose and laevulose in being optically 

 inactive, consisting, as it probably does, of a mixture of equal 

 molecules of the right- and left-handed varieties. Further, by 

 action of sodium amalgam, it is readily reduced to a compound 

 of the formula CeHj406, which crystallizes in fine pl.ites and 

 melts at 165° ; in fact, possesses all the properties of the 

 hexhydric alcohol, C6H8(0H)g, mannite. 



The Board of Trade Journal publishes a memoranduja 

 which has been drawn up in the Fisheries Department of the 

 Board of Trade relative to the Sea Fisheries Regulation Act, 

 1888. The memorandum says that the Board of Trade may on 

 the application of any county or borough Council create a sea 

 fisheries district, and define its limits, and provide for the consti- 

 tution of the local committee, which body is to have power \.o 

 make by-laws regulating sea-fishing and oyster-fishing, to 

 impose fines and forfeitures for the breach of such by-laws, and 

 to appoint fishery officers for enforcing the observance of the 

 by-laws within the district. Fishery officers will be empowered 

 to search any vessel or vehicle used in fishing or in conveying 

 fish. 



The Zoological Record for 1887 has just been issued. The 

 editor is Mr. Frank E. Beddard. He explains that the only 

 alteration of importance in the present volume is that authors' 

 names have been printed throughout in capitals. It will be 

 found that this renders clearer the references in the systematic 

 part of the several records. 



We have received the first number of Art and Lileratitre, 

 published by Messrs, Maclure, Macdonald, and Co., Glasgow. It 

 is well printed and illustrated, and the only fault we have to find 

 with the new venture is that the word " Science " is not included 

 in the title. 



The fourth part of Cassell's excellent "New Popular 

 Educator " has been issued. This part, which contains contri- 

 butions to the study of geography, physical geography, physio- 

 logy, astronomy, and other subjects, is accompanied by a map of 

 England, and is well illustra'.ed. 



