THE LANCASTER FARMER. 



[January, 



PARIS GREEN. 



As the discussion on tliis subject, wliich 

 was going on last summer and which unsettled 

 the minds of many timid iicople,' has now 

 partially subsided, and in order to inform our 

 readers in advance, how far our own recom- 

 mendations have been justified by the opinions 

 and experience of what we deem competent 

 autliority, we publish the following excellent 

 article from the New York Scmi-ired-ly Tribune 

 of December 28, 1875. We do this the more 

 readily, because two years ago we were com- 

 pelkd to investigate a report that a whole 

 family in the city of Reading, Pa., had been 

 poisoned by eating Paris-greened jiotatoes, 

 and when, by the assistance of Mr. Herman 

 Strieker, of that city, the case was finally 

 "holed," it was found to be clearly "bosh," 

 without any foundation in/«r; whatever. 

 Paris Green as an Insect Destroyer. 

 The readers of the agricultural department 

 of the 7'rihiM will rtmtmber that about a year 

 ago the value of Paris green as an insecticide. 

 and especially as a n medj-.against the ravages 

 of the Colorado potato-beetle and the cotton 

 worm, was fully discussed in the se columns. 

 80 far as past t xiierience and the facts, at that 

 time known, pennittid, its influence on the 

 plant, on the soil, and on man, either indirectly 

 through the soil or through the plant, was 

 considered ; the conclusion arrived at being 

 that, used with ordinary caution and judgment 

 it was a valuable and safe remedy. This had 

 long been the conclusion of practical men in 

 the Mississipjii Valley who had used it exten- 

 sively ; but the ijutstion was opened again by 

 a paper read by Dr. J. L. LeConte, of Phila- 

 delphia, before the National Academy of 

 Science, which paper, from the theoretical 

 side, strongly condtmned tlie use of the poison 

 for the pur] osts nitntiontd, and which natur- 

 ally attraetid considerable attention and wa^ 

 barpid upon by the manufacturers of "potato 

 bug machines," or their glib agents. The 

 National Academy, after the reading of Dr. 

 LtConte's paper, ajipointed a ccmmittce to 

 "investigate and report upon the subject of 

 the use of poisons applied to vegetables, or 

 otherwise, for the destruction of deleterious 

 insects and other animals," etc.; but that 

 ccmmittee has, I believe, made no report yet. 

 Prof. E. C. Kedzie, of the Michigan Agricul- 

 tural Cejllege, has, heiwever, bttn carrying on 

 a series of interesting experiments during the 

 summer, and while visiting the college last 

 August I had the jileasure of witnessing and 

 makinguotesof the professor's operations. As 

 he lias since given these results to the Ameri- 

 can Public Health Association, and jiublished 

 an abstract of them in the Deln H Free Press, 

 I take the liberty of gi'ving them wider circu- 

 lation. 



First, as to the use of the mineral for the 

 Doiyphora. Does Paris green poison the 

 tuber y Tubers taken f n m vines that had 

 been repeatedly dosed with the ordinary mix- 

 ture—as much Paris green, in fact, as they 

 would bear— gave no trace of arsenic. Ee- 

 garding the idea, which has been suggested, 

 that the use of the jioison rendered the tubers 

 watery and waxy, the conclusion is that such 

 condition is brenight about by the .stunted 

 growth and destruction e)f the vines caused by 

 the insect, which thereby prevents maturity 

 of the tuber. Does Paiis green poison the 

 land ? This is meant, of course, in the sense 

 of rendering the lard unfit for the growth of 

 crops; and Preif. Kedzie justly consideis not 

 only its immediate I ut its remote effect. Theo- 

 retically, one would naturally infer that Paris 

 green is converted into an insoluble jireci])i- 

 tate or salt with the hydrated oxide of iron 

 which exists in most soils ; but not resting the 

 matter on theoretical or abstract reasoning, 

 Prof. Kedzie made careful tests and experi- 

 ments. He passed a solution of arsenious tri- 

 oxide through common garden soil, and fil- 

 tered Paris green in a solution of hydrochleiric 

 acid through dry earth. In neither case 

 could any poison be detected in the filtrate by 

 the severest tests. Soil taken from a field of 

 wheat that had been sown with Paris green 



at the rate of five pounds to the acre, showed 

 no trace of the poison when submitted to any 

 or all e)f the tests which the soil would get by 

 natural .solvents in the field, but distinctly 

 showed the arsenic when treated with dilute 

 sulphuric acid. The Paris green was sown on 

 the ground early in spring, and was thick 

 enough to give a very distinct green tint to 

 the surface. The grain and the straw were 

 submitted to careful chemical examination, 

 as wcie also cabbages grown in soil that had 

 the year before been in potatoes and received 

 a heavy siirinkling eif green. No trace of the 

 pe.ison was tbunel in cither, and it was ob- 

 served that the chipmueks ate large quantities 

 of the grain without injury. The more prac- 

 tical conclusions from Prof. Kedzie's experi- 

 ments may be thus summed up : 



1. Paris green that has been four months in 

 the soil no lemger remains as such, but has 

 passed into some less soluble state, and is uu- 

 affected by the ordinary solvents of the soil. 



2. When applied in small eiuantities, such as 

 alone are necessary in destroying injin-ious in- 

 sects, it does not afi'ect the health of the plant. 



3. The power of the soil to hold arsenious 

 acids and arsenites in insoluble form will pre- 

 vent water from becoming poisoned, unless 

 the green is used in excess of any rtciuirement 

 as an insecticide. 



These experiments of Prof. Kedzie's accord, 

 so far as they refer to the influence of Paris 

 green on man thre^ugh the plant, with others 

 by Prof. McMurtrie, of the Department of 

 Agriculture, which showed that even where 

 the green was applied to the soil in such 

 quantities as to cause the wilting or death of 

 the plants, the most rigorous chemical analysis 

 could detect no trace of arsenic in the conipej- 

 sition of the plants themselves. They also 

 fully bear out the opinions which I have al- 

 wajs held, and justify the advice w hich I have 

 given. 



Before leaving this subject of remedies for 

 the Colorado potato-beetle, it may be well to 

 say a few words about two other compounds 

 that have been strongly recommended and ad- 

 vertised as such. The most notable of these 

 is that advertised as " Potato Pest Poi-'on" 

 by the Ledi Chemical "Works of Ledi, N.J. 

 It is put up in pound packages, which are sold 

 at $1 each, with directions to dissolve four 

 otmces in two ejuarts of hot watei', then i)our 

 into a barrel containing 80 gallons of cold 

 water, and use on the vines in as fine a sjiray 

 as possible. Analysis shows it to be com- 

 posed of one part pure salt and one lart of ar- 

 senic (arsenate of copper), and it has the gen- 

 eral color and appearance of ccmmon salt. 

 Early in September, during epiite hot and dry 

 weather. I had this poisem tested in a field of 

 late potatoes belonging to Mr. W. Hinterthur, 

 of La Clede, Mo., the field having been badly 

 infested during the summer, but about half 

 the vines having been saved by pretty con.staut 

 hi nd-pie-king. These were at the time fairly 

 covered with the insect in the egg, larva, and 

 beetle states. Five rows were treated with 

 the poison, both according to directions and 

 by finely sprinkling the dry powder over the 

 vines. As soon as the peiwder touched the 

 larva?, they writhed and became restless as 

 with pain, the powder dissolved and formed 

 a translucent coating upon them, and in about 

 three hours they began to die. The beetles 

 were not so easily affected, tl ougli they too 

 were in timekilleel by it. Used as directed, it 

 destroys, but hi.rdly as efficiently as the ordi- 

 nary Paris gieen mixture. A pound of Paris 

 green, costing much less than a pound of the 

 Lodi ]ioiscn, will go nearly as far in protect- 

 ing a field of potatoes, arid I cannot see any 

 advantage to a farmer frem the employment 

 of a patent poisonous compound of the nature 

 of winch he is ignorant when a cheaper one is 

 at hand. The color of the Lodi poison is also 

 very objectionable, as there is much more 

 danger in the use of poisons when their color 

 renders them undistinguishablefrom ordinary 

 salt. The other powder is one prepared by a 

 gentleman in Philadelphia, and strongly re- 

 commended as a "potato-bug remedy." It 

 was given to me by Dr. J. L. I.e Coute for 



trial. It is a dull, yellowish powder, which, 

 when analyzed, proves to be crude "flowers 

 of sulphur," containing 95 per cent, of sul- 

 phur and 5 per cent, of impurity and coloring 

 matter, such as yellow ochre, sand, etc. A 

 thorough trial on the potato patch above men- 

 tioned showed it to be entirely worthless. In 

 conclusion, the fact that Paris green, cau- 

 tiously handled and judiciously used, is an ex- 

 cellent and cheap antidote to the ravages of 

 the Coleirado potato-beetle cannot be too 

 strongly urged. That it is usefid against some 

 other insect pests is also true ; but it is some- 

 times recommended for suctorial insects, 

 which it will not afliect as it does those which 

 masticate, and its too general use should be 

 opposed. In an emergency it may be used 

 against the canker woim, as J. B. Upson, of 

 Reickford, 111., (Weekly SVj^kiic, June 2, 1875) 

 and others have shown. Yet I cannot recom- 

 mend it in such a case where other available 

 preventive means are at hand— means which 

 are as simple as they are dangerless. — Prof, 

 a Y. Biky. 



SELECTION AND CHANGE OF SEEDS. 



AVe commend the remarks of our veneralile 

 correspondent, J. B. Garber, esq., to the can- 

 did considerations of our agricultural friends, 

 based as they are on close observation, and a 

 lemg life of practical experience. We believe 

 that " in-and-in-breeding " of live stock is gen- 

 erally considered deteriorating, and therefore 

 that the crossing of breeds at certain intervals 

 tends to their improvement. It is not sure, 

 however, that this law obtains to the same 

 extent in the vegetable kingdom. From our 

 own observations and the experiences of prac- 

 tical agriculturists, we would repose more 

 cemfidence in judicious and thorough "selec- 

 tion," than in an entire change of seed. The 

 experiments with foreign seeds in this coun- 

 ti y, in our view, have been anything l)ut suc- 

 cessful in a general sense. Perhaps if more 

 attention had been paid to proper selection, 

 backed by thorough culture and judicious 

 manuring, the results would have been more 

 fitvorable. Even in many cases where the 

 change of seed has seemed to produce a good 

 efi'e ct, it has been merely a spasmodic result, 

 attributable more to a favorable condition of 

 the season and other latent unknown causes, 

 than to a change in seed ; and, in another 

 season and under diflerent circumstances, 

 things have relapsed into their former condi- 

 tion. A single experiment, on either a small 

 or a large scale, is not always sufticicnt to de- 

 teimint'^ such a question. Indeed, we are of 

 opinion that in experimental agriculture, no 

 greater mistake s have been made than those 

 wliie-h estimated general results on the effects 

 of special and limited exj'criments. If one 

 hill jiioduccs a hundred potatoes it does not 

 by any means indicate that ten hills will pro- 

 eluce a thenis and— imless they are so far sep- 

 arated tliat eme cannot by any means absorb 

 the elementary substances due to another. 

 Neither will a popular furore determine' the 

 result, because the people scraetimes become 

 psyche)logised on these questions, and rush 

 pell mel! into new experiment sand enterprises, 

 with.out thoroughly examining the premises. 

 Still, with all this. 'tl ere jjioi/becasesin which 

 the change of seeds alone, have produced a 

 desirable effect, (see Dec. No., p. 187, col. 11 

 and yet, even crofsivy may be of no account 

 in its continuous results, if no regard is paid 

 to subsequent care ful selection. 



We are compelled to defer to our February 

 numVicr several japers that otherwise would 

 have ajipeared in this number. Therefore, 

 those of our correspondents who do not see 

 their ccmniunicationsor contributions in print 

 the present month, will please attribute it to 

 a want of room. "First cc me, first served," 

 is a rule we usually adopt unless in cases, the 

 pulilication of which will not admit of a post- 

 pone mcnt. We hope, therefore, our friends 

 will ne)t abate their zeal to make The Fah jieb 

 throughout the Centennial year, a faithful ex- 

 ponent of the state of husbandry as it exists in 

 the great county of Lancaster in 1876. 



