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THE POPULAR SCIENCE MONTHLY. 



by the deterioration of his higher faculties, 

 of reversion toward the lower forms from 

 which man is derived. Thus, the dying hu- 

 man 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 equal- 

 ity with lower forms may be observed in 

 hypnotism, somnambulism, andallied phenom- 

 ena. It is seen, on a lower level, in hiberna- 

 tion, when certain normally very active ani- 

 mals return to a condition like that present 

 in cold-biooded 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 ab- 

 sorb 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 re- 

 moves 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 partic- 

 ulars, but are dependent on the same absorp- 

 tion principle of the peroxide. Thus " it is 

 an interesting coincidence that iron should 

 be the active agent in both animal and vege- 

 table life for the assimilation of the air sub- 



stances required for their existence; and 

 that at the same time it should be intimate- 

 ly connected with the production of the dis- 

 tinctive 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 Kailroad 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 pen- 

 insula, and has enjoyed an almost proverb- 

 ial 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 

 sleeper" gives a more elastic track, and is 

 more conveniently packed than the hollow 

 sleepers. 



NOTES. 



The Board of Directors of the Zoological 

 Society of Philadelphia asserts in its last 

 report that the collection has at no previ- 

 ous 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 le- 

 murs. The collection of parrots is also wor- 

 thy of special attention. Arrangements have 

 been made for securing an extensive collec- 

 tion of North American forms of reptiles 

 and amphibians. 



A review 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, contriv- 

 ances, machinery, or arts " ; while " protec- 

 tion 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 nat- 

 ural agencies." 



