were eight hundred or nine hundred feet in length, gave different indications as to direction, amplitude, maximum velocity, and intensity; so that, had these instruments been in the hands of different observers, each observer would have given a different account of the same earthquake. Thus, comparing the average maximum velocities at a station, C, on hard ground, with that at a station, E, on soft ground, they were found to be 1:5. The maximum accelerations at these two stations were 1:2·4. It might therefore be concluded that a building at C would withstand a disturbance which would be sufficient to shatter a similar building placed at E.
A committee of the American Society for Psychical Research, of which Josiah Royce, of Cambridge, Massachusetts, is chairman, wishes to collect accounts from trustworthy sources, respecting supposed cases of apparitions of absent or deceased persons, and the communication by them of facts unknown to the person visited by them, or belonging to the future, which are after-ward verified. It would also like to receive accounts of other similar personal experiences which may have been striking enough for the persons concerned to remember, or perhaps record. The committee's purpose is to collate and examine the evidence presented, with a view to drawing such conclusions from it as may seem proper and warranted. The committee's circular, which may be obtained on application to the chairman, contains a full statement respecting the kind of information it seeks, with a schedule of questions which may be useful as a guide in making up the accounts.
The summer courses in chemistry, to be given at Harvard University this year, will open July 5th and close August 14th. Instruction will be given under the direction of Dr. A. M. Comey in general chemistry, qualitative analysis, organic chemistry, and mineralogy. The fee for any of these courses is twenty-five dollars, and material and apparatus usually cost from five to six dollars additional. It is desired that applications for desks in the laboratory be made before June 15th. These courses are taken each year by teachers, both male and female, who are preparing to teach chemistry, by persons who intend to use their knowledge in the arts, and by general students.
Wood-oil is now made on a large scale in Sweden from the refuse of timber-cuttings and forest-clearings, and from stumps and roots. Although it can not well be burned in common lamps, on account of the heavy proportions of carbon it contains, it furnishes a satisfactory light in lamps especially made for it, and in its natural state is the cheapest of all illuminating oils. Thirty factories produce about 40,000 litres of the oil daily. Turpentine, creosote, acetic acid, charcoal, coal-tar oils, and other useful substances, are also obtained from the same materials as is the wood-oil.
M. H. Fayol reports that a number of oaken piles which have seen nine years of service at Mières, Spain, have taken on the appearance of stone-coal. The structure resembles that of a fibrous coal composed of bright particles separated by dull ones; it also feels like stone-coal. M. Renault states, after a microscopic examination, that the wood of fibers and parenchyma have preserved their characters, and the dottings of the vessels are perfectly clear. Chemical analysis gives a composition analogous to that of lignite. The very black color is ascribed to the presence of tannate of iron.
M. Chevreul gave joy to the members of the French Academy of Sciences by resuming his seat among them on the 5th of April, after a few weeks' absence on account of illness. He seemed only slightly weakened, but was otherwise in his usual vigor. The President of the Academy gave him a suitable welcome, and he replied, speaking till he was checked by Dr. Vulpian, his titular physician.
Dr. Charles Osten records, in "The Practitioner," the case of a woman patient who was made sick by eating eggs. She appears to be affected with a family idiosyncrasy against eggs, for she said that they never agreed with her when well; and neither her mother nor grandmother could eat them.
According to Professor Virchow, the German Colonial Society has had circulars sent to all European colonies situated in the tropics, requesting observations to be made regarding the question of the acclimatization of Europeans in the tropics, in order that the answers may be ready to be communicated to the German Naturalists' Association at its meeting in September next. An exhibition of objects required in fitting out scientific travelers for their journeys will also be held at the same time with the meeting of the Naturalists.
Herr L. Rutenberg, of Bremen, has presented the Natural History Society of that city with the sum of £2,500 for a Rutenberg fund, in commemoration of the services rendered to science by his son, the traveler, who was murdered in Madagascar.