November 25, 1891.] 



Garden and Forest. 



557 



you the striking description which Professor Thiselton Dyer 

 has sent me of this deposit He says, ' It was like a brown 

 paint, it would not wash off with water, and could only be 

 scraped off with a knife. It thickly coated all the leaves 

 of the evergreens, and upon what have not yet been shed it 

 still remains.' . . With regard to plants under glass the effect 

 offogisoftvvokinds : (1) That caused by diminished light. 

 This checks transpiration. The plants are therefore in the 

 condition of being overwatered. A well-known conse- 

 quence of this is to make them shed their leaves whole- 

 sale. Many valuable plants which ought to be well fur- 

 nished with foliage become perfectly bare, and it is 

 impossible ever again to recover them into sightly speci- 

 mens. (2) The toxic influence of the fog. This is most 

 striking. I attribute it in the main to sulphurous acid, 

 though I cannot help suspecting that some hydrocarbon 

 may also have something to do with it. The toxic effect 

 varies from one plant to another ; some are scarcely in- 

 jured, others are practically killed. I hope you will be able 



fund has been started. Should the scheme be practicable, 

 and there does not appear to be any reason why it should 

 not, this exhibition ought to prove an important event in 

 horticulture, and even in agriculture, for there are signs 

 now of the cultivation of fruit being taken in hand by 

 farmers. Sir James Whitehead has almost promised on 

 behalf of the corporation the use, free of charge, of a site 

 on the Thames embankment for the exhibition, which will' 

 be extended over a period of about ten days. It is antici- 

 pated that the foreign section of this exhibition will be a 

 prominent feature, and among foreign growers of fruits for 

 the English market the United States occupies a very prom- 

 inent place. No such exhibition has been held in England 

 since 1866, when a great show of fruit was held in London 

 and was so successful that after paying all expenses there 

 was sufficient profit to purchase the Lindley Library for 

 the Royal Horticultural Society and to present £1,000 to 

 the Gardeners' Benevolent Institution. 



I forward you a copy of a leaflet which is being distributed 



Fig. 87. — A Pond in Southern Illinois, covered with the Water Chinquapin (Nt 



. — See page 556. 



to arouse some interest in this horrible plague. If the vis- 

 itation of last year is annually repeated it must in time 

 make all refined horticulture impossible in the vicinity of 

 London." That the number of fogs experienced in London 

 is annually increasing is shown by the statement that while 

 between 1870 and 1875 the number recorded for the three 

 months December, January and February was ninety- 

 three, the number for a similar period ending last year had 

 increased to 156. Dr. Russell does not write hopefully of 

 the possibility of getting rid of this winter plague. He 

 says as long as coal is burnt we shall have dense fogs, and 

 it does not appear probable that a substitute will be found 

 for coal. 



Fruit. — Arrangements are being made to hold a great 

 National and International Exhibition of Fruit in London 

 in October, 1892. It is expected that all the English socie- 

 ties interested in the cultivation of fruit will co-operate to 

 insure the success of this exhibition. A committee has 

 been appointed to formulate a scheme, and a guarantee 



all over England by the Royal Horticultural Society. It is, 

 as you will see, intended chiefly for cottagers and small 

 farmers, and is meant to afford them reliable information on 

 the best kinds of fruit for general cultivation. The list, with 

 cultural notes, has been drawn up by forty leading experts 

 in fruit-culture in England. It gives the names of the 

 twelve best apples for cooking, the eight best apples for 

 dessert, the twelve best pears, twelve best plums, and a 

 selection of cherries, damsons, raspberries, currants, 

 gooseberries and strawberries. The habits, time of fruit- 

 ing and keeping qualities of each are given, with a few 

 important directions on planting, pruning, manuring, etc. 

 The aim has been to make the list applicable as far as pos- 

 sible to the whole of England, and to include only varie- 

 ties possessing the four most necessary characteristics of 

 quality, fertility, good growth and hardiness. The leaflet 

 consists of eight pages, and it is to be had at the rate of 

 2s. 6d. per 100 copies. 

 Kew. W. Watson. 



