﻿10 SEVENTH ANNUAL REPORT 



prehension, and certainly support the opinion previously expressed on 

 the subject in these reports :* 



Past Experience. — In the early history of the use of this mineral 

 as an insecticide, most persons, myself included, were loth, on theo- 

 retical grounds, to recommend its general use ; and I have ever insisted 

 that the many other mechanical and preventive measures, which, it 

 persistently employed, are sufficient to defeat the foe, should be 

 resorted to in preference. But the mor'e diluted form and improved 

 methods now-a-days employed in using the poison, render it a much 

 safer remedy than it was a few years back; and no one should fail to 

 take into account that during the past six years millions of bushels of 

 potatoes have been raised, the leaves of which have been most thor- 

 oughly sprinkled with the Paris Green mixture, without any injurious- 

 effect to the tuber, or to persons using potatoes raised in this manner. 

 Indeed, scarcely any potatoes have been raised in the Middle States 

 during these years, without its use ; yet I have to learn of the first 

 authentic case of poisoning or injury whatever, except through care- 

 lessness and exposure to its direct influence. So far as experience 



* We hear many fears expressed that this poison may be -washed into tlie soil,. absorbed by the- 

 rootlets, and thus poison the tubers; but persons wh.) entertain such fears forget that they themselves 

 often apply to the ground, as noiu-ishment for tlie vines, either animal, vegetable or mineral substance* 

 that are nauseous, or even poisonous to us. Animal and vegetable substances, of whatsoever nature,, 

 must be essentially changed in character and rendered harmless before they can be converted into 

 healthy tubers, and a mineral poison could only do harm by being taken with the potatoes to the table. 

 That any substance, sprinkled either on the vines or on the ground, would ever accompany to the table 

 a vegetable which develops underground, and which is always well cooked before use, is rendered 

 highly improbable. There can be no danger in the use of sound tubers. But the wise and well-in- 

 formed cultivator will seldom need to have recourse to Pans Green, as he will find it more protitable to 

 use the different preventive measures that have, from time to time, been recommended in these 

 columns. 



The poison may do harm, however, by being carelessly used, and it is most safely applied when 

 attached to the end of a stick several feet long, and should not be used where children are likely 

 to play.— [3d Rep. , pp. 99-103. 



Some persons have even imagined that potatoes grown on land where it has been used are often 

 watery, rank and of bad flavor, .and according to the Monthly Report from the Department of Agri- 

 culture for August and September last, peas planted in soil mixed with the green rotted immediately 

 and would not germinate, while those in unadulterated soil grew finely and flourished, but died immedi- 

 ately when transplanted into the soil mixed with the Green. How far these statements are to be relied 

 on, each one must judge for himself, but it is certainly advis.able to avoid tis much as possible the use 

 of the poison, by carrying out the other methods, both preventive and remedial, advocated in previous 

 Reports; for wholesale remedies always have the disadvantage of destroying some friends with the 

 foes, and in this case tlie true parasites and those cannibals which by mastication partake bodily of their 

 green-covered prey, certainly fall in the general slaughter. But this remedy has now . been so 

 extensively used with good results and without any apparent harm to the tubers, that full and 

 thorough proof against it will be necessary to cause its abandonment. Properly mixed I have 

 used it without the slightest trace of evd elect on the leaves or tubers, and I know hundreds of other .s 

 who have done likewise; so that with )n-esent experience I should not hesitate to recommend its 

 judicious use. What is wanted on this subject, is a long series of thoroughly accurate and reliable ex- 

 periments. Let our Agricultural Colleges make them! Meanwhile Paris Green Avill be extensively 

 used, especially while the vines are young and most need protection; for after the expense of prepa- 

 ring the land and planting has been incurred, it will not do to get discouraged and abandon the field t'> 

 the enemy, when such an cflicient remedy is at hand. — [4th Rep., pp. 11-12. 



