ETHYL ALCOHOL. 313 



water, and maintain in solution therein the insecticides insoluble in 

 water. 



115. Methyl Alcohol, CHpH.— Preparation.— Methyl alcohol 

 •or wood spirit is a product of the dry distillation of wood. 



Properties. — Methyl alcohol is a colourless mobile liquid which 

 boils at 66'0° C. It dissolves most substances soluble in ordinary 

 alcohol, such as essential oils and resins. Oxidizing agents convert 

 it first into formol and then into formic acid. [Highly inflammable.] 



Use. — As a solvent in place of ordinary alcohol which it can re- 

 place in all insecticides with an ethylic alcohol basis. 



Phylloxera. — Two mixtures have been patented in Germany for 

 the destruction of this louse. The D.R.P. 50772 claims a solution of 

 turps and quassia in methyl alcohol, and D.R.P. 47775 claims a solution 

 •of animal oil, colocynth, etc., in methyl alcohol. 



Galeruca luteoLa (galeruca of the elm) ; Erymia nitida (diptera 

 living on the elm). — It is recommended to destroy these by a mixture 

 of water 100 gallons, tobacco juice 1 gallon, soft soap 10 lb., methyl 

 alcohol 1 gallon, carbonate of soda 2 lb. 



116. Ethyl Alcohol, CoH-OH.— Preparation. — By the action of 

 yeast on saccharine solutions certain sugars are under such conditions 

 •converted into alcohol and carbonic acid. x\ll that has to be done is 

 to distil these liquids to obtain alcohol. Purification is effected by 

 redistillation of the first distillate over lime. 



Properties. — Alcohol is a colourless limpid liquid with an intoxi- 

 cating odour ; it dissolves in water in all proportions. Alcohol is a 

 precious solvent not only of inorganic compounds like caustic alkalies, 

 mineral acids, chlorides, and nitrates, but also of numerous organic 

 compounds, such as essential oils, resins, camphors ; it also dissolves 

 fatty bodies, but with greater difficulty. Alcohol boils at 78-4" C. 



Action of Alcohol on Plants. — Sandsten examined the action 

 of alcohol on the growth of plants in a nutritive fluid. Alcohol in 

 solution of 1 in 10,000 to 1 in 20,000 does not affect the growth of 

 young plants of phaseolus, vicia, and maize. A 2 per cent solution is 

 injurious, it excites the movements of the protoplasm and causes 

 death. The vapours of alcohol may become prejudicial to the health 

 of the plants if the atmosphere contains more than 1 in 10,000 ; gi'eater 

 amounts stop growth and cause death. Hiltner found that whilst 

 ordinary alcohol of 95 per cent strength injures seed, absolute alcohol 

 ■on dry seeds has no injurious effect. Alcohol would appear, therefore, 

 to act on seeds like ether and chloroform. 



Use against Insects. — Disinfection of Flower Seed. — Hiltner 

 recommends to wash with absolute alcohol. The seeds should be dry 

 and thus without protoplasmic activity. 



Plant Lice. — Alcohol enters into the composition of many in- 

 secticides recommended against plant lice, but it is not so active as 

 amylic alcohol which replaces it with advantage in all these mixtures. 



Schizonenra Lanigera, Hausm. (woolly aphis). — Liniere recom- 

 mends a mixture of alcohol 30 oz., water 20 oz., potash 1 oz., applied 

 by the brush on the colonies. In Germany this aphis is easily got rid 

 •of by drenching the colonies and the cankers which they produce, and 



