FIRST USE OF PARIS GREEN. 39 



occasion to lecture before the congress on economic entomology, and to suggest, in 

 answer to inquiries from Gen. William H. Jackson, of Nashville, Tenu., and Dr. J. O. 

 Wharton, of Ferry, Miss., that the Paris green mixture which was doing such good 

 work in preserving our potato fields against the ravages of the Colorado potato-beetle 

 might prove equally efficient against the ravages of the insect which takes the place 

 of this potato enemy in the cotton fields of the .South. 



At the Indianapolis meeting' of the congress, according to Professor 

 Stelle, after the reading of Professor Riley's paper, Mr. Donovan rose 

 and made the statement that he had used the poison the previous year, 

 ] 872, at the recommendation of the Mobile Register. The whole question 

 indeed, as to whom the credit is due, is involved in doubt ; it is, however, 

 not a question of paramount importance. 



In early fall, 1S73, the following circular was issued by Commissioner 

 Watts, with a view of ascertaining the practical workings of Paris 

 green : 



PROTECTION AGAINST COTTON INSECTS. 



To Correspondents : 



The annual losses of cotton from ravages of cotton insects amount possibly to half 

 a million bales in years of insect prevalence, One-fourth of a million bales would be 

 deemed a light infliction, and yet, at $100 per bale, such a loss would be equivalent to 

 $25,000,000. The methods to be employed for lessening their ravages have been here- 

 tofore canvassed by the entomologist of this department. The remedy can only be 

 applied by the planters themselves, and their own experience can best render practi- 

 cable and efficient the means employed. 



Numerous correspondents have of late been experimenting with a mixture of Paris 

 green and flour or plaster, dusted on the plants when wet with dew a remedy which 

 lias proved very efficient against the Colorado potato-beetle and other insects. Some 

 report this remedy effectual against the cotton-caterpillar, while others declare it of 

 no value whatever ; ochers, still, hesitate to try it for fear of poisoning. It is of the 

 utmost importance that the facts in the experience of planters the present season 

 should be carefully reported, showing the quality and proportions of material used, 

 the method and frequency of its application, and the observed results, that a thorough 

 test may be made of its value or worthlessness. The answer of the following questions 

 is therefore requested : 



I. What is the result of your experience or observations as to the efficacy of Paris 

 green, or other arsenical compounds mixed with flour or plaster, for the destruction, of 

 the cotton-caterpillar f 



II. In what proportions, and in what mode, time, and frequency of application have 

 experiments been made ? 



III. Have any injurious effects of the poison been observed, either upon the plants 

 or the soil, or in human poisoning in its application, or in the destruction of beneficial 

 insects, as bees, &c ? 



IV. Have you used any other remedies, or means of extirpation, such as fires or 

 torches in the fields to destroy the perfect moths on their first appearance, and with 



What SUCrcs.S .' 



Yours, resppctfullv, 



FRED'K. WATTS, 



Commissioner. 



The report on the answers to this circular as published in the depart- 

 ment report for 1873 show the results of most experiments with Paris 

 green to be highly favorable to its use as a remedy, and it has since 

 been extensively used throughout the South. There are still many who- 



