Sur l’innervation respiratoire chez le poulpe

in Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences (1879), LXXXVIII

Sur l'ordre de convergence de l'algorithme du point proximal perturbé

in Bulletin de la Société Royale des Sciences de Liège (1989), 58(6), 459-466

We suggest a condition to get, for the perturbed proximal point algorithm, a relation which gives an idea on the rate of convergence of the generated sequence.

Sur l'origine de la couleur bleue du ciel

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-arts de Belgique. Sciences. 3e série (1898), XXXVI(12), 504-518

Sur l'origine des nuances vertes des eaux de la nature et sur l'incompatibilité des composés calciques, ferriques et humiques en leur milieu

in Archives des Sciences Physiques et Naturelles (1905), 20

Sur l'origine des nuances vertes des eaux de la nature et sur l'incompatibilité des composés calciques, ferriques et humiques en leur milieu

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1905), (7), 300-309

Spring, W. Bull. de l'Acad. royale de Belg. (1905), 1905, 300 to 310; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). After Baron V. AUFSESS (Die ... [more ▼]

Spring, W. Bull. de l'Acad. royale de Belg. (1905), 1905, 300 to 310; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). After Baron V. AUFSESS (Die Farbe der Seen. Inaug.-Diss. Muenchen 1903) the refraction of the light does not have influence on the change of the blue color water, mainly also because one can obtain green water by dissolving lime compounds/connections, yellow or brown water by solve ones of humus substances in pure water. The going by experiments of the authors, which are down partly in detail described, led however to the subsequent results: the lime compounds/connections natural water do not have inherent color and are not a cause of the much-observed green coloring in with examination appearing even clear lime water; the green, after elimination of the dyes residual coloring contained in the water is the result of the refraction of the light through invisible portion cups, which the water still includes, and whose presence can be done by an intensive light beam. The lime compounds/connections affect strongly fell in the water contained the ferric compounds/connections and with these on the humus substances, which the latter natural color water strongly change. Lime salts protect therefore the blue color water. In case of the not-blue, lime-containing, natural water an equilibrium between the cleaning effect of their lime compounds/connections results and steady influxes of the humus and ferric compounds/connections, which let disappear its brown coloring lower for itself the blue color water. The blue, more or less greenish color of the purest water give information over the point, where the equilibrium between the antagonists is fixed. Purely blue water (6 m coating thickness) becomes green by dissolving lime from Icelandic double spar; when introducing CO2 a clear, somewhat less green solution of acid calcium carbonate forms; also gypsum colors such water green. During the passage of radiation of electrical light these solutions appear, particularly the CaH2(CO3)2-containing, optically clouds, it carefully to dry was evaporated, the residue contained partially organic substance, partially SiO2 or silicates (from the glass of the container), which were contained in the solution therefore in the colloidal condition. After filtering the other Ca-containing solutions by animal charcoal these showed the same blue color as pure water. When regarding by a pipe of 6 m length appears pure water with 1/1 000 000 part ferric hydroxide brown, with 1/2 000 000 green, with 1/5 000 000 unmodified blue. With humus substances the blue color is already changed by more than 1/40 000 000 part. Ferric salts color brownish; they are particularly reduced by humus substances, in the light, sometimes partially to ferrous compounds/connections, whose color is not possible, and which with the humus substances insoluble, failing compounds to be received. To a liter of clear solution with 1/3 000 000 if part colloidal Fe(OH) 3 (to dissolve of FeCl3 in H2O) is added a same volume acid calcium carbonate or CaSO4-Solution, then a flocculation, tags begins is because of the container soil a brown, ocher-colored dirt, the water is perfectly clear, appears green and leaves a residue of CaCO3 or CaSO4 without trace iron after few instants; the sediment contains 85-90% Fe(OH)3, CaCO3 or CaSO4. Also with insoluble CaCO3 begins the flocculation of the ferric compounds/connections immediately; similarly soluble salts work; with sodium chloride (sea water) a trace remains iron in solution. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

Sur l’origine hippocratique des concepts de révulsion et de dérivation

in Antiquité Classique : Revue Interuniversitaire d'Etudes Classiques (1980), 49

Sur l'unité d'origine du bleu de l'eau

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1899), (2), 72-80

Spring, W. Bull. Acad. roy. Belg. (1899), 72; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Tyndall's experiments have been repeated and it was ... [more ▼]

Spring, W. Bull. Acad. roy. Belg. (1899), 72; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Tyndall's experiments have been repeated and it was found that suspended particles do not give a blue color to the water. Further experiments showed that fluorescence was not a factor, and the final conclusion reached is that the blue color of water is due simply and solely to the fact that water is blue in color. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

Sur la capacité de saturation des combinaisons colloïdes

in Archives des Sciences Physiques et Naturelles (1911), XXX

Spring, W. Archives des Sciences Physiques et Naturelles (1911), 30, 561-71; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). cf. C. A., 4, 138, 969 ... [more ▼]

Spring, W. Archives des Sciences Physiques et Naturelles (1911), 30, 561-71; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). cf. C. A., 4, 138, 969, 1911. This is a report of some suggestive expts. on the mutual adsorption relations of saponin, lampblack and filter paper. When varying amts. of saponin are added to a standard suspension of lampblack in water the solns. of high and of low conc. settle faster than do the intermediate ones. There is an optimum stability at a conc. of saponin between 2.0 and 3.5%. In an elec. field saponin moves toward the anode, lampblack toward the cathode. When saponin is added to a lampblack suspension and an elec. current is passed the lampblack moves toward the anode-a reversal of the direction which it exhibits when alone. When a suspension of lampblack is poured through a filter the paper retains a part of the lampblack and this retained portion cannot be removed by washing with water, even when the filter is reversed. But if a soln. of saponin be poured through the blacked filter a portion of the retained lampblack is given up and passes through with the soln. A crayon made by molding a mixture of wet clay with lampblack or finely ground graphite marks paper easily and leaves a mark which is erased with difficulty. If, however, a soln. of saponin be used to moisten the clay-lampblack mixture the crayon is harder, marks paper with difficulty and the mark is easily erased. Similar results are obtained when the paper, instead of the crayon, is impregnated with saponin. When filter paper pulp is mixed with a lampblack suspension and collected on a cloth filter, the pulp retains some of the lampblack and the amt. so retained is sensibly independent of the conc. of lampblack in the original suspension. The author makes certain applications to the action of soapy substances in the cleansing of fabrics and concludes that there exists a limiting "saturation capacity in the combinations between colloids" which is analogous to the saturation of one atom by chem. combination with another. [This conclusion is quite out of accord with the existing knowledge of the form of the absorption isotherm and is not supported by the evidence presented. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

Sur la cause de l'absence de coloration de certaines eaux limpides naturelles

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-arts de Belgique. Sciences. 3e série (1898), XXXVI(9-10), 266-276

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1898), 38(3), 266-76 ; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010 ... [more ▼]

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1898), 38(3), 266-76 ; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Tying to its earlier reports over the role of the iron compounds and the humin substances with the feature of the coloring of water and over the elimination of this substances under influence of sunlight, etc. (Bulletin Acad. roy. Bolgique [3] 34. 578; C. 98. I. 410 and Rec. trav. chim. Pays-Bas 17. 202; C. 98. II. 224) author the cause of the colorlessness many discusses clear waters, about what already Berzelius (Annual Report f. Chemistry 9. 207) expressed its astonishment. Terrestrial water only very rarely will appear blue, since in all ground are traces of hematite, and this the blue color water for our eye compensates. On the other hand the glaciers and the snow of high peaks do not contain hematite, water from high regions throw their blue and therefore can maintain their color. Furthermore the influence of the iron compounds on the coloring water is very differenct, depending on whether they are in the form of their hydrates or anhydrous oxides in the water; into latter trap they step with the Humin or the organic substances water not into reaction, the water more generally continues to appear colorless. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

Sur la cause de l'apnée

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique. Sciences (1900)