Vol. IX. No. 221. 



THE AGRICULTURAL NEWS. 



335 



seedlings in Ceylon, and forms small, circular seini-transparent 

 spots, bordered by a purple-brown line. C'llletotrichnni lievene, 

 Fetch, and <ihn:os.porium livunneum, Fetch, cause the yellow- 

 ing and dropping of the first two leaves of seedlings in Ceylon. 

 Plii/Uostii-lii heveae, Ziniru., and Gloi-osjinriuin e/astirae, Cke. 

 and Mass., also occur in Ceylon and .Java. In the Amazon 

 district, where the tree is native, FJiyllachora Huberi, P.Henn., 

 Dothidelta Ulei, P. Henn., Aposphaeria Ulei, P. Henn., Ophio- 

 Mus heveae, P. Henn., and Parodiella melioloides (Berk, 

 and C.) Wint., occur on Hevea; all are unimportant, with the 

 possible exception of the Ophiobolus. Bernard records Pental- 

 ozzia ixdmaruin from the Dutch East Indies. Colletotrichum 

 Jicus and Colletotrirh'um elasticae occur on the leaves of Ficus 

 elasticii in .lava, the former producing lines of raised dots: the 

 latter, small black-tufted spots. 



The following references to literature dealing with 

 these may be given: Fetch, Ciiciifurs and Agricultural 

 Journal of the Royal Botanic Gaidens, Ceylon, Vol. 

 Ill, p. 280; Agricidtural Bulletin of the Straits and 

 Federated Malay States, Vol. HI, p. 173; P. Hennings, Kn- 

 ti.lilatt des Kiinigl. Botani^chen Garten/: and Museums :« 

 Berlin, Vol. IV, p. 133: Bernard, Bulletin XII, du Departe- 

 ment de I'.Agriculture aux Indes Neerlandaises; Koorders and 

 Zehnter, Bulletin Xo. 3 of the Algemeen Proefstation of Sala- 

 tiga, quoted in the Agricultural Jourrud oj the Straits and 

 Federated Malay States, Vol. V, p. 8. 



Further information on the whole subject will be found in 

 the Agricidtural News, Vols. V, p. 362, and VI, p. 318, in 

 addition to that given in the references already ijuoted. 



This concludes the account of the principal diseases of 

 rublier trees, as far as the lite.ature obtainable at the Head 

 Office of the IJepartment will permit. It is noticeable that 

 very few of them have made their appearance, as yet, in the 

 West Indies, although cacao is extensively cultivated in most 

 of the islands into which rubl)er cultivation has been intro- 

 duced; the cacao diseases, which are for the most part very 

 similar to those found in the East, do not appear to have 

 spread to rul)ber in the West Indies, as they seem to have 

 done in Ceylon and elsewhere. A possible exception to this 

 statement is the fact that a fungus almost exactly similar to, 

 if not identical with, Lasiodiplodia tkeolinnna. Griffon and 

 Maublanc, has been found on Castilloa in Trinidad. It is to 

 be hoped that, if reasonable precautions are taken, this 

 immunity from disease will l>e found to continue. 



THE DIRECT PRODUCTION OF 

 AMMONIA. 



The London Times SappletaerU liir May l!S, l!)iO, 

 contained the following information concerning the 

 niainif'acture of ammonia from its elements — nitrogen 

 and hydrogen. It is of interest, in that it indicates 

 a new way of combining nitrogen for use in manures: — 



In view of the rapid increase in the demand for fixed 

 nitrogen, and the steady diminution of the ('hile .saltpetre 

 deposits, the manufacture of ammonia from its elements, 

 nitrogen and li}drogen, would be of enormous industrial 

 importance, and would be the more advantageous economic- 

 ally, inasmuch as nitrogen and hydrogen can be obtained at 

 a cost which only amounts to a fraction of the market price 

 of ammonia. 



considered impossible from a technical point of view, the 

 inertness of nitrogen at low temperatures, and the slight 

 affinity between that element and hydrogen at high tempera- 

 tures, seeming to exclude any possibility of practical success. 

 Dr. F. Haber, Professor at the Carlsruhe Technical High 

 School, has shown, however, in a series of experiments carried 

 out with the assistance of M. R. Le Rossignol, that the 

 direct combination of the two elements can be realized in 

 such a way as to lend itself to commercial utilization, by the 

 aid of enormous pressures, far exceeding any so far applied for 

 technical purposes in connexion with gas reactions. It is true 

 that, even at a pressure of 200 atmospheres, the combination 

 of the elements is always incomplete, but the ammonia, as it 

 is formed, can be removed by the use of a high-pressure circul- 

 ating system, comprising, in a closed cycle, a reaction vessel, 

 precipitation vessel, and circulating pump. After being 

 liquefied by moderate cooling in the precipitation vessel, the 

 ammonia can be drawn off, the unused amounts of nitrogen 

 and hydrogen remaining in the cycle. An apparatus for 

 laboratory purposes, exhibited by Professor Haber at a recent 

 lecture, can be continuously worked at a pressure of 18-5 

 atmospheres, producing 90 grams of liquid ammonia an hour. 



Extensive experiments on the efficiency of various cata- 

 lysing agents at pressures close to 200 atmospheres have 

 shown osmium to be an excellent substance for the purpose. 

 With a mixture of about three volumes of hydrogen, to one of 

 nitrogen, at a jiressure of 175 atmospheres and a temperature 

 close to bad C, an output of upwards of 8 per cent, of 

 ammonia by volume was readily obtained, by the aid of 

 finely divided osmium. The supply of this element, how- 

 ever, is small, and accordingly some more abundant catalyst 

 was sought for. Uranium, which according to the periodic 

 system, bears a similar relation to the slightly active chrom- 

 ium as osmium does to iron (which has long been known 

 to exert a certain catalytic action), was found to be very 

 suitable. 



The results attained seem to prove the commercial 

 possibilities of the process, and as it is being develojied by 

 the Badische .Anilin and Soda Fabrik at Ludvvigshafen, the 

 synthesis of ammonia from its elements at high pressure may 

 be safely counted among the means on which agriculture can 

 depend for the sujjply of nitrogen products. 



BRITISH WEST INDIAN TRADE WITH 

 VENEZUELA, 1908. 



From information received at His Majesty's Legation at 

 Caracas from the various British West Indian colonies relative 

 to the trade between them and Venezuela, the following figures 

 have been taken for the year 1908; — 



Im|)orts from Exports to 



Venezuela. Venezuela. 



£ £ 



Barbados 61 2,366 



British Guiana (1908-9) 420 71 



Windward Islands 378 315 



Trinidad (1907-8) 424,322* 52,279* 



The exports from Venezuela to Demerara consisted of 

 cattle, and to Trinidad and Grenada, of cacao, balata gum, 

 cattle and hides. {Diplomatic and Consular Reports, No. 

 4515 Annual Series.) 



The synthetical production of ammonia has, .so far, beer. * Exclusive of transhipment trade. 



