ana, he found from three to sixteen per cent, of the hogs affected with trichinæ, the number of hogs diseased varying greatly in different localities. 4. That ninety per cent, of the disease produced by trichinous pork appears as gastero-enteritis, diarrhœa, or dysentery, ten per cent, only representing the cases of trichinosis proper.
Penetrating Power of Different Colored Lights.—An experiment was lately made at Trieste, to determine how far lights of different colors penetrate darkness. Half a dozen lanterns with carefully-selected glass, and all furnished with oil and wicks of the same quality, were lighted on the beach, and then observations were made by a party in a boat. At the distance of half a league, the dark-blue lantern was invisible, and the deep-blue one nearly so; hence it appears that blue lights are not adapted for use in lighthouses, or as signals. Of all the colors the green was visible for the longest distance, with the exception of the red, which ranked next to the white in power of penetration. The conclusion is, that only the green and the red are suitable for signals; and the green light the Trieste observers only recommend for use in conjunction with white and red lights, inasmuch as, when viewed from a short distance, an isolated green light begins to look like a white one.
Curious Freak of the Curly-Willow.—The following curious facts are communicated by Dr. S. Lockwood to the Botanical Bulletin: "We have two pendent willows, known as Salix Babylonica (more correctly S. pendula, Mœnch.), the weeping-willow, and Salix crispa, the curly-willow. On the grounds of Hon. E. W. Scudder, Trenton, New Jersey, is a fine specimen of each, the two having a clear distance of twenty-five feet between their nearest branches. The topmost branch of the curly-willow, on the side of the tree next the weeper, is about ten feet long, and six feet thick, and is densely covered with leaves. The curious fact is, that while the rest of this entire tree has the perfect habit of S. crispa, this large branch has the perfect habit of S. Babylonica. The long pendent branchlets, and every leaf, are in all respects those of the weeping-willow. This is true not only of the form and habit of the leaves, but with positive exactness also of the color. The true crispa leaves are a very dark and shiny green above, and almost a chalky white underneath. The pseudo-Babylonica leaves are a pale yellowish-green above, and still paler, perhaps pea-green, on their under sides. I compared them carefully with the leaves of the neighboring Babylonica, and, excepting perhaps that the leaves of the freak were a little the smaller, a fact of no significance, there was no difference whatever. Looking at this great branch, the spectator comes to regard it as a natural graft. This is an utter mistake. It is purely an outcropping of heredity, and is thus an interesting evidence of the identity of species in the curly and the weeping willow. Supposing S. Babylonica to be the ancestor, we have here the long-dormant inherited force asserting itself, and proclaiming the ancient and wellnigh lost parentage of S. crispa. It is observable, too, that the foliage of the branch, thus representing the true weeper, is much more dense than that on the rest of the tree representing the curly-willow. This is the fact respecting these trees everywhere. The curly-willow has this to its disadvantage, its paucity of foliage, so that, in pointing back to its ancestry, it declares the leaf-wealth of the ancient line. As the tree is a very old one, it is significant that this declaration of heredity should appear so late in life."
A Wise Public Benefactor.—In 1868 Sir Joseph Whitworth presented to the British nation an annuity of £3,000 per year, which was vested in the Department of Science and Art, for the purpose of founding scholarships to promote the instruction of young men in the theory and practice of mechanics and the cognate sciences. He has now made over to the public his large landed estates for similar purposes, reserving to himself a life interest. The Department of Science and Art is to hold the estates, subject to the control of Parliament. In commenting upon this munificent action of Sir Joseph Whitworth, the London Times commends his wisdom in trusting Parliament to adapt his endowment to the varying circumstances of successive times. "We have had," says the Times, "abundant
