Page:Popular Science Monthly Volume 41.djvu/589

Rh and shad are practically kept from extermination by the efforts of fish commissions. One reason for this growing depletion of animals is found in the fallacy that, because some animals exist in large numbers, the supply is unlimited and the species needs no protection, which is indulged in till the species is on the verge of extermination. Usually, too, those most directly interested in the preservation of game are the bitterest opponents of protective measures, especially if the change will produce even temporary inconvenience. Although regret at the impending or actual extermination of a species is often purely a matter of sentiment, there is no lack of instances where the strictest utilitarian is quite as much interested as the naturalist in preserving a species from destruction. The pity of it is that in so many cases a small amount of protection would not only preserve for the naturalist the animals he wishes to study, but furnish the practical man with an additional source of wealth.

Concerning Overwork.—In treating the question whether laborious occupations in themselves may lead to premature strain of the body or mind, and so to degeneration or disease, Dr. P. H. Pye-Smith thinks we "must distinguish." Aneurism, emphysema, and some forms of cardiac hypertrophy may be the result of overstrained and too violent and prolonged exertion, from mechanical stretching of the great arteries by movements of the arms, from high blood-pressure, excessive calls on the heart, and over-long suspension of respiration, as in muscular efforts with a closed glottis. "We see similar results in horses which are put to too hard work at too early an age, and there is no reason to doubt the operation of such causes of disease in man. But their operation is limited to the production of certain definite lesions, and there is no evidence that harm is done, disease brought on, or life shortened by what is commonly known as work, whether mental, physical, or a combination of the two. The vanity of human nature is tickled by ascribing its disorders to such respectable antecedents as industry, energy, and intellectual activity. We must all have felt this when the results of habitual idleness or gluttony are ascribed by a patient or his wife to an overtaxed brain or too strenuous devotion to business especially in the public service. There is no fear of any one of us" (members of the Royal College of Physicians) "using our brains too much for our health, nor do I believe that mental labor or honest work of any kind interferes with health or shortens life a day. Even if it did, who would not rather be worn in use than rust in idleness? Who would not choose a short-spanned life, filled full of action and of thought, of sorrow and of joy, of effort and of endurance, of enjoyment of living one's self and helpful service to others, rather than to wear out a tedious existence of monotonous ease?"

Agriculture in Egypt.—The land of Egypt was irrigated in ancient times by turning the red water from the Nile at high flood into the basins into which the country was divided by the construction of earth-banks at convenient distances. The water was allowed to stand at a depth of three feet or more for forty or sixty days, till the earth had become saturated and the weeds had been killed, and the fertilizing layer of finely divided red mud had been deposited on the soil. The water being drawn off into the receding river, the seed was sown upon the soft mud. Sometimes the ground was left till it was dry enough to be plowed, and was then planted. In either case sufficient moisture for the supply of the crop was retained. This system of irrigation has been supplanted for the most part in Lower Egypt by the canal system introduced by Mehemet Ali, but is still in use in Upper Egypt. The difference in the power of the two systems to maintain the fertility of the soil may be estimated from the fact that a good crop of wheat grown under the basin system of Upper Egypt yields about twenty-seven bushels per acre; while, unless specially manured, the yield runs down under canal irrigation to about eighteen bushels and a half. In the latter instance, the greater number of crops taken, and the reduced amount of Nile mud deposited, make artificial manures necessary. A combination of the two systems gives the best results. A wonderful store of natural manure, called sabakh has for a number of years been drawn upon by cultivators in the shape of refuse earth from the mounds of ancient villages, and from the floors and