Nov. i6, 1876] NATURE 



undertaking cannot fail to be a success, owing to its incalculable ' 

 importance with reference to the commerce of Amsterdam. 



The following experiment has recently been employed by M 

 Merget to demonstrate the phenomena of gas-synthesis in plants : 

 Two glass cylindrical vessels of 300 cc capacity are placed with 

 their open ends in a large vessel of water. The one is filled with 

 hydrogen, the other with oxygen, their interiors are brought 

 into communication by means of a branch which is long enough 

 to reach from one end to the other. The level of the water is 

 1 gradually to rise in each cylinder, and both gases finally 

 ;>pear, without, however (.as other experiments show), con- 

 densation or displacement being produced. At the beginning of 

 the experiment there is nearly equality in the volumes which 

 disappear, since a part of the oxygen serves to form carbonic 

 acid ; but^ in proportion as the water level rises in the two 

 cylinders, and the projecting parts of the branch become shorter, 

 the disappearing volume of hydrogen becomes more and more 

 nearly double that of the oxygen. If a similar experiment be 

 made with hydrogen and nitrogen in the two vessels, the dis- 

 appearing volume of the gas is to that of the latter as three to 

 one. Operating with hydrogen and carbonic oxide, both gases 

 always disappear, but in very variable proportions. The most 

 common was one volume hydrogen to one volume carbonic 

 oxide, but the ratios of 4 : I and 5 : I were also sometimes met 

 with. M. Merget finds in these variations the indication of a 

 formation of hydrates of carbon, and of various carburets of 

 hydrogen. 



It is pretty generally supposed that crystallised nitroglycerine 

 is considerably more sensitive to shocks and blows than the 

 liquid substance, though there is nowhere evidence of this ; and 

 not only is practical experience against it, but from the theo- 

 retical standpoint it seems very improbable, for by reason of the 

 positive melting heat of crystallised nitroglycerine, 'a'considerable 

 amount of heat must be employed to change its aggregate state 

 before an explosion can occur. For decision of this question 

 M. Beckerhinn (of the Vienna Academy) recently used a fall- ma- 

 chine furnished with a block of wrought iron 2 "130 kilogrammes 

 in weight, having at its lower end a hardened steel point of 

 7 "068 sq. mm. A flat anvil of Bessemer steel was employed as 

 support for the nitroglycerine, which was placed on it in a thin 

 layer, and the weight dropped upon it from different heights. It 

 was found that the mean height of fall with which explosion of 

 the liquid occurred was 078 metres, whereas the frozen nitro- 

 glycerine did not explode till a fall-height of 2*13 m. was 

 reached, showing that the ^frozen substance is considerably less 

 sensitive to impact. M. Beckerhinn has determined some con- 

 stants of the solid material. The average melting heat (from 

 three experiments) appeared to be 33' 54 heat-units. The den- 

 sity was found = 1*735 C^^^ determinations were made at a 

 temperature of + lo" C, which is near the melting-point of 

 nitroglycerine) ; that cf the liquid material was i "599, whence 

 it appears that in crystallising of nitroglycerine there is a con- 

 traction of about TfVj of the original volume. 



Among the various works presented at the last Congress of 

 Orientalists we notice a very useful catalogue, " Bibliographia 

 Caucasica ; and Transcaucasica," by M, Miansarofif, the first 

 volume of which recently appeared in St. Petersburg. It is the 

 result of fifteen years' labour by the author and of careful research 

 pursued by him in the chief libraries of Russia, Germany, Italy, 

 and Turkey. The work is divided into three parts, devoted 

 respectively to the Earth, to Man, and to the Mutual Influences 

 of Nature and Man. The first two form the first volume (800 pages' 

 in 4to), which contains more than 5,000 titles of books and smaller 

 papers on the Caucasus and Transcaucasus which have appeared 

 in Europe and Asia since A.D. 1565. They are systematically 

 arranged under the heads of geodesy, cartography, physical 



71 



geography and geographical descriptions of localitie.<;, geology, 

 botany and zoology, mineral springs, climate, medicine, &c. 

 Whatever be the imperfections of this work, or of the classifica- 

 tion adopted in it, it will nevertheless prove most useful for all 

 engaged in the study of Caucasus. 



JDr. King's report of the Royal Botanical Gardens, Calcutta, 

 for the year 1875-76 has jiwt reached us. In the acclimatisation 

 of valuable economic plants in India, the Calcutta reports have 

 become of late years the official record, and the present report 

 by no means lacks interest on this score, though it is unsatis- 

 factory to find that Dr. King's opinion is still against the possi- 

 bility of either india-rubber or vanilla becoming staple products 

 of Bengal. With regard to rubber plants both of the Para and 

 Madagascar kinds, he says that during the year it has become 

 more apparent than ever, that neither of these valuable plants 

 can be grown for commercial purposes in the climate of Bengal. 

 In the gardens as well as in the warm tropical valleys of the 

 Sikkim Himalayas both kinds failed. Dr. King suggests that a 

 suitable home may be found for them further north than Tenaa- 

 serim, Ceylon, or perhaps Malabar. Vanilla, of which a number 

 of plants were put out in the garden under shading similar to 

 that used for protecting the pepper plants, has not made satis- 

 factory growth, which it is suggested may have been due to over- 

 shading, and a further experiment has been made by planting 

 many of them under the shade of mango trees. The finest old 

 vanilla plants in the garden are described as growing against a 

 north wall ; this year one of these plants was laden with pods, but 

 an unusually high temperature caused these to drop prematurely. 

 A better report is given of the ipecacuanha ; numbers of plants 

 have been sent from Calcutta to Ceylon, t« the Neilgherries and 

 to Burmah, and the quality of those grown in India is said to be 

 equal to the best native Brazilian growth. A good deal of atten- 

 tion has been directed lately to the bamboo as a source of paper- 

 making material, and it has been thought that it might be 

 cultivated with profit in India for this special purpose, the 

 young tender shoots being reduced to a rough kind of paper- 

 stock for convenience for transmission to England. Dr. 

 King points out that if the old stem would answer the purpose 

 there is plenty of material in India, and a large revenue would 

 accrue, ' but the young shoots are only produced at a certain 

 season ; nevertheless, experiments are being made with a view 

 to utilise the bamboo for this purpose. In the distribution of 

 plants and seeds, we learn that no less than 23,106 plants, and 

 6,343 parcels of seeds, were sent out during the year. It is 

 satisfactory to know that amongst Dr. King's other multi- 

 tudinous duties he has found time to prepare a " Manual of Cin- 

 chona Cultivation," and to edit other works on Indian botany. 

 We also learn that Mr. Kurz's "Forest Flora of Burmah " is 

 passing through the press. 



Part 3 of vol. i. of the Proceedings of the West London 

 Scientific Association has been published, and contains several 

 interesting papers and accounts of excursions. 



The October part of the Journal of the Franklin Institute 

 contains an interesting history of the steam-engine in America. 



Messrs. Williams and Norgate send us the following 

 German scientific works :—"BUder aus Aquarium," by Dr. 

 Hess, of Hanover ; and " Grundriss der Zoologie," by Dr. 

 I Gustav von Hayek. 



I The additions to the Zoological Society's Gardens during the 

 \ past week include two Esquimaux dogs ( C</«w /j/«//Mm) from 

 \ the Arctic region, presented by Capt. Allen Young, S. S. Fan- 

 ' dora; four Viscachas {Lagostonius trkhoda/:tylus) from Buenos 

 \ KYCt%, presented by Mr. C. F. Woodgate ; two Banded Ichneu- 

 I mons {Herpestes fasciatus) from West Africa, presented by Mr. 

 \ W. N. Bakewell; three Chirping Squirrels {'fnmias shiatits) 



