Bulletin of the Minnesota Academy of Natural Sciences, Volumen3

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Página 52 - But this evidence of previous contamination implies much more risk when it occurs in water from rivers and shallow wells, than when it is met with in the water of deep wells or of deep-seated springs. In the case of river water, there is great probability that the morbific matter sometimes present in animal excreta will be carried rapidly down the stream, escape decomposition, and produce disease in those persons who drink the water, as the organic matter of sewage undergoes decomposition very slowly...
Página 59 - Leaf hills, respectively about 2000 and 1700 feet above the sea, to half that hight, or from 1000 to 800 feet, in the long flat basin of the Red river valley, and to the same hight along the valley of the Mississippi from Saint Cloud to Minneapolis. The only exceptions to this moderately undulating or rolling and rarely hilly contour, are the southeast part of the state where the Mississippi river and its tributaries are enclosed by bluffs from 200 to 600 feet high, and the northwest shore of lake...
Página 35 - Gnats dance before the eyes, and often fall in unless you shut them; insects creep on you and into your ears. Ants crawl on you whenever you rest on the ground; wasps will assail you like furies if you touch their nests. But ticks, the worst of all, are unavoidable whenever you go among bushes, and stick to you in crowds, rilling your skin with pimples and sores. Spiders, gallineps, horseflies and other obnoxious insects will often beset you, or sorely hurt you.
Página 35 - Rafinesque's botanical writings from 1819 till 1830, when the passion for establishing new genera and species seems to have become a monomania with him. He assumed thirty to one hundred years as the average time required for the production of a new species, and five hundred to a thousand years for a new genus. It is said that he wrote a paper describing " twelve new species of thunder and lightning.
Página 251 - ... of bedding and joint cracks; or occur as segregations in the rock ; or form the cement of a brecciated novaculite, in which the masses of rock vary from a fraction of an inch to several feet in diameter, and are surrounded on all sides by layers of manganese ore from a fraction of an inch to several inches in thickness.
Página 71 - ... stumps were seen ten feet or more in diameter, and I heard of others still larger. This region will yet prove a mine of wealth to the botanist studying our fossil flora. Fossil leaves in great abundance occur everywhere in the Tertiary sandstones and soft Cretaceous clays. In some places the clay beds were originally underlain by seams of lignite, which have been burned, baking the clay above into a kind of brown, red, or yellow brick, which shows perfectly the forms and venation of these fossil...
Página 67 - ... seen. Two species ofLinum, L. rigidum, Pursh, and L. perenne, L., were found. The latter grows very rank, with showy blue flowers, often more than an inch in diameter. The seed-vessels were observed later in the season, and were found to be nearly as large as in the cultivated flax (L. usitatissimum, L.), with seeds about half as large, of a shining dark brown color, and apparently containing a considerable proportion of oil. The question arises, -whether this wild flax could be improved by cultivation...
Página 68 - The separation in these species is effected by means of a constriction on the sfcm, which cuts off. as it were, the nourishment from the root, and causes the stalk to shrivel at that point, when the least touch or gust of wind releases the plant. On the hills near Mandan, and in no other place along the route, Petalostemon macrostachyus, Torr., was collected. Here also P. villosus...
Página 287 - ... Oldest of our state parks, its place at the source of the greatest river of North America gives to it national significance and value, geographic, historic, and educational. The first expedition seeking to reach the head of the Mississippi was that of General Lewis Cass in 1820, penetrating the northern forest to Cass lake, which seems to have been regarded for some years afterward as the principal source of the river. A few years later, in 1823, Beltrami traversed the country between the Red...
Página 52 - When the sewage of towns or other polluting organic matter is discharged into running water, the suspended matters may be more or less perfectly removed by subsidence and filtration, but the foul organic matters in solution are very persistent.

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