Page:Popular Science Monthly Volume 30.djvu/882

From Wikisource
Jump to navigation Jump to search
This page has been validated.
858
THE POPULAR SCIENCE MONTHLY.

call faults, in which the "throw" or displacement sometimes amounts to many thousand feet. Earthquakes, mountain-chains, and volcanic eruptions may all be considered as consequences of this readjustment. It is evident that the folds and fractures seen in every mountain-belt could not have taken place without great disturbance of the surrounding country; and as they have been formed, not all at once, but each by itself, and each one by many paroxysms, an almost infinite series of earthquakes is recorded in the structure of every mountain-chain. The lines of fracture which are marked by mountain-chains are ever, after the first disruption, lines of weakness, where the resistance to lateral pressure is diminished, and where the strain of large unbroken areas is relieved from time to time by displacements, necessarily attended by earthquakes. So along up the Atlantic slope of the Alleghanies there have been many earthquakes since the country was occupied by the whites. Not a year passes that we do not hear of several in New England, the Middle, or Southern States. As the population increases, the number of observers is multiplied and the number of structures liable to damage constantly added to; so that such phenomena now attract more attention and cause greater destruction than formerly. When the data already collected in regard to the Charleston earthquake shall have been tabulated, it will doubtless be found that the displacements which occasioned the vibrations were located along a line parallel with the Alleghanies and at a depth of from ten to twenty thousand feet, not under but westward of the city.

The Ornithorhyncus.—Dr. Pfuhl, in his lecture on "Animal-Plants and Plant-Animals," published in our last number, spoke of the ornithorhyncus as being a true mammal, and bringing forth its young alive. Such was believed to be the case till very recently. Mr. W. H. Caldwell, who has resided for some two or three years in Australia engaged in special investigations of the mysteries connected with the mammals of that country, has recorded the discovery that the monotremata, or animals of the order of which the ornithorhyncus is a member, are oviparous, and lay eggs, the development of which bears a close resemblance to the development of the eggs of the reptilia. He has read several papers relative to his investigations before the scientific societies of New South Wales, in one of which, before the Linnæan Society, he exhibited specimens that he had obtained in Queensland, showing the stages in the development of the animals from the laying of the eggs to the hatching.

Some Inherited Phenomena of Alcoholism.—Dr. T. D. Crothers, of Walnut Lodge, Hartford, Connecticut, has made a study of a class of phenomena which have not been previously described specifically, in which a liability to exhibit the outward signs of intoxication upon excitement appears to have been inherited from inebriate parents. He has found two classes of the cases: one, in which the symptoms of intoxication are present all the time; the others in which those symptoms only appear from some peculiar circumstances or exciting causes. In the first class, some prominent defect, such as idiocy, imbecility, or congenital deformity, is present to give the case a distinctness irrespective of the signs of intoxication. The symptoms may appear after birth, or be slowly evolved with the growth of the child, and come into prominence at or before puberty. Of course, all the varied phases of idiocy, imbecility, progressive degeneration, and malformation go on. The presence of a special class of symptoms resembling intoxication so clearly, suggests a distinct alcoholic causation. In the second class of cases noted, the alcoholic symptoms are not present, unless from some exciting cause (non-alcoholic), such as anger, fear, or sudden excitement. In this class are idiots, imbeciles, and defectives of all degrees, who at times display distinct signs of intoxication, that subside after a period. Often in these cases appear the common delusions and deliriums of intoxication; also, the semi-paralysis and stupor. Teachers and superintendents of asylums and schools for this class realize clearly the danger of excitement on these dements and defectives, throwing them into various states of mania, as well as intoxication. Several remarkable incidents illustrative of these