The Royal Society of England, with the approval of King Edward, has awarded the Copley Medal to Prof. Albert A. Michelson of the University of Chicago for optical investigation. It has awarded the Davy Medal to Prof. Edward Williams Morley of Cleveland, Ohio, for his investigations in physics and chemistry, and especially for his determination of the relative atomic weights of hydrogen and oxygen. Dr. J. Schubert, of the Prussian Forestry School at Eberswalde, as the result of five years' study of forest influence on rainfall, says that of seventeen gage sta tions in the forest, at the forest's edge, and in the open, the forest stations show the greatest, and the open stations the least precipitation. Corrections for snowfall and for difference in the exposure of the gages as regards wind, amount to 5.5 per cent; the observed difference in catch being 5.2 per cent. San Francisco is suffering from a plague of rats, and is offering a bonus for their destruction. Apart from the general destructiveness of rats, they carry and transmit the bubonic plague, and have often aided in spreading pestilence through Asiatic cities. They are so prolific that any temporary upsetting of the "balance of nature" may result in an enormous in crease in their numbers. The earthquake in San Fran cisco doubtless provided them with innumerable safe hiding places, and in other ways favored their in crease. M. I. St. Murat, director of the Meteorological In stitute of Roumania, publishes the results of his study of the retarding influence of forests on wind velocity in the Annales of the Roumanian Academy. He finds that the greatest effect which a forest can have upon the wind consists in diminishing the wind velocity to leeward of the forest. At 164 feet this decrease in velocity may amount to 4 to 7% miles an hour, which means a reduction of the force of the wind by one degree on the Beaufort scale. This decrease is felt within 330 feet of the forest. After that the velocity increases again with increasing distance, and at about 1,640 feet reaches the force noted before the forest was encountered. An interesting phenomenon recently discovered by Marckwaldt consists of an alteration occurring in the color of a body under the action of light, while the original coloration is re-established in the dark. The substances showing this phenomenon are very few in number, though, according to communication by Prof. H. Stobbe at the recent Congress of German Natural ists and Physicists, the group of fulgides contains a number of substances of this kind. This phenomenon, called phototrophy, is of especial importance for chem ical and physical science, as possibly embodying an im mediate conversion of light waves into chemical en ergy. It might become extremely valuable for photog raphy or for any other art utilizing radiations of a similar nature. Astronomers are uncertain as to whether comets are coming from spaces beyond the limits of our planetary system or from this system itself. While the latter hypothesis seemed to be more plausible, the fact that a few comets show a hyperbolical trajectory (in oppo sition to the elliptical or parabolical trajectories of the remainder) could not be made to agree with it. In a paper recently published, Messrs. Fabry and Fayet (see Revue Scientifique, No. 16) show that the de partures from the elliptical or parabolical shape of the trajectory observed in the case of a few comets are due to the disturbing effects of the planets of our system, especially of Jupiter, whose influence obvious ly is paramount. According to this statement, all the comets that have so far appeared are thus permanent astres "belonging to our planetary system.