72 



THE PRACTICAL ENTOMOLOGIST. 



the sailors." Wc laugh at such reasoning; for here 

 again we see that the After is coufountled with the 

 Because. But many an American farmer often 

 argues just as illogically. A certain insect is afflict- 

 ing one of his crops. Forthwith he scatters lime, 

 or ashes, or road-dust over it. The insect in tlie 

 course of a week or so disappears, probably because 

 the natural time had arrived for it to go under 

 ground to pass into the pupa state. . And then, hey 

 presto! we have lime, or ashes, or road-dust recom- 

 mended in print as an infallible remedy against the 

 attacks of this particular insect. 



Another most fertile source of error is the found- 

 ing general rules upon a very insufficient number 

 of experiments, just as the Quack Doctor, having 

 given a certain dose of Calomel on the same day to 

 a shoemaker and to a tailor, and having found that 

 the shoemaker was badly salivated and that the 

 tailor's gums were not at all affected, jumped to the 

 conclusion that mercury always salivated shoemakers 

 but had no influence whatever upon the constitu- 

 tions of tailors Take, for example, the well known 

 Fire Blight on Pear Trees, which attacks particular 

 trees in particular orchards, apparently iu the most 

 capricious manner. Some years ago a letter was 

 published from a correspondent of the Rural Nrw 

 Yorker, strongly recommending a remedy which 

 he had found effectual on his own trees. In .such 

 a case as this, it ought to have been shown that out 

 of a hundred trees, to which the remedy had been 

 applied, none or next to none had been affected by 

 Fire Blight, and that out of a hundred other trees 

 in the same orchard, which had been left untouched, 

 a considerable percentage had been blighted. I^o 

 such facts, however, were shown in the letter. All 

 that appeared was, that a few trees to which the 

 remedy was applied were not blighted; and even 

 of these, one, if my memory serves me, was said to 

 have been partially blighted. But the remedy 

 itself was so absurd, that it is difficult to see how 

 any sane man could be deluded into trying it. We 

 were to bore an inch augur hole into the trunk of 

 the tree, fill it with ten-penny nails and sulphur, 

 aud then plug it up ; the theory being, as the 

 learned writer assured us, that the iron of the nails 

 combined with the sulphur and ibrmed Sulphate of 

 Iron, and that this Sulphate of Iron was received 

 into the circulation of the tree and cured the Blight. 

 Lnfortunately, however, for the theorist, every che- 

 mist knows that Sulphur and Iron will not, when 

 mixed together, produce Sulphate of Ir(m, any more 

 than Sulphur and Lime, when mixed together, will 

 produce Sulphate of Lime or common Gypsum. 

 Besides, if Sulphate of Iron is a real remedy for 

 Fire Blight, why not purchase it ready-made at the 

 Druggists, and apply it iu the form of a poultice or 

 cataplasm to the external surface of the tree, so as 

 to do away with the necessity for that objectionable 

 one-inch augur hole '( Talk of borers indeed . 

 Why a single one of these gigantic iron-tailed borers 

 ■would ruin a small-.sizcd pear-tree, aud the remedy 

 would be worse than the disease. 



As regards the fallibility of human testimony, I 

 may say that I have more than once tested by ac- 



tual experiment the assertions of men, whom I con- 

 sidered perfectly trustworthy, and who I know^ would 

 uot intentionally deceive, and found those assertions 

 to be utterly -^lusupported by facts. For example, 

 I was once told by a fruit-grower, that he had killed 

 all the plant-lice on his trees by making a dense 

 smoke round them with burning tar on a siill even- 

 ing. I received particular directions how to go to 

 work. I followed tho.se directions in the minutest 

 particulars. And the result was that the plant-lice 

 on a particular bough, which had been envelop- 

 ed in the densest smoke of all and for the longest 

 time of all, were alive and kicking the next da}'. 

 Do I therefore believe that my friend, the fruit- 

 grower, lied '( Not at all. But plant-lice often 

 suddenly disappear in a few days or a week from 

 the action of the numerous parasitic and cannibal 

 insects that attack them His plant-lice were pro- 

 bably about to disappear in this manner, at the time 

 that he smoked them, and mine were not. And 

 hence we can easily explain why the two experi- 

 ments resulted so very differently. 



By way of practical comment upon the foregoing 

 remarks, I subjoin several prescriptions against 

 Noxious Insects, which have been taken at random 

 from various recent publications, with a lew obser- 

 vations upon each : 



To CtJUE WoiiMY TiiKES.— The following recijie is pub- 

 lished in the New York Evening Post: 



With a lai'sc gimlet or augur bore into the body of the 

 tree, just below where the limbs start, in three jilaccs, a 

 groove ineliuing downwards. Witn a small funnel ]iour 

 a shilling s worm of quiclisilver into each groove. Peg 

 it up closely and watch the result. Had it been done 

 when the sap first started on its upward eireuit it would 

 have been more efTieacious — yet, even now, it will greatly 

 abate the nuisance. 



The plan was first tried for a wormy apple tree by Sa- 

 muel Jones, Esi)., of Canaan, Columbia Co , N". Y., and 

 with entire success. It is believed, that, far from damag- 

 ing the trees, it will even add to the beauty of the foliage. 

 In the case of the fruit-tree above mentioned the cure was 

 surprising, not only the fruit becoming perfect and beau- 

 tiful, but the very leaf seemed to grow larger and far 

 more dark and glossy. 



What is a "wormy tree?" Does the writer 

 mean a tree afflicted by borers? Or a tree afflicted 

 by the common "caterpillar," or by some other of 

 the numerous "worms" or lejiidopterous larvaj that 

 infest the foliage of the apple ? Or a tree the iruit 

 of which is infested by the "apple-worm" which is 

 the larva of the Codling'-moth? Before one takes 

 Patent Medicine, one usually likes to know what 

 disease it is intended to cure. As to any effect that 

 crude quicksilver would or could have upon the 

 constitution of a tree, we know that it may be in- 

 troduced into the human bowels in very large doses 

 without affecting the system; while comparatively 

 very minute doses of such chemical preparations of 

 mercury as Calomel or Corrosive Sublimate produce 

 disastrous results Ilencc it is reasonable to infer 

 that crude mercury, when introduced into the trunk 

 of a tree, would be perfectly inert, just as a leaden 

 bullet fired into the trunk of a tree produces no- 

 thing but mechanical injury, while the same weight 

 of white lead would proljably be highly destructive 

 to vegetable life On the other hand no reasonable 

 man can doubt, that it must injure a tree more or 



