According to Dr. Sturges, an English physician, whooping cough is not always to be escaped by preventing contagion, for at a certain age the disposition toward this disease is so great that the child will originate it. He says: "Whooping cough is a nervous disease of immature life, due immediately, like nervous asthma, to a morbid exaltation of sensibility of the bronchial mucous membrane. Although possible in a modified form at all ages, it has its period of special liability and full development simultaneously with that time of life when the nervous system is irritable and the mechanism of respiration diaphragmatic. A child of the proper age with catarrh and cough is thus on the very brink of whooping cough. A large proportion of such children will develop the disease for themselves upon casual provocation, all contagion and all epidemic influence apart." Therefore he does not think contagion plays the important part generally supposed, and the assumption of a specific morbid poison is in his opinion entirely gratuitous. As to treatment he says: "The specific remedies for whooping cough (which have their season and may be said now to include all drugs whatever of any potency) have all of them a certain testimony in their favor. They agree in a single point: whether by their nauseousness, the grievous method of their application, or the disturbance they bring to the child's habits and surroundings, the best vaunted remedies--emetics, sponging of the larynx, ill-flavored inhalation, change of scene, beating with the rod--all are calculated to _impress_ the patient, and find their use accordingly. BRITISH ASSOCIATION NOTES. The committee appointed to test experimentally Ohm's law, that with any conductor the electromotive force is proportioned to the current produced, reports that this law is absolutely correct. If a conductor of iron, platinum, or German silver of one square centimetre in section has a resistance of one ohm for infinitely small currents, its resistance when acted on by an electromotive force of one volt (provided its temperature is kept the same) is not altered by so much as the millionth of a millionth part. This fine result is the more gratifying since Ohm's law is entirely empirical and does not rest at all upon logical deduction. The vast amount of water circulating through the solid earth is shown by the calculations of the committee on the underground waters of the Permian and New Red sandstones. Taking an average rainfall of 30 inches per annum, and granting that only 10 inches percolate into the rock, the supply of water stored up by the Permian and New Red formations was estimated by the committee to amount to 140,800,000 gallons per square mile per year. This rate would give, for the 10,000 square miles covered by the formations, in Great Britain, 1,408,000,000,000 gallons. Only a very small proportion of this amount is made available for the supply of cities and towns.