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Page:Popular Science Monthly Volume 32.djvu/97

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very general and the prices are regulated by free competition, the watering of oysters by floating in the shell is, perhaps, less reprehensible than at first thought it might seem. This phase of the question, however, it is not the purpose of this article to discuss.

5. From the standpoint of chemical physiology the most interesting outcome of the experiments is the very interesting parallelism they show between the processes by which the salts and other materials pass from within the body to the surrounding medium and those by which the digested materials of the food in man and other animals are conveyed through the walls of the alimentary canal into the blood and lymph to serve their purposes in nutrition. In each case the process seems to be due in part to osmose (dialysis) and in part to a special function of the organs.

To recapitulate still more briefly: The oysters in "floating" in fresher water, for some hours after they were taken from the beds in salt water, as is commonly done in preparing them for the market, gained from one eighth to one fifth in bulk and weight by taking up water, but at the same time lost about one tenth of their nutritive material. They did this by processes essentially similar to those which go on in our own bodies, and by which the digested food passes from the alimentary canal into the blood, to be used for nourishment.



GEOGRAPHY has been the last of the sciences which are studied in school to be affected by the modern demand that science shall be taught according to the scientific method. It is extremely important that this method of teaching the description of the earth should speedily become general, for most pupils study geography, and those who leave school at an early age may not otherwise obtain that quickening of the powers of observation and inference which the study of science gives.

Furthermore, to quote Professor Geikie, "Geography, in the wide and true sense of the word, offers admirable scope for this kind of training. It may be begun on the very threshold of school-life, and may be pursued in ever-increasing fullness of detail and breadth of view up to the end of that time. No other subject can for a moment be compared with it in this respect. It serves as common ground on which the claims of literature, history, and science may be reconciled." In order to aid teachers in leading their pupils into the study of

  1. "The Teaching of Geography. Suggestions regarding Principles and Methods for the Use of Teachers." By Archibald Geikie, LL.D., F.R.S. London and New York: Macmillan & Co. Pp. 202. Price, 60 cents.