3G2 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



Conchylis anibigneUa, Hubn. (cochylis of the vine). — Numerous 

 trials have been made. Zechini and Silva destroyed the vine-worm 

 by a 3 per cent emulsion. They obtained the same result with an 

 emulsion of 1 per cent of creoline and 1 per cent of nitrobenzene. Like 

 Dufour and Fleischer they found this treatment was very prejudicial 

 to the leaves and grapes. They therefore sought to discover other 

 mixtures, such as : — 



TABLE LXX.IX. — Showing Compositio?i of" Creoline " Mixtures ivhich gave Good 

 Results against Cochylis. 



These were quite satisfactory. Martini reduced the cochylis 65-68 per 

 cent by two treatments, one in the end of April, the second in the 

 beginning of May, with an emulsion containing ] -5 per cent of Nava 

 creoline, 1 per cent of lime, and 1 per cent of blue vitriol. 



137. Creosote [wood tar], — Creosote is a mixture of different 

 phenols. Chemists who have studied the subject are divided in their 

 opinions as to its constitution. According to Marasse creosote con- 

 tains phenol, cresol, phlorol, gai'acol, and creosol. 



Preparation. — Creosote is extracted from wood tar, chiefly beech 

 tar, by distillation. The oily layer of the condensed liquid contains 

 creosote. This oily layer is again distilled, only the portions denser 

 than water are collected. When the product so obtained is treated 

 with a solution of caustic potash the hydrocarbides remain undissolved, 

 whilst creosote dissolves. Creosote is precipitated from its solutions 

 by sulphuric acid. Soot contains a certain amount of creosote. 



Properties. — Creosote is a refractive, colourless, oily liquid, with a 

 smell of smoke and a burning taste. It does not d'ssolve in water, 

 but is very soluble in alcohol and in alkaline lyes. Creosote dissolves 

 resins and sulphur, coagulates the albumen of blood and of white of 

 egg. It is a strong caustic and one of the best organic antiseptic^, but 

 it has a prisonous action, like that of carbolic acid. It is used in the 

 state of vapour as a meat preserver, and in solution for the preservation 

 of wood, which it preserves both from insects and saprophytic fungi. 

 Its action on plants and insects is very analogous to that of carbolic 

 acid. 



Use. — Meridius lacrymus, Schum. (rot of building timber, dry rot). 

 — " Carbolineum," consisting almost entirely of creosote, is recom- 

 mended against this fungus. 



Haltiea (altises). — The bad smell of soot causes it to be used to 

 drive away altises. Thiele records several failures. Mohr recom- 



