ARSENICAL COMPOUNDS ^DRY APPLICATION. 141 



hand, be used as a diluent, but that it is a poor substitute for flour. Its 

 chief demerit is its greater weight, which renders the application both 

 inconvenient and wasteful. 



Before applying any poison in powder form it must be mixed»with 

 some of the diluents already mentioned. This mixing, generally done 

 by farmers in a most primitive way by simply stirring the poison into a 

 kettle or wooden box full of flour or other diluent, is a matter of no 

 small importance, as the success or failure of the application largely 

 depends on the way in which the mixing has been done. 



Mr. George Little, of Columbus, Tex., has constructed a very simple 

 and useful contrivance for mixing the ingredients. It consists of a bar- 

 rel which has a longitudinal wooden axle projecting somewhat at each 

 end. Five or six staves run through the barrel longitudinally, but do 

 not project at either end, and on one side is an aperture large enough to 

 admit the ingredients. When they are in, the aperture is closed and the 

 barrel is placed over a large open box, or fixed in any way so that it can 

 be revolved by means of a handle attached to the projecting axle. By 

 this simple and cheap contrivance much labor is saved and a thorough 

 mixing assured, while all possible danger which might be incurred by 

 hand-mixing is avoided. Large spikes driven through the sides so as 

 to project inwardly will add to the efilcacy of the device. 



In the matter of applying the powder, many planters prefer simply 

 to scatter it by hand, after the manner of seed-sowing, as being more 

 economical and rapid than any other method in use. It has, moreover, 

 the advantage that, if the plants are high enough, the poison can be ap- 

 plied to the under side of the leaves. Planters who use this method 

 assert, upon inquiry, that no evil consequences have ever followed their 

 handling of the mixture in this way, but it strikes us as being altogether 

 too unsafe to be recommended, and cannot compare on a large scale 

 with the devices described in the ensuing chapters. 



The principal expense in the dry application, as hithetto practised, 

 consists not so much in the cost of the poison as in that of the diluents, 

 and it occurred to us to try and reduce the amount of these diluents to 

 a minimum or to dispense with them altogether by applying the re- 

 quired* amount of poison unmixed. The experiments made in this di- 

 rection have not been satisfactory for want of suitable machinery, the 

 amount of poison used for each plant being always too large and not 

 evenly distributed. They prove, however, that with our improved blow- 

 ers much may be done in the direction of reducing the diluent. 



In the application from above it has been found useful to add a cer- 

 tain amount of finely-powdered substances of still greater adhesive 

 qualities than is possessed by any of the diluents, mentioned, in order 

 to prevent the poison from being washed away by the rain. Such sub- 

 stances are dextrine, gum arable, slippery-elm bark, or rosin. In very 

 rainy weather it is better to add a larger proportion of them than in dry 



