Page:Popular Science Monthly Volume 30.djvu/147

Rh Arsenic In Wall-Papers.—Professor H.Carmichael presented some important facts to the American Association in his paper on "The Quantity of Arsenic contained in Wall-Papers." Scientifically speaking, he said, probably no paper in the market is strictly free from arsenic, for faint indications of it may always be discovered when specially delicate tests are applied. For the present purpose, papers containing less than one fiftieth of a grain of white arsenic to the yard are said to be free. Thirty-one samples of paper, which were regarded as average ones, yielded on analysis an average of 2-2 grains to the square yard. It was impossible to classify the papers so that their prevailing colors would bear any simple relation to the amount of arsenic discovered. A paper with green ground, in which arsenic might have been suspected, was the only one in the lot entirely free therefrom, while a paper nearly white contained a quarter of a grain. Papers "warranted strictly free from arsenic" by the manufacturers also contained notable quantities. In general, arsenic is more abundant in the figure than in the ground, and in brilliant than in the light, monotoned papers jus-now in fashion. Carmine red is particularly distinguished by the amount of arsenic which it usually yields. This is to be attributed to the arsenic employed in the manufacture of aniline red, the common red coloring-matter of paper, and from which, in its manufacture, the aniline fragment is imperfectly freed. This same red dye, with its arsenical impurity, is unfortunately largely employed, on account of its resemblance to the more costly cochineal, in coloring worsted and woolen underwear. It may be easily distinguished from the latter by the readiness with which it imparts its color to wash-water or the skin with which it comes in contact. Unfortunately, there is no guide in the selection of papers free from arsenic except chemical analysis, and no security to the purchaser unless by a prohibitory law duly enforced.

The French Association.—The French Association for the Advancement of Science met in its fifteenth annual session at Nancy, August 12th, and was opened with an address by the president for the year, M.Friedel, the chemist, whose subject was "The Progress of Chemistry and Mineralogy." M. Friedel preceded his address with the announcement that the negotiations for a union with the Association Scientifique, had been brought to a happy conclusion, and only a single detail of formality had to be gone through to make the union an accomplished fact. The object of the Association was defined to be, to attract the largest number possible of their fellow-citizens to high scientific culture; not to vulgarize science, or bring it down by taking its true character away from it; but to unite those who cultivate the highest science, and group around them those persons who, without ascending to the summits, wish, at least, from medial regions, to follow with their eyes the traveler going up, through the obstacles, from peak to peak, without ever reaching the last one. In his conclusion, he recommended as another purpose, which they could all seek without provoking jealousies, the advancement of the intellectual and moral glory of their country. "Science," he said, "is a marvelous agent of industrial progress, and those labor under a false inspiration who regard it as a superfluity of an aristocratic civilization. Economic failures must soon remind them that the industry of routine has now lived its day, and that that only is vital which rests closely on the knowledge of the laws of matter. Science is no less favorable to moral development. How the assiduous search for truth, whether in the world of matter or in that of extent and quantity, elevates the mind and fortifies the heart! How much ought the comparison of the little that we know with the infinitude that we do not know to contribute to make us modest! "Another advantage of helping the progress of science is that, while we differ on so many other questions, we can be one in that. M.Collignon, the secretary-general, made the annual report of the history of the Association during the year. An address of welcome was made by the Mayor of Nancy, who said that they desired to create there a great center of French science, to compensate for what they had lost at Strasburg. An important discussion took place, in the Agricultural Section, on wheat-production, in which the competition of India was acknowledged to be formidable, and threatening to become