162 EXPEKIMENT STATION RECORD. 



In general it is believer! that nursery stock is more injured by the treatment 

 before and after fumigation than by the process of fumigation. In order to 

 obtain successful results it is necessary that the fumigating house be gas tight 

 and that the chemicals he of high grade. Fumigation of orchard trees in Ohio is 

 considered impracticable. 



Spraying fruit trees, A. Dickens and K. E. Eastman {Industrialist, 32 

 (1901!), Xo. 2S, pp. 'i-r>-'i'i'i. fif/s. -'/).— During recent years it is said that the 

 quality of fruit produced in Kansas has somewhat deteriorated on account of 

 lack of attention to the necessity of spraying. The general imi)ortance of spray- 

 ing is briefly referred to and notes are given on methods of controlling codling 

 moth and other insects, together with an account of some of the most effective 

 insecticides, such as arsenate of lead and a combination of Bordeaux mixture 

 and Paris green. 



Petroleum emulsions, C. L. Penny {Delairurc St a. Bill. 7.5, pp. 39). — On 

 account of the importance of soluble oils in spraying for various scale insects, 

 the author made a study of various methods by which such combinations can be 

 brought about. 



It appears that a potash soap can be dissolved in kerosene more readily than 

 a soda soap. Soaps are most efficient as emulsifiers when they are made from 

 ueatsfoot or sweet oil, while those made from cotton-seed oil. lard or castor oil 

 are poorly adapted to the purpose. Commercial oleic acid and fish oil seem to be 

 particularly excellent emulsifiers. Various combijiations may be used in produc- 

 ing soluble oils. It is not necessary to use soap alone, but carbolic acid, ammonia, 

 alcohol, or even water may assist. If soap with or without other materials is 

 capable of emulsifying 25 times its weight of kerosene oil the ratio is said to be a 

 high one. The author found it possible to prepare an emulsifier which would 

 produce a satisfactory emulsion when mixed with 40 to 100 times its weight of 

 kerosene. 



It is found that if emulsions are made without any free oil they may then be 

 diluted with water indefinitely without danger of separation into component 

 parts. In general it is desiraljle to obtain a mixture with a high ratio or one in 

 which the amount of oil is very large as compared with the soap. It appears 

 that if a little water is added to the soap before mixing with the full amount of 

 kerosene the emulsion is made much more easily. 



After pi-eparing soluble oils by means of an emulsifier and kerosene or petro- 

 leum it may seem desirable in some cases to add some other insecticide to the 

 mixture. Most of these substances, however, are incompatible with soluble oils 

 and cause them to decompose. Paris green is about the only exception. 



A number of detailed formulas are given for the preparation of the petroleum 

 emulsions. The various fornudas are given for the purpose of showing how 

 emulsions can be made but without recommendations of their efficiency in 

 destroying insects since they have not been thoroughly tested by the station. 



Chemistry of insecticides and fungicides, F. T. Shutt {Canada Expt. Farms 

 Rpts. 1905, pp. lJi9-154). — The soda-Bordeaux or Burgundy mixture was pre- 

 pared according to 2 formulas calling for 4 to lbs. of copper sulphate and 5 to 

 7i lbs. of carbonate of soda per 40 gal. of water. 



This mixture has been used chiefly for potatoes. It was tested on orchard 

 trees with the result that it proved harndess to the foliage except when Paris 

 green was used in connection with it. Brief mention is also made of the use of 

 limold in the preparation of kerosene emulsion and of flour also used for this 

 purpose. It is found possible to make a valuable emulsion with kerosene by 

 adding flour at the rate of 8 oz. to 1 qt. and water added at the rate of 2 gal. 

 for every quart of kerosene. After thorough churning the mixtui'e is then ready 

 for use. The flour emulsion spreads readily and does not clog the nozzle. 



