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See detailObservations sur l'action détersive des solutions de savon : Troisième communication : Les solutions de savon et l'hydrosol aluminique
Spring, Walthère ULg

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1909), (11), 1059-1065

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See detailObservations sur l'action détersive des solutions de savon : Deuxième communication : Les solutions de savon et les composés ferriques
Spring, Walthère ULg

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1909), (9-10), 949-966

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1909), 949-66; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Blood ... [more ▼]

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1909), 949-66; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Blood and colloidal hydrate of iron easily form with soap a combination of adsorption which is not sol. in H2O. This combination in presence of H2O does not have the power of adhering to glass, porcelain, cellulose, skin, etc. Hence such substances are cleaned by soap because the colloidal combination is not adsorbed by these solid substances. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

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See detailObservations sur l'action détersive des solutions de savon : Quatrième et dernière communication : Les solutions de savon et l'acide silicique, l'argile et la cellulose
Spring, Walthère ULg

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1909), (12), 1128-1139

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See detailObservations sur l'action détersive des solutions de savon : Première communication
Spring, Walthère ULg

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1909), (1), 187-206

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1909), 187-206; 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 (1909), 187-206; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Lampblack purified from fats and resins was tested for its rate of sedimentation in pure H2O, in 0.01-2% soap solns., in 0.01-2% soap solns. containing an equivalent of HCl or of KOH, and in MeOH or EtOH solns. of soap, the concentrations of soap being 1/50 and 1/60% in the MeOH and 0.02% in the EtOH. In H2O and in 2% soap soln. lampblack remained in suspension to the same extent; in 0.5% soap soln. in 6 days a small amount of lampblack remained in suspension; in I% soap soln. lampblack remained in suspension for more than 2 mos. In all cases some of the lampblack was deposited. The acid solns. in the different concentrations cleared quickly, while the alkaline solns. held the lampblack in suspension better than H2O. The alcohols acted as H2O, but to produce an effect of the same order, their mass ought to be 50-200 times as great as that of H2O. The soap soln. shaken with lampblack gave a heavier ash than the soap soln. alone. The soln. seemed to be divided into 2 parts, a more acid one which agglutinated with the lampblack and a more basic one which remained in the soln. Proof of this was found from the smaller ash remaining from the residue after treating in alc. The alc. solns. gave less of a detergent effect. The sediment of lampblack in the soap soln. differed from that in H2O by being viscous and oily while that in H2O was grainy and easily thrown into suspension in H2O. On filtration the lampblack from H2O suspensions blackened the paper completely while from soap soln. the particles not in contact with the paper were readily detached. Lampblack in pure H2O with a current of 8 volts did not conduct; in H2O rendered slightly alkaline the lampblack was deposited at the cathode; in a 2% soap soln. after some hrs. lampblack was deposited at the anode. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

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See detailObservations sur l'action détersive des solutions de savon : Première communication
Spring, Walthère ULg

in Recueil des Travaux Chimiques des Pays-Bas et de la Belgique (1909), XXVIII

Spring, W. Recueil des Travaux Chimiques des Pays-Bas et de la Belgique (1909), 28, 120-35; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). The ... [more ▼]

Spring, W. Recueil des Travaux Chimiques des Pays-Bas et de la Belgique (1909), 28, 120-35; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). The action of soap is explained by the following facts: (1) Carbon hastens the decomp. of soap in water by causing the formation of an acid salt. This combination of C with the soap is not stoichiometric but a combination such as exists between colloidal substances. The combination of the C with the soap is formed because of the difference of the electrical polarity of its constituents from water. (2) C suspended in water forms a combination of absorption more or less stable with the solid substances, especially cellulose. This, the author says, is proved by the fact that a suspension of finely divided C in water will give up its C to filter paper when filtered, and if the paper is then inverted the C cannot be washed off by means of water. There exists a combination of colloidal C and paper. (3) A suspension of C in soap solution is characterized by its stability. When filtered all of the C passes through the filter paper. In his experiments the author employed a 2% soap solution and C from which all oily matter had been removed so that there was no chance for emulsions. It was found that there was an optimum % of concentration for which the C remained in suspension. In a 2% sol. the C deposited almost as rapidly as in pure water, but in solutions of less than 0.5% the deposition was slower. In a 1% sol. the C remained in suspension about 2 months. All of the soap solutions which had retained C in suspension nevertheless had a sediment. Acid and alkaline solutions of soap were tried with regard to their power of holding C in suspension. The acid solutions became clear rapidly while the alkaline held the C better than pure water does. MeOH and EtOH solutions of soap were also tried. The deposition of C from these took place more rapidly than in the case of water. Soap solutions which deposited C were examined to see whether any soap was dragged down with the C. It was found each time that the % of ash of the sol. which had been agitated with C and then filtered, was greater than the corresponding % of ash of the sol. not so treated, which was run as a comparison. The author concludes that the soap sol. was slightly decomposed by contact with the C into an acid portion which agglutinated with C and into a basic portion which remained in solution. The MeOH and EtOH sols. of soap when examined in the same manner as above showed less ash. This would mean that the solution underwent no change and that there was no agglutination with the C. This also explains why alc. solutions of soap give inferior detersive effects. The sediment of C deposited from soap solution is different in character from that deposited from pure water. It is oleaginous and viscous. A suspension of C in water was subjected to electrolysis. With a difference of potential of 8 volts cataphoresis is doubtful, but when the sol. is made slightly alkaline the C acts as if charged electropositive and is deposited around the cathode. A 0.2% soap solution when electrolyzed gave a white deposit around the anode after several hours. This, when separated from the solution and the ash determined and compared with that of the filtrate, indicates that the deposit at the anode is an acid soap while the soap left in the solution is basic. The author is carrying on experiments to show the action of silicic acid, iron oxide, Al2O3, etc., in soap solutions. Also in Arch. sci. phys. nat. g.acte.en., 27, 229. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

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See detailEinige Beobachtungen über die Waschwirkung der Seifen
Spring, Walthère ULg

in Zeitschrift für Chemie und Industrie der Kolloide (1909), 4

Spring, W. Zeitschrift fuer Chemie und Industrie der Kolloide (1909), 4, 161-8; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Objections to ... [more ▼]

Spring, W. Zeitschrift fuer Chemie und Industrie der Kolloide (1909), 4, 161-8; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). Objections to Chevreuil's, Hillger's, Falk's, and Knapp's theories for the cleansing action of soap are presented. Experiments on the action of soap sols. on carefully purified lampblack bring out the following facts: Lampblack (charged +) hastens the formation of an acid salt (charged -) then forms an adsorption compound with it. A suspension of lampblack in soap sol. will run through filter paper while lampblack can be filtered from water sol. because of an adsorption compound between it and the filter paper. A 1% soap sol. gives an optimum suspension of lampblack, while a 2% is about equivalent to water. Small amounts of alkali increase the suspending power of a sol. greatly. 0.2-0.16% sols. of soap in MeOH, and 0.05% sol. in EtOH show the same optimum suspension for lampblack. The residue of soap obtained by evaporating a given vol. of sol. is the same, whether C has settled through it or not, but the ash in that residue is greater when C has been present, i. e., the basic part is higher in ash than the acid part. From MeOH the ash is less and the C has combined with the basic soap. From EtOH there is practically no difference. The C settled from soap sol. is a thick sirup, and cannot be purified, but forms a colloidal sol. in H2O. C in H2O is uncharged, but in alkaline sol. is + charged. From a 2% soap sol. a white ppt. of C + acid soap collects about the anode, and is lower in ash than soap obtained from the sol. by evaporation. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

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See detailNotre nom national
Kurth, Godefroid ULg

in Bulletin de la Commission Royale d'Histoire (1909), LXXVIII

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See detailRapport sur le mémoire présenté au concours de 1909 : Sur les invasions en Belgique, etc.
Kurth, Godefroid ULg

in Bulletin de la Classe des Lettres et des Sciences Morales et Politiques (1909)

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See detailObservations sur l'action détersive des solutions de savon : Deuxième communication : Les solutions de savon et les composés ferriques
Spring, Walthère ULg

in Recueil des Travaux Chimiques des Pays-Bas et de la Belgique (1909), XXVIII

Spring, W. Recueil des Travaux Chimiques des Pays-Bas et de la Belgique (1910), 28, 424-43; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). see C ... [more ▼]

Spring, W. Recueil des Travaux Chimiques des Pays-Bas et de la Belgique (1910), 28, 424-43; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). see C. A., 3, 1599-1613; 4, 138. In this investigation finely divided hematite (Fe2O3) containing 4.6% H2O) was treated in a manner similar to the C described) in preceding communication. It was found that in pure H2O it remains in suspension for days, but in acid or alkaline solns. it settles in 0.5 hr. When subjected to action of electric current the tendency is to migrate toward the cathode; hence particles must be positively charged. When Fe2O2 is shaken with soap solns. of varying strength all except those with about 0.5% soap settle in 5 days or less. Those with 7-8% show a ferric color in the clear soln. The residue on evapn. of the clear 7% soln. shows 17.66% and 17.50% ash, after deducting 1.13% Fe2O3; from the same soln. not shaken with Fe2O3 18.31%. Dilute KOH solns. (less than 0.1%) do not cause settling, but as little as 0.0001% HCl does so. A soln. of soap in MeOH was shaken with Fe2O3. The residue on evapn. of the clear soln. showed 17.68% ash; from the original soln. 18.24%. This shows a decomp. of the soap into a basic and an acid portion, the latter combining with the Fe2O3. Suspension of Fe2O3 in H2O filters clear after 16 filtrations, through same paper in alc., after 4. This is due to adsorption, and not to blocking of the pores, for if H2O be poured on the paper through which alc. suspension filtered clear, it comes through more and more turbid as the alc. is washed out. If 2% soap soln. be used instead, it looks as if filter had been pierced. This indicates that Fe2O3 forms an adsorption-combination with soap more stable than with cellulose or other materials. When colloidal Fe(OH)3 solns. are shaken with soap solns. clarification is found to depend on the relative amts. of Fe(OH)3 and soap. It is most rapid when the proportion is between 2.16 and 3.47 mols. Fe2O3 to 1 of soap. By a titration method the ratio was found to be 3.10-3.25:1 when Fe(OH)3 was run into the soap; 1 when soap was run into Fe(OH)3. The ppts. in the 2 cases were almost the same in comp., and were entirely different from the Fe soap prepared by adding FeCl3 soln. to soap soln., in which the ratio is 3 mols. soap to 1 mol. Fecl3. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

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See detailLes êtres dangereux par état
Thiry, Fernand ULg

Speech (1909)

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See detailFormation d’anticorps dans le sang du lapin par injection intraveineuse de sang de ver à soie
Fredericq, Léon ULg

in Archives Internationales de Physiologie (1909), VIII

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See detailSur l’emploi du citrate de soude comme agent anti-coagulant
Fredericq, Léon ULg

in Archivi di fisologia (1909)

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See detailGiftslangen
Fredericq, Léon ULg

in Vlaamse Gids (De) (1909), V

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See detailDe Afstamming van Vlamingen en Walen
Fredericq, Léon ULg

in Vlaamse Gids (De) (1909), II

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See detailDe la coordination organique par action chimique
Fredericq, Léon ULg

in Scientia (1909), V(1), 275-289

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See detailL’îlot glaciaire de la Baraque Michel
Fredericq, Léon ULg

in Ciel et Terre (1909), XXX

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