Red Spider and WJiite and Broum Scale. 255 



In Krlinitz's EncyclopcEcUa, vol. 43., the article Charcoal is very comprehen- 

 sive with respect to its preparation and technical application ; but, with regard 

 to agriculture and gardening, it is only mentioned (p. 225.) that " charcoal 

 ashes serve to improve soils, and earth becomes very light by it." M. Lucas 

 says he has looked for it in Loudon's Encyclojitedia of Gardening, and found 

 no further information there than in Kriinitz. 



From this I think I may conclude that all that has hitherto been known 

 for the improvement of the soil by charcoal dust was only founded on casual 

 observations, and that experiments made with a view to science on this very 

 commonplace article, in the manner in which M. Lucas has pursued them 

 with so much success, have not been hitherto made. 



Mtmich, Feb. 29. 1840. 



Art. hi. On the Destruction of the Red Spider in Plant Structures. 

 By Robert Errington. 



A FEW facts are, I conceive, in the present state of horticulture, worth a 

 volume of speculations ; I therefore beg to forward you some statements of 

 what has taken place here, which, although of an isolated character, will, I 

 hope, be of some use. It is well known that the red spider is one of the 

 greatest pests of the gardener ; it is also well known that sulphur is destruc- 

 tive of that insect ; yet, in spite of all this, it is more frequently found in 

 gardens than it ought to be, considering that an antidote is at hand which is 

 both economical in cost and use, and certain in its effects. 



Few are disposed to use sulphur to the extent at which it may be used 

 with impunity, through fear of its pernicious effects on vegetation if pushed to 

 an extreme ; which fear, however well founded in fact, is carried to an un- 

 necessary extreme, as I am about to show. I have been in the habit of using 

 sulphur for this purpose for some years, and, although 1 have houses in which 

 most things are grown or forced which are peculiarly liable to that pest, yet 

 it seldom (I might almost say never) makes its appearance. 



As houses vary so much in their internal area, and as much depends on 

 apportioning the quantity of sulphur to that area, I will assume a case which 

 will be, I hope, a sufficient guide. For a house 30 ft. long, 16 ft. wide, 10 ft. 

 liigh at back, and 6 ft. high at front, I have been in the habit of using at least 

 4 oz. It is heated by hot water, and the pipes are of 6-inch bore. One man 

 with a watering-pot and syringe goes before the person who applies the sulphur, 

 and who is provided with a dusting-brush and the sulphur in a bowl. The 

 one syringes the pipes and the other applies the sulphur, until the pipes are 

 fairly painted from one end to the other, except the part at which the fire 

 enters for a few feet.. A dull day is chosen for the purpose, and at the time 

 of application I keep a rather brisk fire. If the house becomes insufferable 

 to my own lungs I allow a little of the surplus fames to escape at the back by 

 ventilation, especially should the sun peep out suddenly; however, this is 

 seldom necessary if the day be well selected. 



By these means, repeated about three or four times in a year, I am, as I 

 stated before, kept entirely free of this destructive pest. 



Oulton Park Gardens, April 'i:. 1841. 



Art. IV. On destroying the White and Brown Scale by the Applica- 

 tion of hot Water. By Henry C. Ogle. 



The difficulty of destroying the white and brown scale, on plants of any de- 

 scription, is well known to cultivators. Tiiey may be partially destroyed on 

 those plants having large leaves, by rubbing off and other means ; but this 

 would be an endless, and I may say a fruitless, task with plants having small 

 18H. — V. SdSer. s 



