Page:Popular Science Monthly Volume 36.djvu/298

286 by the deterioration of his higher faculties, of reversion toward the lower forms from which man is derived. Thus, the dying human subject sinks functionally lower and lower in the scale of animal life. In sleep it will be seen, if we consider the nervous system, that the parts peculiar to man, or most developed in man, are the ones that for the time being are as good as annihilated. Similar tendencies toward a sinking to equality with lower forms may be observed in hypnotism, somnambulism, and allied phenomena. It is seen, on a lower level, in hibernation, when certain normally very active animals return to a condition like that present in cold-blooded animals. In paralysis, the graver the affliction the lower in the scale must we seek to find an animal comparable to man in that condition. Views in harmony with those of Prof. Mills were published by Dr. Milner Fothergill.

The Office of Iron in the Blood.—Iron exists in the blood in the red corpuscles, and gives them color and the power of absorbing gases. The fact that peroxide of iron is one of the readiest absorbents of gases, and parts with them as readily on exposure in thin layers to the air, so that it can be used over and over again for that work, gives a clew to its special function in the red corpuscles of the blood. It enables them readily to absorb oxygen as they pass along the minute blood-vessels of the lungs, and to carry it to all parts of the body, where they part with it as it is demanded. It is supposed, also, to take up carbonic acid in exchange for the oxygen it yields up, and to convey to the lungs that portion of this substance which is expired. If this be its double function, it is one the importance of which can hardly be exaggerated; for it is, in effect, to be the vehicle to all parts of the organism of that which makes them vital, while it also removes the waste of their life, which would otherwise clog their activity. The chemical changes in the life of plants are effected by means of the iron which is contained in the chlorophyl by processes that differ in particulars, but are dependent on the same absorption principle of the peroxide. Thus "it is an interesting coincidence that iron should be the active agent in both animal and vegetable life for the assimilation of the air substances required for their existence; and that at the same time it should be intimately connected with the production of the distinctive color of the blood and of the foliage of plants."

Iron Railway-Ties.—Iron sleepers or cross-ties have been in use for many years on the railroads of India, and have proved as free from liability to accident as wooden ties. The East India Railroad has more than one thousand miles laid with them, and is adding to the length every year. It runs the fastest and heaviest trains on the peninsula, and has enjoyed an almost proverbial immunity from accidents. The "bowl sleeper" appears to be the standard type, although it was once condemned. It lies more steadily and is less liable to horizontal displacement than any wooden sleeper. It, however, makes the track too rigid, and is not suitable for high speed, and is likely to be discontinued again. A tie called the "D and O sleeper" gives a more elastic track, and is more conveniently packed than the hollow sleepers.



Board of Directors of the Zoölogical Society of Philadelphia asserts in its last report that the collection has at no previous time been so well able to fill its part among the educational institutions of the city as at present. It contains a sufficient variety of specimens to give a comprehensive idea of the four classes of vertebrates. Some of the larger groups are exceptionally well represented. The series of monkeys is large, and contains a number of species rarely seen in captivity, as well as six specimens of lemurs. The collection of parrots is also worthy of special attention. Arrangements have been made for securing an extensive collection of North American forms of reptiles and amphibians.

of "The Sociological Position of Protection and Free Trade" leads Mr. Lester F. Ward to the conclusion that "free trade, laissez-faire, and individualism in general, represent the untamed forces of nature, such as would exist in the physical world had there never been any inventions, contrivances, machinery, or arts"; while "protection belongs to the great class of ingenious instrumentalities which the civilized brain of man has learned to devise and employ for the regulation, control, and utilization of natural agencies."