EXPERIMENTS WITH WET POISONS. 



223 



In the following table the quantity of poison per barrel of water is 

 given, but in some sections several barrels were used : 



*In all of my experiments where paste was used it was made by boiling wheat-flour in water, so as 

 to be a trifle thicker than the starch commonly used for stiffening linen articles. Some farmers, to 

 avoid the labor of boiling the paste, allow flour to ferment in water, obtaining a very good article in this 

 way. In either case it should be strained through muslin. Mr. Patrick Calahan, of Selma, merely stirs 

 two pounds of common starch in a bucketful of cold water, which is then added to 40 gallons of water 

 containing the poison. 



When applying the poisons to sections 10 to 14, inclusive, we used 

 two mules to draw the distributing wagon, in which were the driver 

 and two hands with pumps. Another hand, with a two-mule wagon, 

 was engaged in drawing water from a pond to the ends of the cotton 

 rows, where it was transferred to the other wagon. Owing to the low 

 specific gravity of London purple, the bulk of a pound of it is far greater 

 than that of an equal bulk of arsenic or Paris green, and the hands com- 

 plained that it pumped out harder than either of the other poisons 

 named. Certain it is, that, other conditions being about the same, a 

 barrel went over three acres in section 11, while in 12, 13, and 14 it went 

 over only two. On section 10 the pumps were worked less rapidly, so that 

 a barrel of water went over three acres. Twenty-four hours after each 

 section was poisoned I examined it to see what eifect the poison had 

 produced on the worms and cotton, and leaves plucked here and there 

 were examined with a lens to discover how thoroughly the finely divided 

 poison was applied. There was a considerable number of worms dead 

 on section 10, and most of the others died before the first rainfall. The 

 Paris green could be seen in very fine particles in the minute hollows 

 everywhere on the surface of the leaf. The cotton plant was not in the 

 least injured. On section 11 the percentage of dead worms after twenty- 

 four hours was considerably less than on 10, but before the rain fell the 

 greater part of the others were dead. The poison appeared as a fine 

 purple bloom on the surface of the leaf, and iu a good many places the 

 leaves were scorched seriously. The arsenic used on section 12 did not 

 scorch the cotton, nor did it kill many worms at first, but later it 

 destroyed a good number. By far the best results were obtained on 

 section 13, where the worms were quickly and thoroughly killed, and 

 only at long intervals could a scorched leaf be found. Though the Texas 

 worm-destroyer, used on section 14, was applied according to directions, 

 it being stated that more than one measure, about 4 ounces to the 



