I02 Amials of Hortiadtiire . 



of the mixture were poured into each hole and found to pene- 

 trate from 12 to i6 inches or from i8 to 22 inches from the 

 original surface of the ground. Most of the insects, as also 

 the eggs, were destroyed to a depth of 16 inches. In the 

 later experiments the holes were made only about 2 feet in 

 diameter, and nearly, if not quite, the same results were ob- 

 tained with half the amount, or 5 gallons of the mixture. 

 The plan, which I had previously adopted for the applica- 

 tion of insecticides to underground insects, of washing the 

 mixture in with pure water was tried with good success. Soon 

 after the first application 5 gallons of water were added, and 

 5 gallons more the following day. This would indicate that 

 in the spring, when rains are frequent (occurring almost every 

 day) in the Sonoma Valley, only a small amount of the mix- 

 ture need be applied, and the rains will do the rest, as exam- 

 ination has shown that up to a certain point each application 

 of water intensifies and extends the action of the original in- 

 secticide. The best soap was made with bicarbonate of soda, 

 but the results of that made with caustic soda are so little in- 

 ferior, while the price is so much less, that the caustic soda 

 and resin soap mixture is the one which I would recommend. 

 The formula which was found preferable is as follows : 



Caustic soda (77 per cent.) 5 pounds 



Resin 40 



Water to make 50 gallons. 



**The soda should be dissolved, over a fire, in 4 gallons of 

 water, then the resin should be added and dissolved. After 

 this the required water can be added slowly, while boiling, to 

 make the 50 gallons of the compound. To this, water may 

 be added at the rate of 9 gallons for i, making 500 gallons of 

 the dilute compound, sufficient for one hundred large vines, 

 at a cost of only 84 cents, or less than a cent a vine. 



''Considering the effective way in which the ravaged vine- 

 yards of France have been, and are being, redeemed by the 

 use of resistant American stocks, and considering the efficacy 

 of some of the direct remedies discovered, it is passing 

 strange that no disposition has ever been made of the pre- 

 mium of 300,000 francs offered in the early history of the 

 trouble by the French government. It cannot be awarded 

 to an}^ one person, but should be distributed among those 



