Page:Popular Science Monthly Volume 56.djvu/638

622 Fla., which runs only during about three months in summer and is dry the rest of the year, thousands of a large colony of Unio obesus may be found just buried in the sandy banks or among the flags and rushes of the bottom, where there is very little moisture, all in healthy condition. Mr. Simpson has laid these mussels in the sun for months without killing them. The specimens which live in perennial water seem to die soon if removed from it, while those which inhabit streams or ponds that often dry up will live a long time out of water. Some species in rocky streams live in the crevices of the rocks. In the Big Vermilion River, in La Salle County, Illinois, a swift, rocky stream, the author has found living mussels that had been so washed about that nearly all the epidermis was destroyed. The shells in such streams are usually heavier than those in more quiet water.



of the University of Chicago, has made two excursions to Mexico for the purpose of establishing the physical types of the aborigines by means of measurements, photographs, and casts. He studied twelve tribes, half of which were almost unknown to science, and made measurements of more than eleven hundred and fifty men and three hundred women. On his last trip he rode one thousand miles among the mountains on horseback. In a recent paper in the Open Court he takes notice of frequent and curious survivals of pagan belief to be remarked among these peoples, although they are all supposed to be devout Christians. In one instance, which is specially described, an idol bearing some resemblance to those found among the ruins of the ancient cities occupied a station in the church by the side of the crucifix, sharing the honors with the statue of the Virgin on the other side. Grief and consternation prevailed among the Indians when the idol was taken away by the ecclesiastical authorities.

question of the increase of insanity in England during the last few years is regarded as assuming a serious aspect, and the report of the Commissioners of Lunacy for 1898, showing the largest annual increase yet recorded, the Lancet says, reveals the gravity of the situation. Other collateral facts given in the report "add to the seriousness of the outlook." The increase in the number of inmates in institutions for lunatics is attended with a falling off in the recovery rate, which is lower for 1898 than that of the previous year, and even than the average of the last ten years. A steady diminution in the recovery rate has appeared also during each period of five years since 1873. The attempt to account for the increase of lunatics in public and private asylums by supposing that it is made up by removals thither from workhouses or from the care of relatives fails, for it is shown that this class of insane is increasing too, though slowly. The subject is regarded as of so much importance that it was considered and discussed in the Psychological Section of the British Association at its Bristol meeting in 1899.

by which calcium carbide can be continuously produced more cheaply than by the process at present in use is reported, in Industries and Iron, to have been discovered by Professor Freeman, of Chicago. In the new process a huge arc lamp inclosed in brickwork in the interior of a furnace is employed. The upper electrode of the lamp is hollow, and through it is fed a powder composed of common lime and coke. This powder, being carried through the upper carbon directly into the electric flame, is melted by the intense heat, and molten calcium carbide runs away from the furnace. It is estimated that the carbide is produced at a cost of half a cent per pound.

method of securing more perfect combustion, described by Mr. Paul J. Schlicht before the Franklin Institute, is based on the fact, described by the inventor, that if a current of air is properly introduced into a chimney flue through which hot products of combustion are escaping, it will flow in a direction contrary to theirs, and, becoming heated in contact with them, will reach