Rensselaer Union, Volume 7, Number 19, Rensselaer, Jasper County, 28 January 1875 — Poisons. [ARTICLE]

Poisons.

We noticed, a few weeks ago, the action taken by the American Academy oi Science, at its last meeting, upon the injurious results likely to issue from the free use of Paris green and other poisons in the extermination of insects. The idea was advanced by Prof. Le Conte, and indorsed by the Academy, that the continual and extensive use of mineral poisons, such as at present prevail in the great fight with the potato-beetle, might end in so vitiating the soil as to render it barren, or the poison might even infect the vegetation and make it baleful. In support of this argument, a case was cited where the fumes of a copper-works in Massachusetts had injured the surrounding forests and grass-lands. The discussion has led to the recital of a similar investigation in Europe, which was pursued some years ago. Prof. Freytag, of Bonn, was at one time employed to study the effect upon vegetation of the fumes from two of the largest copper-Works in Europe,-situated in the same town. In his report the professor contended that the ground could not be injured by the smoke from the works, although this contained copper, sulphur, lead, zinc, arsenic, antimony and other metals. He affirmed, also, that plants could not take up these poisons, and showed that healthy cattle were raised in the ~ immediate vicinity of the works. The injury which vegetation might receive from the poisonous fumes, in his opinion, would come from the condensation of the latter by rain, dew, etc., and the deposition of the acid liquor upon foliage, eating and destroying its tissues. Solid particles might also be deposited upon the plants, choking their pores and, in solution with rain, corroding their substance. Animals eating such fodder would fail to obtain nourishment, and, if solid poisons remained on the leaves, would be poisoned. These views, which are entitled to consideration, are in direct antagonism to the theories of Prof. Le Conte and other members of the American Academy. The deleterious effect of poisons in coloring matter is exciting general attention. At the Glasgow Philosophical Society a paper was recently read by Mr. James McFarland, detailing experiments made by him to ascertain the nature of the coloring material in wax tapers. The results of his tests are as follows: White tapers were found to be harmless; little ash. Yellow tapers were also proved 1 armless, being colored with chromate of lead; ash, metallic. Blue tapers, harmless; colored with ultramarine. Red tapers proved highly poisonous, containing 1.93 per cent, of vermilion; slight ash. Green tapers also proved poisonous; color due to arsenic; metallic ash; Quantity of arsenic, about 1 per cent.— Chicago Tribuno. The New York World wants u> know if a man with a cough is not a hackman.