Page:Popular Science Monthly Volume 42.djvu/149

Rh began to cut its way year after year, century after century, millennium after millennium. As the waters of Lake Ontario began to subside, the height of the Falls increased. The upper stratum of rock is Niagara limestone, a hard rock, but beneath it is a stratum of Niagara shale. It is the slow undermining of this shale that causes the Niagara limestone rock to break off from year to year and the Falls to recede. How long it has taken the Falls to go back from Lewiston I do not know. They are going now at the rate of three or four feet a year. At that rate some ten or twelve thousand years would have done the work. The lowest estimates are from seven to eight thousand years. I for my part am inclined to favor the higher estimate. Well, they are still going backward. What will be the final result? They may go back to the lake; but the Niagara limestone is growing thicker and thicker, and may finally extend to the bottom of the fall. In that case the rock would not break off, but would wear away and form a rapids. In any case, if the Falls should recede to Lake Erie, at the present rate it would take at least twenty thousand years, and, of course, we can not be very strongly personally interested."

Cause of Seasickness and Remedies for it.—The inducing cause of seasickness, according to the studies of Dr. Herbert Damvers, is a mechanical irritation of the walls of the stomach due to contact of parts not usually in apposition with one another. The effect of this is to produce reflex stimulation of the vomiting center in the medulla and directly a subacute gastritis; diminished blood-supply to the head and neck (as seen in the extraordinary pallor of the face); and a disturbance of cerebral circulation, resulting in a general nerve starvation, which is evidenced by headache of neuralgic intensity. The author would for clinical purposes group all cases into three divisions, according as head symptoms or gastric symptoms largely predominate, or head and gastric symptoms are combined in nearly equal degrees (mixed cases). The author treats cases of the first group with enemas, followed by nerve sedatives, and then with measures to raise depressed spirits. In cases of the second group he administers warm water as an emetic, followed by prescriptions for allaying gastric irritability. For the mixed cases soda and compound tincture of cardamoms or nitromuriatic acid during the day, with a pill of calomel, colocynth, and hyoscyamus at bedtime, have been found efficient. These methods of treatment apply solely to large ocean steamers, on which the passengers remain a week or more. In the case of short trips on small vessels, in which the motions are different, the author is sure that we have no drug or combination of drugs that will act as a panacea.

Biological Teaching in American Colleges.—Reviewing the present condition of biological teaching in the colleges of the United States, Prof. John A. Campbell remarks that we have now advanced to a stage where we can no longer expect much biological research to be done by private persons, and must look largely to the colleges for work of a purely scientific character. Many problems are peculiar to the country, arising out of the character of its flora and fauna; while, on the other hand, certain kinds of work find in this country more favorable conditions than prevail elsewhere. Much is still to be done in purely descriptive work. There are many regions to be explored before we will know the entire flora and fauna of the United States, and our knowledge of the life histories, especially of the lower vegetable forms, is in a peculiarly unsatisfactory condition. Co-operation among investigators is especially necessary if the best results to the individual are to be reached; while specialization of research is equally imperative for the best interests of science. At present, in this country, these two points are not equally guarded, for we do not find sufficient efforts made to resist the narrowing tendency of specialization. Prof. C. O. Whitman has pointed out the necessity for organization among investigators, and as a result of his efforts there is a much more wide-spread appreciation of this necessity than ever before. There have been advanced lecture courses and courses and co-operative studies in current literature at Johns Hopkins University ever since its foundation. In but few other institutions do the catalogues contain any accounts of such work. But the present indications are hopeful. The necessity for the work is coming