Hidrológiai Közlöny 1950 (30. évfolyam)

5-6. szám - Kivonatok

The ilme requirements of Gammarus pulex DE GEER«. Mechanica of the piping phenomenori. Z. Szabó, jun. (Hungárián text on p. 203.) U. D. C. 595.3 The Gammarus"pulex De Geer is not only a »fishfoodanimal« (Schaperclaus), but it is alsó »biological indicator« (Naumann, Szabó, Wundsch). According to the up-tD-date literature its occurence is bound to a relatively high chalkcontents (CaO) (Brehm, Haempel, Hesse, Mika-Varga, Schaperclaus, Schumann,Smolian, Wesenberg-Lund, Wundsch) The author of this study ascertained by researches on the spot (cf. the table ; in the brooks of the eruptive mountains Avas and Hargita, Transylvania), that Gammarus occurs alsó in very soft waters, moreover it is breeding there. Consequently it is not sensitive for the absence of chalk. By this observation the author justified the opinion of Thienemann contrary to the experiences and the theory of Wundsch and the theory of Schumann. Gammarus pulex De Geer is well breeding alsó at a hardness of 0-17

: Calcium, or 1-24 mg/1 solved Calciuinions in brooks. Lowland Trout-breeding. By György Lányi D. sc. (Hungárián text on p, 209.) U. D. C. 639.3 13:639.211.3 Fish-breeders inostly oppose trout-breeding in lowlands on basis of misconceptions of the living conditions of the trout, and trout-breeding on the territory of the Popular Republic of Hungary is not considered a commercial proposition. This misconception is apt to deprive the country of the prospects of a paying line of pisciculture. The author carried out research into this problem at the trout-ponds of Garadna, near Lilla-füred, in the Bükk Mountains, the results of which make him feel authorized to refute the above misconceptions. The author has found that the trout feeds well at temperatures above 20° C if the water has a sufficient oxygen content and does not suffer from shortage of oxygen as long as the water contains 4—5 cu. cm per üt. The author has carried out experiments of change of surroundlngs and produced at the Garadna trout-ponds living conditions similar to the semi-eutrophic carp-ponds of the Great Hungárián Plain. Under such conditions trout groth was much above that found in the originál trut-ponds with quick streaming water. There are many creeks in the promontories and hilly regions of Hungary where troutbreeding would be successful and trout-ponds might alsó be established in lower regions where water conditions are favorable. The author carried out feeding experiments in the Garadna Valley and found that this most important cost item of trout-breeding could be substantially reduced. In the 30-ties trout price was monopolistic in Hungary and workers could not afford it. With more economie feeding and good organization and extension of breeding this price can be lowered to a limit which would allow modest households to consume this excellent and nourishing fish. Considering natural and aconomic viewpoints the author advises lowland fish-breeders to extend their operations to troutculture as well. E. Doniján. (Hungárián text on p. 217.) U. D. C. 626.01 : 627.4 In the constructions of levees or dikes, on the proteeted sidc, crateriform outbursts of water are often observed, in which soi, particles are boiling and are building up a circular dani round the crater. This phenomenon is called »piping«. Piping occurs when the pressure of water exceeds the immersed weight of the soil particles. (Fig. 1. & 2.) Particles of the least dense part of the soil are loosened, kept in suspension, and an axial syinmetrical drain effect is produced around this place of high permeability, this is the cause of circular form of out brust. As long as the velocity of the water flow does not exceed the settling velocity of the soil particles, the material in suspension remains inside of the crater, but with increasing velocity the system becomes unstable, and the finest particles are scoured out of it. (Fig. 3.) If for somé reason the velocity of flow does not exceed the above limit, conditions may remain stationary. Summary Balneotherapy and eye diseases. S. de Grósz M. D. (Hungárián text on p. 222.) U. D. C. 615.838:617.7 The role ot baths and drinking cures in treating ocular pathology is disoussed. This form of therapy is totally neglected nowadays. Following indications are presented : salinebaths for phlyctenular processes and endocrine uveitis. Sulphuric baths in iritis due to chronic syphilis. and recurrent rheumatic episcleritis ; radioactive baths in senile and arteriosclerotic changes. Drinking mineralwaters should be administered for following purposes : waters containing calcium against allergic diseases, sulphate for chronic uveitis in women, iodine in all diseases requiring absorptive treatment. Ferrous waters in anémia, sulphuric cures in rheumatic conditions, radioactive waters in circulatory diseases of fundus etc. Local teratmcnt is of small value. The possibility of wide application and changing of neurohormonal balance is einphasized. The systemic attack on eye diseases may be brought about by critical use of balneotherapeutic measures. Benierkung zu Band. XXVI. Jahr 1946. der Hydrologischen . Mitteilungen. dr. Franz Pávai-Vajna. (Ungarincher text p. 230.) U. D. C. 551.49 (049.2) Der Aufsatz behandelt die Herkunft und Verwendung unserer Tiefengew&sser. Die Kenntnis dieser Tiefengewasser ist höchst bedeutungsvoll, da wir damit die Probleme der Heilquellenversorgung leichter zu lösen im Standé sind. Ausserdem stellt es auch wertvolle Gedanken auf in Hinsicht auf unsere Fragen der Wasserwirschtaft, dessen einige für den wasserwirtschaftlichen Teil unseres 5 Jahres-Planes ausserordentlich wichtig sind. HIDROLÓGIAI KÖZLÖNY Felelő; szerkesztő: Venkovits István. — Felelős kiadó: Tudományos Folyóiratkiadó Nemzeti Vállalat Vezérigazgatója Budapest nyomda NV V., Qerlőciy-utca 2 — 3950 — Felelős vezető Ifj. Puskás Ferenc