522 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The shrub is about 1 m. in height and easy to grow, but the seeds are 

 capricious in germinating. — F. A. W. 



Black Currant. By J. Vercier (Le Jard., vol. xxiii. No. 531, p. 107, 



also pp. 124 and 187 ; with figs.). — Either alongside of the vine, as is 

 suggested in this article, or as a separate industry, much may be made 

 of Bibes nigrum, the black currant. At present seven million kilo- 

 grammes of this fruit are produced in France, and after providing for 

 the manufacture of the liqueur Cassis at Dijon and elsewhere are sent 

 over to this country for jams and preserves, on which the author compli- 

 ments the English makers. A list of varieties under cultivation is given, 

 but all are pronounced inferior to the Naples Royal, which is almost ex- 

 clusively cultivated in the Cote d'Or. Minute directions for culture are 

 given, but are too lengthy to reproduce here. By the third year the yield 

 of fruit should repay initial cost, and goes on increasing to the seventh or 

 eighth year, when a maximum is attained and kept up. One bush may pro- 

 duce two to three kilos, if standing clear ; one field may yield 6,000 kilos, 

 and women can pick the fruit. Even the leaves were formerly valued for 

 their astringent properties, and French doctors are again recommending 

 them, as an infusion, for rheumatism. M. Vercier appeals to his 

 compatriots to learn to make the ' pulpe de cassis,' which the English 

 excel in.— F. A. W. 



Bog-Soil, Poisonous Matters in (Bot. Gaz. vol. xlvii., No. 5, 



pp. 389-405, May 1909 ; with 2 figs.).— Mr. Alfred Dachnowsky 

 describes certain very ingenious experiments which go to prove that the 

 infertility of many bogs or "muck and swamp lands " is due to the fact 

 that bog toxins or poisons exist in bog water and that therefore such 

 lands even after being drained and supplied with fertilizers do not give 

 satisfaction. Moreover xerophily (dry climate characters) of bog plants 

 is not entirely caused by the acidity of peaty soil, by the lack of oxygen, 

 or by low temperature, but in part results from these injurious substances. 



When wheat plants were grown in untreated bog water, he found 

 upon the roots numerous coloured bodies, which were apparently formed 

 by the oxidizing substances given off by the roots. But as the root tips 

 were decayed, it was clear that the roots were unable to overcome the bog 

 toxins. 



If bog water is treated with some absorbing substance, the result is 

 invariably beniefical especially if the latter material is fine-grained. 

 Humus and carborundum are about four times as absorptive as quartz, 

 so that humus has great capacity for retaining the poisonous materials. 



G. F. S.-F. 



Bordeaux Mixture. By the Duke of Bedford, K.G., and Spencer 

 U. Pickering. F.R.S. (Wobum, Eighth Beport, 1908, pp. 5-14).— When 

 made in the ordinary way by adding milk of lime to copper sulphate a 

 double basic sulphate of copper and calcium is formed, and it does not 

 possess fungicidal properties until the action of the carbonic acid of the 

 air has formed carbonates and sulphates of the metals, and the re- 

 formation of the sulphate of copper does not begin until all the basic calcium 

 sulphate has been converted into carbonate, thus explaining the lapse of 



