This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Most gardeners look upon the Nettle as their enemy, and hence it has been driven forth into by places, or waste land, or the shadow of hedgerows. Nevertheless its fibre makes good linen as the Dutch have found; the leaves when young are a delicate esculent; horsedealers use the seeds to give their cattle spirit and a fine skin; and finally the roots when boiled with the addition of alum and a little salt form a good yellow dye. Thus it appears that every part of a Nettle may be usefully employed in rural economy or in art. Horned cattle find it a safe and sound food, for it is early and easy to grow; the worst soils suit it; it requires no care, will bear any kind of weather, and propagates itself. It may be cut five or six times a year; and in the spring, when cattle want food, it supplies them with it abundantly. It may be cut young, and given green; or it may be left to stand longer for hay; but in the latter case it must not stand too long, or cattle will not eat its coarse haulm. - French Paper.
An inquiry instituted by the Belgian government merits attention. For some years, a notion had grown into a belief that certain manufactories were prejudicial to health and vegetation, and so much disquiet arose thereon, especially in the province of Namur, that the governor reported it to the home department at Brussels. A commission was appointed, two chemists and two botanists, who, commencing their inquiry in June, 1855, pursued it carefully for several months, confining themselves to factories in which sulphuric acid, soda, copperas, and chloride of lime were made. The two chemists watched the processes, and noted the escape of gases from the chimneys. They consider soda factories to be the most noxious, and tall chimneys more hurtful than short ones, because of the greater surface over which they diffuse the vapors; and tall chimneys, by quickening the draught, discharge gases which otherwise would be absorbed in the passage. Hence, contrary to the commonly received opinion in this country, they hold that there is less dispersion of deleterious vapors with a short chimney than a tall one.
The botanists on their part show, as might be anticipated, that the effect on vegetation is most shown in the direction of the prevalent winds, and more during rains and fogs than in clear weather. They establish beyond a doubt the hurtful influence of smoke, due to the presence of hydrochloric and sulphuric acid, and they find that the greatest distance at which the mischief is observable is two thousand metres (a little over an English mile); the least six hundred metres. They enumerate thirty-four kinds of trees which appear to be most susceptible of harm, beginning with the common hornbeam (Carpinus Betulus), and ending with the alder; and between these two occur, in sequence, beech, sycamore, lime, poplar, apple, rose, and hop. As regards the effect on the health of men and animals, the commission find the proportion of deaths per cent to be lower now in the surrounding population than before the factories were established: from 1 in 58 it has fallen to 1 in 66. One reason for this improvement may consist in the better means of living arising out of the wages earned in the factories.
However, the commission wind up their report with an assurance that health, either of men or horses, suffers nothing from the factories, and vegetation so little, that farmers and graziers may dismiss their fears, and the government refrain from interfering.
An ingenious mode of rearing birds is practised in France. The young birds with the nest are placed in a small cage, and tied up near the place in which the nest itself lay. I have seen the old birds come and attend to the nursing of their offspring in this way with the utmost zeal and success. When we consider how much more skillful they are in finding the best food, and administering it in the best manner, we cannot be surprised that in this way the great losses, otherwise sure to occur, are avoided.
In France, M. Beelard has made some curious experiments on the Influence of Light on Animals, and finds that those creatures which breathe from the skin, and have neither lungs nor branchiae, undergo remarkable modifications under different colored rays. He exposed the eggs of flies (Musca carnaria) under bell-glasses of six different colors: little maggots were hatched from all; but those under the blue and violet rays were more than a third larger than those under the green. Frogs, which by reason of their naked skin, are very sensitive to light, give off half as much more carbonic acid in a given time under the green ray as under the red; but if the frogs are skinned, and the experiment is repeated, the excess then is with those under the red ray. Frogs placed in a dark chamber lose one-half less of moisture by evaporation, than when placed in common daylight.