THE USE OF PARIS GREEN AGAINST THE WORMS. 143 



impiiired by the rains, but because dry poisons can, if necessary, be ap- 

 plied without the aid of heavy machines, which cannot be drawn through 

 the fields in very wet weather. Dry arsenical poisons, especially when 

 mixed with diluents, are much less liable to injure the plants than when 

 applied in liquid suspension. 



PARIS GREEN. 



The nature and effects of this poison are now too well and generally 

 known among planters to need consideration. Planters have too often 

 found in its use a path leading from threatened ruin and bankruptcy to 

 be much influenced by theoretical arguments against it. A study of 

 its effects, based upon experience and experiment, whether u^jon the 

 plant or upon the soil, shows that no harm results from its judicious use.* 

 Our expectations in first suggesting its use as a Cotton Worm destroyer 

 at the Saint Louis meeting of the National Agricultural Congress, in 

 1872, and more confidently recommending it before the same body at 

 Indianapolis, in 1873, have been fully realized by the experience of the 

 past seven years. Complaints of its inefficacy are readily traceable 

 either to faulty ai)plication or to the use of an adulterated article. Its 

 principal disadvantages are its great cost, often increased by the ex- 

 orbitant profits demanded by merchants, and the consequent temptation 

 to adulterate or imitate the genuine article.^'^ Its advantage over the 

 other arsenical poisons, besides its undoubted efficacy, is that it is least 

 liable to scald the leaves and cause the young bolls to shed. 



If used in liquid suspension the amount of the green to be distributed 

 over one acre should not exceed one pound or be not less than half a 

 pound. The former amount is that more generally used, but, taking 

 into account the wastage and loss through rain or dew, the actual work- 

 ing quantity per acre is not much above one-half pound. The generally 

 accepted practice has been to take 1 pound of the green to each 40 gal- 

 lons of water, which amount of water was sufficient to go over one acre 

 when applied from above in a moderately fine spray or rain. 



The great advantage of the improved methods of application given in 

 this report is that they extend a given amount of liquid poison over 

 more than three times the area without loss of efficacy, and thereby re- 

 duce the cost to less than one-third of what it hitherto has been. 



If the green were as cheap as the other arsenical poisons, this saving 

 would be of little consequence j but, as the matter stands, it is of the 

 greatest importance, as will be seen from the following computation : 

 The price of Paris green in the South averages 40 cents per pound, being 

 rarely lower, and in times of general demand reaching as high as 75 

 cents or $1 per pound. We arrive at the cost of the wet application per 

 acre by adding to the cost of the poison and admixture that of the ma- 



* A discussion of this subject "will be found in a work by the writer entitled "Potato Pests," pp. 

 69-75. 



