138 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



Finally, too much stress cannot be laid on the importance of having 

 the materials ready, prepared in advance, or on their use as soon as the 

 eggs or young worms are noticed. It is too often the habit to wait until 

 the plants begin to be '^ ragged" before attempting to poison. The 

 operation is always more costly and unsatisfactory at this period, and 

 there is danger that, with the most strenuous efforts, irreparable dam- 

 age will be done before all the cotton is gone over. It often happens, 

 also, since the same influences cause the multiplication of the worms 

 over pretty large areas, that a sudden and general demand for the poi- 

 sons by those who have not previously laid in a stock increases the price 

 or exhausts the market, so that many are left without hope of saving 

 their crop. 



ARSENICAL COMPOUNDS. 



Arsenical compounds have the acknowledged disadvantage of being 

 dangerous to man and beast. Some writers, taking a most narrow and 

 theoretical view of the subject, bitterly object to their use on the score 

 of their dangerous character, exaggerating in their enthusiasm the in- 

 jury that has resulted from their use. Kot only hundreds of tons, but 

 thousands of tons of these mineral poisons have been employed during 

 the past decade by farmers throughout the country, whether to protect 

 the potato crop, or the cotton crop, or other products of the soil from 

 the ruinous attacks of insects. The general experience during this long 

 period and over the whole country is so emphatically in favor of their 

 use and their perfect safety and harmlessness, with ordinary precau- 

 tions, as to render almost laughable the objections of the few persons 

 referred to. ]^o advancement, no improvement, no general benefit to 

 the human race is ever accomplished without some attendant danger, 

 and those who inveigh against such improvements as increasing the 

 risks to life stand on the same footing as the opponents to arsenical 

 poisons as insecticides. It is a noteworthy fact that, since we have been 

 pursuing this cotton insect investigation, not a single fatal case of 

 human poisoning by the use of these minerals against the worm has 

 come to our notice from the South, notwithstanding they are often used 

 in that section of the country with great recklessness. Nevertheless, 

 it is no uncommon thing to hear of partial poisoning among negroes, 

 resulting from that indifference which comes from constant use, and the 

 importance of care and caution cannot be too strongly urged, especially 

 near towns or in thickly settled neighborhoods.^^ 



None of the correspondents of the Commission report serious injury 

 to man by arsenical poison in its application for the Cotton Worm, 

 and only one of them reports directly a case of poisoning a horse ; all 

 others report such cases from hearsay. 



It has been our principal ambition to discoyer some substitute for 

 these poisons that shall be equally effectual, harmless to man, and 

 cheaper. The experiments that have been carried on by the Commis- 

 sion with this object have been sufficiently encouraging, as the sequence 



