No. 6. DEPARTMENT OF AGRICULTURE. 621 



Carbolic acid (100 per cent), 2 quarts. 



Good fish oil, either whale or Menhaden, 2^ quarts. 



Caustic potash, pnre granulated 75 per cent., 1 pound. 

 Heat these in a covered kettle, in the open air, to 300 degrees 

 Fahrenheit. That takes a very few minutes to do this — possibly 

 fifteen minutes. Then we let it cool and add 8^ quarts ot Kerosene, 

 and 5^ gallons of water. That is the emulsifier. Instead of remov- 

 it from the fire, we can simply bank the fire to add the kerosene. It 

 is not advisable to add it while over the blazing fire. Then we make 

 the soluble oil; this is made as follows: 



Emulsifier, 8 parts. 



Crude oil, 4 parts (Warren sand oil will do). 



Resin oil, 4 parts. 



Water, 1 part. 

 This costs from 16 to 18 cents a gallon, and in applying it you 

 take one part to 16 gallons of water; so it makes the material cost 

 you about one cent per gallon as it goes on the trees. This cost is 

 figured in this way: 



Carbolic acid, 52 cents. 



Fish oil, 15 cents a gallon. 



Caustic soda, 15 cents a pound. 



Kerosene, 9 cents per gallon, by the barrel. 



Resin oil, 30 cents a gallon. 

 This does not take as long to prepare as the lime and sulphur, but 

 we must remember that it is not a fungicide, while the lime and sul- 

 phur is. There is no reason to suppose that this is injurious, as is 

 the case with the majority of oils, and it has the advantage, in com- 

 mon, with the lime and sulphur, of destroying the scale. 



I have letters from hundreds and hundreds of people who have 

 saved their trees by the use of lime and sulphur, and on the other 

 hand, I have letters from others who have destroyed their orchards 

 by the use of some of these commercial oils that are on the market. 

 Take the case of one material that is on the market, called the "Tar- 

 get Brand Scale Destroyer." At present, it appears to have a good 

 hold on the market, and yet I know of a case where a man had thirty- 

 five hundred trees and killed four hundred of them by its use, — 

 some of his very best trees, and- 1 can name instances of other peo- 

 ple who have lost their trees. 



Now, as long as we continue to use such commercial preparations, 

 and to encourage their manufacture, we cannot hope to get the 

 results in our orchards that we want. 



DEMONSTRATION ORCHARDS. 



BT PROr. H. A. SUBFACK. 



The chief new feature of the work of the Economic Zoologist for 

 the year 1908 is to be the establishment of a number of demonstra- 

 tion orchards in the State of Pennsylvania. The purpose of under- 

 taking this work is to show in a practical way just how to control 

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