will permit. These investigations are expected to be made with critical and scientific accuracy, and will consist in the minute analysis of a somewhat limited number of specimens, and the precise determination of mechanical and physical properties, with a view to the detection and enunciation of the laws connecting them with the phenomena of resistance to flexure, distortion, and rupture.
The Board will be prepared to enter upon a more general investigation, testing such specimens as may be forwarded to the President of the Board, or such as it may be determined to purchase in open market, immediately upon the completion of the apparatus ordered, at which time circulars will be published giving detailed instructions relative to the preparation of specimens for test, and stating minutely the information which will be demanded previous to their acceptance.
The following is a list of the subjects to be investigated by the standing committees, as given in the circular issued by the Board: Abrasion and Wear; Armor-Plates; Chemical Research; Chains and Wire Ropes; Corrosion of Metals; Effects of Temperature; Girders and Columns; Iron, Malleable; Iron, Cast; Metallic Alloys; Orthogonal Simultaneous Strains; Physical Phenomena; Reheating and Rerolling; Steels produced by Modern Processes; Steel for Tools."
Insulation of Lightning-Rods.—We take from the Journal of the Telegraph a few valuable observations on the subject of lightning-rods. The insulation of lightning-rods, says the Journal, is a grave error, because the insulators to some extent arrest the flow of currents of rarefied electricity, which it is the true function of the lightning-rod to facilitate. On the other hand, the insulator amounts to nothing as a barrier against a discharge of lightning, which can either pass through it or leap the short distance between the rod and the building. The prejudice in favor of insulators arises from a misapprehension. Strictly speaking, there are no non-conductors; but that term is applied to substances which conduct very imperfectly and are subjected to violent disruptive effects when a shock of electricity passes through them. To prevent a discharge from leaving the rod and passing through the building, something more must be done than to attempt to keep it out by erecting such flimsy and insignificant barriers as insulators. The rod must be arranged so as to present points for the reception and discharge of electricity at the extremities of the building, both above and below, and the different terminations in the ground must be connected by rods lying across the roof, so that lightning can be provided with a path in an horizontal direction, which, being continuous, will be preferred to any series of detached masses of conducting matter contained within the building.
Action of Absinthe and Alcohol.—In an essay which received a prize from the French Academy of Sciences last December, Dr. Magnan states as follows the comparative action of absinthe and of alcohol: Whether injected into the stomach, pulmonary passages, cellular tissue, or vascular system, these two agents produce different effects. Essence of absinthe, in weak doses, causes vertigo and sudden contractions in the muscles of the anterior portion of the body; in strong doses, epileptic attacks and mental disorder. The well-known effects of alcohol are muscular debility, staggering, relaxation of the limbs, and finally comatose sleep, without any epileptic symptoms. Injected simultaneously, alcohol and absinthe, instead of neutralizing, intensify one another, and the absinthine phenomena are in part masked under the alcoholic. The substances used in the manufacture of the liqueur absinthe, viz., the essences of anise-seed, angelica, sweet-flag, marjoram, fennel, mint, possess no toxic action. Hence all the injurious effects of the liqueur are due purely to the wormwood. Epileptiform symptoms never follow from the use of alcohol, and they are characteristic of absinthe.
Fish-Life and the Pollution of Rivers.—The injurious effects on fish of the pollution of rivers with the refuse of gas-works have been very thoroughly investigated by Prof. A. Wagner, of Munich, and from his report on the subject we take the following account of some of his experiments. His method
