DRY APPLICATION OF LONDON PURPLE. 151 



overdoses of London purple. In other cases the failure was plainly 

 to be attributed to the imperfect implements used for the distribution 

 of the dry and wet poisons. In still other cases the cause of the fail- 

 ure could not be made out. The conclusions we arrived at during the 

 season of 1879, after a long series of trials made by ourself and Mr. 

 Schwarz, and assisted by the most experienced planters in the vicinity 

 of Columbus, Tex., and which were published in the first edition of 

 this work, have been proved correct by the experience of subsequent 

 years, and wherever pure and genuine London purple has been applied 

 according to the directions, it has always given satisfactory results. 



It should be remembered that the introduction of a new remedy, 

 especially if it is not without drawbacks, is always a difficult task, and 

 experience must be bought at the cost of disappointment and failure. 

 We need only recall to the reader the history of the introduction of the 

 Paris green, and how long it took before its efficacy was firmly estab- 

 lished, and before the farmers and planters had gained full confidence 

 that it was a perfect remedy for some of our worst insect enemies. 

 London purple has, in common with all arsenical poisons, the disadvan- 

 tage of danger, but it is one of the cheapest remedies of this class, being 

 a mere refuse which, from its poisonous nature, was a drug to the manu- 

 facturers, and had to be gotten rid of by being dumped long distances 

 out at sea. This substance can be put upon the market at the bare 

 cost of transportation. It can be sold in New York at the low rate of 

 6 cents per pound, and there is no reason why it should not be obtained 

 at any of the large shipping points in the South at figures ranging be- 

 tween 7 and 10 cents a pound. This means virtually that the cost of 

 destroying the worms by this powder is reduced to such a minimum as 

 to depend mainly on the labor and the other ingredients or diluents 

 employed j in other words, that, whije the planters, as heretofore, were 

 obliged to pay as much as $1 for the first cost of the active poison 

 needed for one acre, and never less than 15 cents, they may now obtain 

 it for from 3 to 5 cents. 



An advantage of minor importance is its red hue, as it colors the 

 ingredients so as to prevent their being mistaken for harmless material. 

 The finely pulverized condition of the purj^le seems to be of less ad- 

 vantage than we were formerly inclined to believe, as it increases the 

 caustic power of the poison upon the plants. Finally, its cheap price 

 removes the temptation of adulterating the poison, as every adultera- 

 tion would prove more expensive than the genuine article. 



Dry application. — Experiments on a large scale have been made with 

 the dry ai)plication at the rate of 2 pounds to 18 pounds of diluents, 

 also at the rates of 1, J, J, and J pound to 18 of the diluents. The last 

 proved only partially effectual, and in no case were the plants injured 

 or the leaves even burned. In all but the last case the worms were 

 killed, but as the mixture, at the rate of J pound, was applied with 

 greater care and regularity than is generally had on a large scale, and 



