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430 animals. They love to learn, and the imitative instinct natural to them permits them to execute all sorts of feats with agility. They learn tricks more readily than dogs, and, although not manifesting so hearty good will toward the public, execute them with marvelous agility and grace. At Hagenbeck's establishment in Hamburg, where two hundred monkeys enjoy complete liberty of play in the great rotunda, they are given multitudes of children's toys, balls, hoops, wheelbarrows, joiner's benches, etc., and learn to manage them all without any one showing them how. In the center of the rotunda is an immense grain hopper, from which the seeds, corn, walnuts, chestnuts, apple quarters, etc., run into a trough when a wheel at the top is turned. The management of this hopper did not have to be explained to our friends the monkeys. While one of them turns the wheel, the others, sitting around the trough, enjoy the delicacies as they come down, till the one at the wheel, thinking his turn has come, stops, gives the signal for some one to take his place, and comes down to get his share. What other animals are capable of so intelligent an initiative?

Minute Earthquakes.—Very delicate experiments have been instituted by Prof. John Milne to determine the stress inflicted upon the earth's crust by small, even minute, disturbances, whether local earthquakes on a small scale, faint echoes of more violent distant disturbances, those arising from meteorological causes—which are receiving special attention—or even those which are due to the falling of rain and to dew. A shower of rain or a deposit of dew represents a considerable load on the soil, which may perhaps be regarded, in the first instance, as uniformly distributed, but which will probably, because of inequalities in evaporation, not remain so long. The ground on the east side of a building will be more quickly dried than that on the north; the dew on the east side will evaporate before that on the west side, and so on. Thus there will be bending stresses in the soil tending to tilt buildings or piers for instruments that have not deeplaid foundations. Tilts due to rainfall would be irregular; those arising from dew would show a diurnal period. The inquiry is made whether these tilts are large enough to affect astronomical observations. Diurnal oscillations of several sections of an arc have been detected by seismographs in Japan, which Prof. Milne attributes to the evaporation of dew. At the observatory of the University of Oxford a disposable weight, consisting of a crowd of human beings, was utilized. Formed into a solid square, they were marched back and forth, to and from the observatory wall. They were then spread out so that they only touched by the finger tips; and again so as to cover four times the space of that formation. This was supposed to represent the evaporation effect. Seventy-six persons were thus employed, and their marching back and forth produced an appreciable bending of the earth. As an aid to his research. Prof. Milne has had a horizontal pendulum set up in the Isle of Wight, in order to obtain a continuous automatic record of such disturbances as are there manifested.

Improvement in Antitoxine-Making.—In a recent number of the Archives des Sciences Biologiques issued by the Imperial Institute of Experimental Medicine at St. Petersburg is an important announcement by Dr. Smirnow, describing a new method of obtaining diphtheria antitoxine. Hitherto the preparation of the antitoxine has not only involved great expense, but also much time, several months oftentimes. The new method announced by Dr. Smirnow institutes a great saving in both time and expense, and consists simply of electrolyzing a virulent diphtheria broth culture, which is then found to contain an antitoxine of great power and efficacy. Dr. Smirnow states that a dog weighing from eighteen to twenty pounds, inoculated subcutaneously with 0·5 cubic centimetre of a virulent diphtheria broth culture, usually dies in two or two and a half days. If, however, even one day after inoculation, treatment with the new serum is begun, from three to five cubic centimetres of the latter suffice to save the animal.

Maxims for the Holiday.—The first requisite to the complete enjoyment of a holiday, as laid down by the London Lancet, is to have earned it. Only a true workman thoroughly enjoys his season of rest, while the idler, the trifler, the man of pleasure,