THE A:N^NUAL meeting. 139 



Mr. Haufoi'd had tried this solution with no satisfactory results; but the 

 linseed oil remedy had been very effective with him. 



The exercises of the morning closed with a short paper written by Prof. T. 

 J. Wramplemeier, of the State University, upon 



POISONS AND THEIK USE AS INSECT EXTEBMINATORS. 



By far the most common insecticides used by the agriculturist are those 

 compounds of arsenic, Paris green and London purple, with the former of 

 which at least, you are well acquainted. Besides its use for the destruction of 

 the potato beetle, Paris green is highly recommended to be used against the 

 apple coleophora, the juniper web-worm, the elm-leaf beetle, Chapin's apple 

 leaf-sewer (Dept. of Agric. Eeport, 1878), the army worm (Rep. of Entomol- 

 ogist, Dept. of Ag., 1879), and a number of other insect pests. 



London purple is a dry product obtained in the manufacture of aniline 

 colors. It is composed mostly of arseniate of calcium. (Report of the Chem- 

 ist Dept. of Ag., 1878, p. 144.) It is much cheaper than Paris green and can 

 be used wherever that substance can be used. It has been found by experi- 

 ment that weight for weight it is more efficacious than Paris green. Indeed, 

 Prof Riley says that a given weight will go twice as far as the same amount of 

 the green. (Amer. Naturalist, 1881, Oct., p. 821.) It occurs in much finer 

 powder than Paris green, hence can be more readily suspended in water or 

 more intimately mixed witli diluents in the dry state than the former. Prof. 

 Eiley recommends the proportions, one pound to 3G pounds of the diluent in 

 the dry state, or one-half pound in about 50 to 55 gallons of water. (Bulletin 

 No. 3, U. S. Ent. Com'n, 1880.) Its color is also an advantage, as it not only 

 colors the ingredients with which it is mixed, but is more readily seen on the 

 plants than Paris green. 



Other salts of arsenic as well as arsenious acids are used and largely form 

 the basis of the patented insect poisons. The objections to the use of these 

 other compounds of arsenic are : I, Their white color, on account of which they 

 can more easily be mistaken for harmless material ; and 2, The strength of 

 each has to be determined by experiment, and unless used in the proper 

 dilution they are liable to injure the foliage. 



Not a little has been said and written about the danger attending the use of 

 arsenicals. Their highly poisonous nature of course necessitates their being 

 used with the greatest precaution. Whenever there has been a case of poison- 

 ing it has been explained as due to accident or gross carelessness. In a case of 

 poisoning by arsenic the best antidote is ferric hydrate, or as it is more com- 

 monly called, hydrated peroxide of iron, in the condition of moist precipitate. 

 This must be freshly prepared in order to be most effective and can be obtained 

 of any druggist. While waiting for this give the patient an emetic, as for in- 

 stance, a teaspoonf ul of mustard in warm water. The hydrate should be given 

 then in doses of a tablespoonful. As to the effect of these poisons on the land, 

 it has been pretty well established that their use in such small quantities and 

 in such finely divided state may be continued for years, even centuries, without 

 giving cause for alarm. 



The use of white hellebore, either as powder or suspended in water, and 

 which is so highly recommended for the destruction of the currant worm, 

 (Mich. Board of Ag. Report, 187C, pp. 170, 173), appears to be attended with 

 no especial danger. Though it contains the poisonous alkaloid veratria, it is in 



