POPULAR SCIENCE MONTHLY.
ying tzu tung which is especially cultivated for this purpose. It is found chiefly in Hunan, Hupeh, and Szochuen. It attains a height of from ten to twenty-five feet. It has large, beautiful leaves, small pink-white flowers, and a green fruit somewhat like an apple. The seeds are large and poisonous, and it is from them that the oil is expressed. The fruit is gathered in August and September. The machinery used for extracting the oil is very rude, consisting of wooden presses with wedges. The oil is usually of a light color, somewhat resembling linseed oil, and emits a nauseous odor. The principal place of export is Hankow, whence in 1895 there were shipped, chiefly to Chinese ports, 38,714,112 pounds, the value of which amounted to $1,162,524.80. The oil is used in the manufacture of paint and varnish, waterproof paper, and umbrellas, and in western China, it appears, for lighting also. The greater part, however, is consumed in calking, for which purpose it is everywhere used in China. In applying it to the bottom of boats it is put on hot, but for parts not commonly submerged it is used cold. The upper part of a Chinese boat is oiled once or twice a month. Soot from the burned oil and nut is also extensively used in making ink.
On the Summit of Mauna Loa.—Dr. H. B. Guppy recently published an interesting account of a three weeks' sojourn on the summit of Mauna Loa. Many curious observations were made. The air was at first highly electrified. A red blanket used by Dr. Guppy crackled under his hands at night, and he could trace letters on the surface in phosphorescent lines with his finger nails. The effects of these meteorological conditions soon showed themselves in the cessation of the action of the skin, in severe headaches and sore throat, in a tendency to palpitation and dyspnœa, and in sleeplessness, general lassitude, and loss of appetite. These symptoms were attributed to the extreme dryness of the air; for, when a short spell of damp weather intervened, most of the unpleasant symptoms disappeared. Another interesting phenomenon was observed every morning and evening. For about twenty minutes after sunrise and before sunset the shadow of the mountain was thrown back against the sky of the opposite horizon. The average range of daily temperature was found to be about twice as great as at the coast. In order to familiarize himself with the crater. Dr. Guppy adopted the method of making a rough plan with a pocket prismatic compass. In some places the lava crust was thin and fragile, and there was always the chance of a sudden fall into a subterranean cavern. His descent into the crater was made on the northwest side. During dry, clear weather smoke is only evident at two places in the crater: one near the center, and the other in the southwest corner from the base of a yellowish cliff, where there are apparently extensive deposits of sulphur. When, however, the sky is clouded, and especially when the air is moist, white vapor may be seen arising from the greater part of the surface of the crater. The explanation seems to be that this vapor is escaping all the time, but is only visible when the air contains a large quantity of moisture. A very large amount of vapor is discharged from the borders of a small crater lying near Pohaku Hanalei, and this is the smoke sometimes observed from the Kona coast. It is probable that the next eruption will occur on this, the south-southwest, slope of the mountain. Strange to say, a considerable amount of insect life was observed. Butterflies, moths, gnats, bees, and house flies were quite numerous, and in noticeably larger numbers when the wind was southerly. No doubt, they had all been brought up to this absolutely sterile region by air currents.
The American Association, 1898.—The officers of the American Association for the Advancement of Science and the local committees are preparing to make the meeting for 1808 of the association, to be held in Boston, August 22d to 27th, which will be its fiftieth anniversary, or jubilee meeting, worthy of the occasion and of the honorable record the association has made for itself. It is realized that the anniversary gives promise of being the most important scientific gathering ever held in the United States. Many foreign men of science have been invited to take part, and many foreign educational and scientific institutions are expected to send delegates, whereby the meeting will be given an international character. Additional interest will be afforded by the meetings of affiliated