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764 Agassiz to be in a better state of preservation, and their localities more accurately noted, than is the case with any similar collection he has seen. To give an idea of the magnitude of the Challenger collections, he says that if a single individual, possessing the knowledge of the eighteen or twenty specialists in whose hands they are to be placed, were to work them up, he would require from seventy to seventy-five years of hard work to bring out the results which the careful study of the different departments ought to yield. At the same time Prof. Agassiz observes that little that is new has been added by the Challenger Expedition to the deep-sea fauna as developed by the American and English Expeditions of 1866 and 1869. Reasoning from these premises, "we may safely say that while any new expeditions will undoubtedly clear up many of the points left doubtful by the Challenger, and may carry out special lines of investigation only partly sketched out, yet we can hardly expect them to do more than fill out the grand outlines laid down by the great English Expedition."

Preservation of Ice in the Sick-Room.—Dr. Gamgee, in the Lancet, suggests a good method of preserving ice in small quantity for a considerable time at the bedside of a sick person. His practice is to cut a piece of flannel about nine inches square, and secure it by ligature round the mouth of an ordinary tumbler, so as to leave a cup-shaped depression of flannel within the tumbler to about half its depth. In the flannel cup so constructed pieces of ice may be preserved many hours, all the longer if a piece of flannel from four to five inches square be used as a loose cover to the ice-cups. Cheap flannel, with comparatively open meshes, is preferable, as the water easily drains through it, and the ice is thus kept quite dry. When good flannel with close texture is employed, a small hole must be made in the bottom of the flannel cup, otherwise it holds the water, and facilitates the melting of the ice. In a room with a temperature of 60° Fahr., Dr. Gamgee made the following experiments with four tumblers, placing in each two ounces of ice broken into small pieces. In tumbler No. 1 the ice was loose. It had all melted in two hours and fifty-five minutes. In tumbler No. 2 the ice was suspended in the tumbler in a cup made, as above described, of good Welsh flannel. In five hours and a quarter the flannel cup was more than half filled with water, with some pieces of ice floating in it; in another hour and a quarter the flannel cup was nearly filled with water, and no ice remained. In tumbler No. 3 the ice was suspended in a flannel cup made in the same manner and of the same material as in No. 2; but in No. 3 a hole capable of admitting a quill pen had been made in the bottom of the flannel cup, with the effect of protracting the total liquefaction of the ice to a period of eight hours and three-quarters. In tumbler No. 4 the ice was placed in a flannel cup made, as above described, of cheap, open flannel, which allowed the water to drain through very readily. Ten hours and ten minutes elapsed before all this ice had melted.

Grote's Theory of the Peopling of America.—Prof. Grote's theory of the original peopling of America, as stated in recent papers, is that the original inhabitants came from Asia by way of the north during the latter part of the Miocene or earlier part of the Pliocene, and that this Tertiary population spread to the south along the mountainous backbone of the two Americas; that, on the advent of the Glacial epoch, the people then living in the extreme north were modified by the change in climate and were brought down by the ice and followed it back again to the arctic circle, and that the present representatives of glacial man are the Esquimaux. Through a study of migrations Prof. Grote comes to the conclusion that the ice must have acted as a barrier to further communication between the two continents of Asia and North America, and consequently that the civilizations of Central America and of the mound-builders are indigenous. Grote concludes that the theory of an accidental migration from Asia during the Quaternary cannot be supported in view of recently-ascertained facts. In a letter dated February 11, 1877, Captain E. L. Berthoud (of the School of Mines at Golden, Colorado), who has studied the geology and archæology of the West since 1859, writes that Grote's theory "solves many knotty points in the antiquities and