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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY, 



on under great pressure. If the plants have had a dose of the dreaded 

 ' black spot ' a still harder fight has to be made. The leaves are picked and 

 carefully burnt ; care is taken that the foliage is not wet on dull days, and 

 every effort made to keep the plants in as healthy condition as possible. 

 As a preventive, and to kill whatever spores there may be around, on clear 

 mornings a spraying is given with some one of the copper solutions, as the 

 modified ' eau celeste ' or the ammoniacal solution of copper carbonate. 

 Many formula? are given and all advise the use of the commercial copper 

 carbonate, but we have found it better in every way to make our own salt, 

 precipitating from aqueous solutions of sodium carbonate and copper 

 sulphate, carefully washing out the sodium sulphate and dissolving the 

 copper carbonate in ammonium hydroxid, 26° Baume. This stock 

 solution, securely corked, will keep indefinitely. Greatly diluted it is 

 sprayed on the plants with a knapsack pump, or, best of all, one of those 

 pumps now on the market in which the spray is driven out by compressed 

 air. For mildew the standard remedy is flowers of sulphur, applied either 

 on the plants themselves by means of a powder-gun , or mixed with water 

 it is painted on the heating pipes for vaporisation. The sulphur is some- 

 times vaporised over an oil stove, a most unsatisfactory method and 

 dangerous, as the sulphur is apt to catch fire and cause great damage. A 

 troublesome kind of invader is the green fly — the aphis — which the ant so 

 carefully treasures. It yields only to nicotine. Heretofore, stems fresh 

 from the stripping room of the tobacco factory were used. They were 

 burnt in a metal " smoker," but not allowed to blaze, and drawn through 

 those houses which were planted with varieties sufficiently sturdy to with- 

 stand the heat and dense smoke of the burning stems. In those houses 

 containing the more delicate varieties, the stems were laid in every way 

 imaginable (trying to make the best of a poor arrangement) on the benches 

 and under them, in wire-net baskets for ease in renewing them. At the 

 present time it is almost impossible to get good stems, as they are leached 

 to extract the nicotine used in the manufacture of the preparations which 

 are gradually supplanting them. These do away with much of the dis- 

 comfort and disorder attendant upon the use of stems, and of the danger 

 from fire from the superheated " smoker." The various liquid extracts are 

 not satisfactory ; the strength of the solution becomes so concentrated on 

 standing that it gives an unduly strong fumigation, resulting in disaster in 

 the hands of heedless employes. The soap-forms are made for spraying, 

 with the disadvantage that it is not always possible to wet the plants 

 when the aphis is worst. As satisfactory a preparation as is made at 

 present is that sent out by the Scaboura Dip Company of St. Louis under 

 the name " Nikoteen Aphis Punk." A stick of punk is a strip of paper 

 dipped into the nicotine solution of proper strength, dried, rolled, and 

 packed in boxes containing one dozen sticks. The sticks are lighted and, 

 smouldering in the house, give off a pungent, penetrating odour which 

 seems to be the sure death to the aphis for which all stony-hearted Rose- 

 growers are seeking. Smoke from the aphis punk does not injure in the 

 least the most delicate Roses. An illusive microscopic pest is the eel- 

 worm, which enters the plant from the soil. The only remedy is burning 

 the infected plants and removing the adjacent soil. For the thrip, which 

 deforms the bud and is so hard to reach, pyrethrum powder is burnt. 



