Showing papers by "University of Jena published in 1973"

Conspectus der „Thlaspi”︁‐Arten Europas, Afrikas und Vorderasiens

Abstract: Als Ergebnis kritischer Untersuchungen an den Thlaspi-Arten Europas, Afrikas und Vorderasiens werden die bei der Gattung Thlaspi L. verbleibenden Arten genannt und die weiteren bisherigen Thlaspi-Arten entsprechend den bestehenden Abstammungsgemeinschaften neu gruppiert. Notwendige Beschreibungen neuer Gattungen und Arten sowie weiterer Sippen werden gegeben. As the result of critical investigations in the „Thlaspi”-species of Europe, Africa, and the Near East those species remaining in the genus Thlaspi L. are named. Furthermore the previous Thlaspi-species are regrouped according to the existing descendance-communities. Diagnoses of new genera and species, and other new taxa are given.

Über Glasbildung und Eigenschaften von Chalkogenidsystemen. III. Zur Glasbildung im System Germanium-Selen

Abstract: Die Glasbildung im System GeSe wird unter Angabe definierter Schmelz- und Abkuhlbedingungen beschrieben. Das mittlere Atomvolumen der Glaser nimmt mit wachsendem Germaniumigehalt ab, durchlauft bei der Zusammensetzung GeSe3ein Minimum, um danach auf einen maximalen Wert fur glasartiges GeSe2 anzusteigen. Beim Einbau von GeSe in GeSe2-Glas fallt das Atomvolumen erneut ab. Aus der durch Vergleich mit der Raumerfullung in den kristallinen Phasen ermittelten relativen Packungsdichte werden in Verbindung mit in der Literatur beschriebenen Atomverteilungskurven Ruckschlusse auf die Struktur der Glaser gezogen. Der Kurvenverlauf der Transformationstemperaturen wird in die Diskussion einbezogen. Die Glaser werden weiterhin durch ihr Rekristallisationsverhalten charakterisiert. Glass Formation in the System Germanium-Selenium. The glass formation in the system Ge—Se is investigated applying defined melting conditions and cooling rates. Starting from vitreous selenium the mean values of the atomic volume decrease when the germanium content increases. At the composition GeSe3 there is a minimum. On the other hand, the atomic volume of vitreous GeSe2 hase a maximum value but after addition of GeSe the volume gets smaller. Conclusions about the structure are drawn comparing the densities of the glasses and crystalline phases. The course of the transformation temperatures and the behaviour of recrystallization are discussed.

Zur nichtstationären Theorie der Resonanzfluoreszenz

Abstract: The time dependence of the spectral and spatial energy density of the fluorescence radiation of an atomic system generated by the resonance scattering of an intense laser pulse was calculated. Particularly the influence of the duration and the intensity of the incident laser pulse and of the atomic relaxation constants upon the fluorescence radiation has been studied.

Homogeneous broadening in a 0.63 μm single mode He-Ne laser

Abstract: The expression for inversion density in a gas laser includes an additional term if one allows elastic and/or resonant collisions among the active atoms. This term is a function of the line parametersγ 1, andγ 2 and describes the effect of homogeneous broadening on the saturated gain profile. Measurements of these parameters show that the homogeneous broadening in a 0.63 μm He-Ne laser plays an important role.

Untersuchungen an Selen‐Verbindungen. LXIV. Darstellung und Eigenschaften von Säurederivaten von Phenylselen(IV) ‐Verbindungen (C6Hs) 2SeX2, (C6H5) 3SeX

Abstract: Es wird das Reaktionsverhalten von (CsHs) 2SeBr2 und (C6H5) 3SeCl mit Silbersalzen von Sauren untersucht. Aus (C6H5) 2SeBr3 und AgY (Y = NO3, CH3CO2, CF3CO2, 1/2 SO4, CH3SO3, NCO) werden (C6H5) 2Se(NO3) 2 (C6H5) 2Se(CH3CO2) 2, (C6Hs) 2Se(CF3CO2) 2, (C6H5) 2SeSO4, (C6H5) 2Se(CH3SO3) 2 und (C6H5) 2Se(NCO) 2 dargestellt. Die Verbindungen werden durch ihr Loslichkeitsverhalten, durch ihre hydrolytische und thermische Bestandigkeit sowie durch ihre Molmasse und ihre Leitfahigkeit charakterisiert. (C6H5) 3SeCl reagiert mit AgX (X = NO3, CH3CO2) zu (C6H5) 3SeNO3 und (C6H5) 3SeCH3CO2. Studies on Selenium Compounds. LXIV. Preparation and Properties of Acid Derivatives of Phenylselenium(IV) Compounds (C6H5) 2SeX2 and (C6H5) 3SeX. Reactions of (C6H5) 2SeBr2 and (C6H5) 3SeCl with silver salts of acids are investigated. From (C6H5) 2SeBr3 and AgY (Y = N03, CH3CO3, CF3CO2, 1/2 SO4, CH3SO3, NCO) the compounds (C6H5) 2Se(NO3) 2 (C6H5) 2Se(CH3CO2) 2, (C6Hs) 2Se(CF3CO2) 2, (C6H5) 2SeSO4, (C6H5) 2Se(CH3SO3) 2 and (C6H5) 2Se(NCO) 2 are prepared. They are characterized by solubility, molecular weight and conductivity. Reaction of (C6H5) 3SeCl and AgX (X = NO3, CH3CO2) yields (C6H5) 3SeNO3 and (C6H5) 3SeCH3CO2.

Comparative urinary stone analyses. Quantitative chemical, x-ray diffraction, infrared spectroscopy and thermo-analytical procedures.

Abstract: Modern physicochemical methods, X-ray diffraction, infrared spectroscopy and thermoanalysis yield the best results in the differentiation of the constituents of urinary calculi. The comparison of 100 analyses did not bring any erroneous diagnosis, the main constituent was unambiguously ascertained. Slight differences in the results have no bearing upon therapy. The equipment needed for these determinations is very expensive. The effective and absolute time consumptions differ depending on the method. These economic factors are disregarded in the present work. The quantitative chemical analysis cannot compete with other methods, though with a 2% limit of error it is well suitable for practice.

Magnesium ammonium phosphate monohydrate--a hitherto undetected constituent of urinary calculi.

Abstract: Magnesium ammonium phosphate monohydrate, MgNH4PO4·H2O, has been detected as a constituent of urinary calculi. The substance was identified by X-ray powder diffraction analysis, and the analysis was confirmed by comparison with synthetic material. Magnesium ammonium phosphate monohydrate may occur in secondary calculi which are formed in a strongly inflamed urinary tract. A possible mechanism of formation is discussed.

[Experimental studies on the mechanism of action of both developmental-physiologically active fractions of the brain hormones of insects (activation factor I and II) of the prothoracic gland].

Abstract: 2 prothoracotropical factors (activation factor I and II) have been obtained by gel filtration techniques from brains and corpora cardiaca of the cockroachPeriplaneta americana. In contrast to activation factor II, activation factor I caused significant influence of RNA synthesis. The RNA pattern of prothoracic glands stimulated by activation factor I as demonstrated by polyacrylamide gel electrophoresis consists of different kinds of RNA. Short time incubation revealed effects on sRNA synthesis, while long time incubation demonstrated predominantly increase of ribosomal RNA synthesis. Measurements of the membrane potential of the prothoracic gland cells of the wax mothGalleria mellonella indicated an increase by activation factor II; activation factor I was without any visible effect. Our results demonstrate for the first time that the two activation factors induce different effects at cellular level.

Zur steuerung des mechanismus der kationischen copolymerisation durch solvatbeeinflussung

Abstract: Die Monomer/Comonomer-Systeme Isobutylvinylather (IBVA)/Isobutylen (IB) und Isobutylvinylather/Propylen wurden mit AlBr3 in den unpolaren Losungsmitteln Hexan bzw. Toluol in Gegenwart geringer Zusatze von dipolaren aprotischen Verbindungen, wie z. B. N,N-Dimethylformamid, Dimethylsulfoxid u.a., kationisch polymerisiert. Es wurde gezeigt, das sowohl die Natur des Zusatzes als auch dessen Konzentration, die Zusammensetzung und das Molekulargewicht des Copolymeren innerhalb eines weiten Bereiches regulieren. Fur die Copolymerisationsparameter (r1 bzw. r2) einiger Systeme wurden folgende Werte bestimmt: Fur IBVA (M1) r1 ≫ 1 und fur IB (M2) r2 ≪ 1. Mixtures of isobutylvinyl ether (IBVE) with isobutene (IB) or with propene were polymerized with aluminium bromide in toluene or hexane, in the presence of small amounts of dipolar, aprotic compounds, e.g. N,N-dimethylformamide or dimethylsulphoxide. It was found that the nature of the additive and its concentration can change the copolymer composition and the molecular weight over a wide range.–The copolymerization ratios determined for some systems conform to the generalization that r1 (IBVE) ≫ 1, r2 (IB) ≪ 1.

Über Glasbildung und Eigenschaften von Chalkogenidsystemen. II. Zur Glasbildung in den Systemen AsGeSiTe und GeSiTe

Abstract: Es wird der Glasbildungsbereich im System AsGeSiTe bei einem Gehalt von 50 At.-% Tellur beschrieben, und das Glasbildungsgebiet im system GeSiTe wird mitgeteilt. Die Transformationstemperaturen werden in Abhangigkeit von der Zusammensetzung der Glaser diskutiert. On Glass-Forming and Properties of Chalcogenide systems. Glass-Forming in the Systems AsGeSiTe and GeSiTe The glass-forming regions of the system AsGeSiTe at a content of 50 At.-% tellurium and of the system GeSiTe are described. The glass transition points are discussed in dependence from the glass composition.

Elektronenoptische Untersuchungen über die Feinstruktur des visceralen Dottersackepithels der Ratte nach intrauteriner Injektion eines Kaninchen-Antirattenplacentaserums oder eines Kaninchen-Normalserums

Abstract: Introduction: In previous immunofluorescence and electron microscopic studies it has been shown that in pregnant rats the injection of rabbit antiratplacental serum causes a damage of the placenta, particularly of the feto-placental microcirculation, connected with disturbances of the fetal development and the viability of the fetuses and newborns. On the immunofluorescence observations it was generally noticed that a specific fluorescence was present not only in the placental labyrinth, but also most prominent in the uterine wall and less conspicious in the visceral yolk sac epithelium. In rodents the yolk sac membranes arc exclusively of fetal origin. The yolk sac plays an important role in the exchange of substances between mother and fetus until term. Besides the placenta, the yolk sac represents an area of extensive and close fetomaternal contact. Immunologic reactions due to histoincompatibility between mother and fetus first affect the yolk sac epithelial cells. These aspects and the fact that there are as yet no electron microscopic studies of the yolk sac membranes after injection of an antiplacental serum gave rise to the present studies. Material and Methods: The rats used were of the Wi star strain and bred in colony. Details on standard diet and the determination of the day of pregnancy were described previously (Franke et al., 1971). Each study group consisted of 3–5 animals. At the day 16 or 18 of gestation one of the following sera was injected into the uterine cavity at a dose of 6 μl/g body weight: 1. normal rabbit serum (serum of non-immunized rabbits), 2. rabbit antiratplacental serum (titer 1: 8 or 1: 32). Determination of the titer by the double diffusion system of Ouchterlony. Detailed information on serum production, titer and specifity checking of the antiplacental serum and the intrauterine injection including the necessary surgical procedures have been given elsewhere (Oswald et al., 1971, Franke et al., in the press). All rats were sacrificed at day 19 (24–72 hrs. following the injection). Tissue samples were excised only from those yolk sacs situated next to the injection area and from the visceral yolk sac only where superficial folds were developed. After a 10 minute prefixation in ice-cold 3 per cent glutaraldehyde the tissue samples were cut into small stripes (0,1 × 0,4 mm), postfixed in the same but fresh fixative for 3 hes. followed by osmium tetroxide for the same time. All samples were embedded in Micropal. sectioned by an OmU2-microtome from Reichert, Vienna. and examined under the electron microscope model SEM III, Television-works, Berlin-Oberschoneweide. - Normal visceral yolk sac epithelium was not analysed electron microscopically, because this was already done previously (Franke et al., in press). Results: 1. Effect of antiplacental serum (titer 1: 32, 24 hrs. after injection): most remarkable is the nearly complete disappearance of the large phagosomes characteristic for all epithelial cells in the controls. Furthermore, there is a lack of invagination stages of the plasma membrane and the microvilli are partly less well developed. The originally homogeneous hyaloplasm has become more coarse and shows tendencies of vacuole formation. Likewise abnormal findings are lipid droplets in nearly every cell in large numbers. 2. Effect of antiplacental serum (titer 1: 32,72 hrs. after injection): The visceral yolk sac epithelium has changed thou roughly . All cells show signs of degeneration and early necrosis. The microvillous border has almost disappeared. The hyaloplasm is atypically finely granular and often extremly electron-dense or heav ily vacuolated. Only residues of the ER-mcmbranes can be seen. The lipid droplets are commonly markedly increased in size and number. The nuclei show typical Caryorrhexis and pycnosis. Phagosomes are an exceptional finding. More frequently, however, phagolysosome-like cell organelles are developed. One part of the mitochondria is swollen and the interior is often damaged, the other part is only slightly altered. State of the fetuses: most of them show signs of damage, especially those situated next to the injection area. In some cases antenatal death was recorded (see also Goetze, in press). 3. Effect of an antiplacental serum (titer 1: 8, 72 hrs. after injection): In comparison to the controls the most striking observation is the marked increase in the number of electron-dense phagolysosome-like cell organelles in each epithelial cell. Symptoms of cell damage were not recognized. 4. Effect of normal rabbit serum (72 hrs. after injection): All observations correspond completely to those seen in the epithelial cells after application of an antiplacental serum of low titer (1: 8). The high number of electron-dense phagolysosome-like particles also appears to be a significant feature. Discussion: The electron microscopic results reveal that the degree of fine structural alterations of the visceral yolk sac epithelium depends clearly upon the strength of the anti placental serum injected. The findings indicate that the serum of non-immunized rabbits and the weak rabbit antiplacental serum (1: 8) were pinocytosed and stored obviously in nearly equal amounts and without causing detectable alterations of the cellular fine structure. This leads to the conclusion that yolk sac epithelium has not only a nutritive, but also a protective function. The epithelial cells may be capable to act as an immunologic barrier by catching antibodies directed against fetal tissue antigens. Such antibodies are pinocytosed and later digested. That this mechanism is possible only to a limited degree demonstrate the studies with an antiplacental serum of a higher titer. The arrest of the pinocytotic activity may represent the immunologically induced primary effect, whereas the further drastic damages may to a high degree be secondary effects, due to inflammatory processes in the cross-reacting uterine wall and due to nutritive disturbances.

Untersuchungen an Selen-Verbindungen. LXII. Verbindungen des Typs C6H5SeX3 mit X = OCH3, NO3, CH3CO2

Abstract: PhSeO(OCH3) 3 (Ph = C6H6) entsteht aus PhSeBr3 und NaOCH3. Nach dem IR-Spektrum besitzt die Molekel eine verzerrte trigonal-bipyramidale Struktur, wobei zwei OCH3−Gruppen axial sowie eine OCH3−Gruppe, die Ph-Gruppe und das nicht-bindende Elektronenpaar des Selenatoms aquatorial angeordnet sind. Nach. Aussage des 1H-NME-Spektrums erfolgt auch bei −100°C rascher Austausch der axialen und aquatorialen Positionen. Aus PhSeBr3 und AgX (X = NO3, OH3CO2) entstehen auch bei −60°C nicht die Verbindungen PhSe(ONO2) 3 und PhSe(OCOCH3) 3, sondern deren Zersetzungs-produkte PhSeO(ONO) 2) + N2O5 sowie PhSeO(OCOCH3) + (CH3CO) 2O. Die Nitrat- und Acetatgruppe sind kovalent gebunden. Studies on Selenium Compounds. LXII. Compounds of the Type C6H6SeX3 with X = OCHS, NO3, CH3CO2. Reaction of PhSeBr3 (Ph = C6H5) with NaOCH3 forms PhSe(OCH3) 3. Tho infrared spectrum indicates a distorted trigonal bipyramid with two OCH3 groups in axial positions, whereas one OCH3 group, the Ph group and the nonbonding electron pair occupy the equatorial ones. The 1H-NMR spectrum indicates fast exchange of the axial and equatorial positions down to −100°C. The compounds PhSe(ONO2) 3 and PhSe(OCOCH3) 3 are not detectable down to −60°C, Reaction of PhSeBr3 and AgX (X = NO3, CH3CO2) yields only the dissociation products PhSeO(ONO2) + N2O5 and PhSeO(OCOCH3) + (CH3CO2) O, resp. The groups NO3 and CH3CO2 are covalent bonded with the Se atom.

Comparisons of the texture of amyloid, collagen and Alzheimer cells. A polarization microscopic-histochemical study.

Abstract: This investigation was performed in order to determine textural similarities and differences between variable amyloid types. Alzheimer fibrils and collagen were also compared with these structures. For this reason we used tissue specimens of secondary amyloid (so-called perireticular amyloid), primary amyloid (so-called pericollagen amyloid), senile plaques, Alzheimer cells and collagen of tendons, scars, atherosclerotic aortes, rheumatic synovial membranes and of a dura mater cerebri, and examined these fibre types by polarization optical-histochemical methods.

Untersuchungen an Selen-Verbindungen. LXVII. Die Darstellung von Amiden der selenigen Säure

Abstract: Durch die Umsetzung von [(CH3)2N]2SeO bzw. (RO)2 SeO mit NH3, CH3NH2 und H2N(CH2)2NH2 entstehen die Amide der selenigen Saure (NH2)2SeO, (CH3NH)2SeO und (CH2NH)2SeO, die nur bei tiefen Temperaturen bestandig sind. Die thermische Stabilitat der Amide nimmt in der angegebenen Reihenfolge zu. Studies on Selenium Compounds. LXVII. Preparation of Amides of the Selenious Acid By reaction of [(CH3)2N]2SeO or (RO)2SeO with NH3, CH3NH2 and H2N(CH2)2NH2 the amides of the selenious acid (NH2)2SeO, (CH3NH)2SeO, and (CH2NH)2SeO are formed which are stable only at low temperatures. The thermic stability of the amides increases in the given order.

Relationen Zwischen Protonenassoziations‐und Komplex‐stabilitätskonstanten bei substituierten Anthranilsäuren

Abstract: Es wird ein „Modell der ahnlichen Koordinationsspharen” entwickelt, das es ermoglicht, eine quantitative beziehung zwischen den Protonenassoziations- und den Komplexstabilitatskonstanten der Liganden der Typen I und XIV (s. Text) aufzustellen. Der Einflus der Substituenten X und Y auf die Protonierung und die Komplexbildung wird dabei uber den induktiven und mesomeren Effekt sowie uber den Feldeffekt erfast. Das Modell wird anhand zahlreicher experimenteller Daten uberpruft. Relations between Proton Association and Complex Stability Constants of Substituted Anthranilic Acids A “model of similar coordination spheres” is developed. From this model a quantitative relation between the proton association constants and the complex stability constants of ligands of the types I and XIV (see text) may be derived. The influence of the substituents X and Y on the Protonation and on the complex formation is reduced to the inductive and mesomeric effect and to the field effect. The complex stability constants calculated with the help of the model are compared with the experimental results.

Über den Einfluß von Elektronen-Donatoren auf die Copolymerisation von Isobutylen und Isobutylvinyläther

Abstract: Bei der kationischen Copolymerisation von Isobutylvinylather und Isobutylen werden selbst bei erheblicher Variationsbreite der Molverhaltnisse beider Komponenten statistische Copolymere mit nur geringem Isobutylenanteil gebildet. Setzt man dem Polymerisationsgemisch Elektronen-Donatoren unterschiedlicher Starke und Dosierung zu, so konnen die Monomerenanteile im Copolymerisat in weiten Grenzen variiert und durch entsprechende Wahl der eingesetzten Molverhaltnisse die Copolymerenzusammensetzungen vorausschaubar abgeschatzt werden.

Untersuchungen an Selen-Verbindungen. LXIII. Uber die Verbindungen C6H5Se(OCH3) 3−nXn [n= 1,2] und (C6H5) 2Se(OCH3) X

Abstract: Bei der Reaktion von C6H5Se(OCH3) 3 mit C6HsSeX3 (X = Br, Cl) im Molverhaltnis 2:1 bzw. 1:2 entstehen C6HsSe(OCH3) 2X bzw. C6H5Se(OCH3) X2. Aus C6HsSe(0CH3) 2Br und AgNO3 entsteht C6H5Se(OCH3) 2NO3. (C6H5) 2Se(OCH3)2reagiert mit (C6H5) 2SeX2 zu {CsH5}2Se(OCH3) X. Alle Verbindungen sind farblose bzw. gelbe kristalline Substanzen. Das Nitrat ist ionogen aufgebaut entsprechend der Formel [C6H5Se(OCH3) 2]+NO3. Es besteht ein Zusammenhang zwischen der Zahl und der Natur der Substituenten, der Lage der SeO- und CO-Valenzschwingungsbanden und der Natur der thermischen Zersetzungsprozesse. Studies on Selenium Compounds. LXIII. The Compounds C6H5Se(OCH3) 3−nXn[n = 1, 2) and (C6H5) 2Se(OCH3) X. Reaction of C6H5Se(OCH3) 3 and C6H5SeX3 (X = Br, Cl) in molar ratios 2:1 or 1:2 yields C6H5Se(OCH3) 2X and C6H5Se(OCH3) X2. resp. Reaction of C6H5Se(OCH3) 2 Br and AgNO3 yields C6H5Se(OCH3) 2NO3 which forms ionic crystals. (C6H5) 2Se(OCH3) 2 reacts with (C6H5) 2SeX2 forming (C6H5) 2Se(OCH3) X. The compounds are colourless or yellow-crystalline solids. A correlation exists between the number and nature of the substituents, the position of the SeO and CO valence vibrations of the SeOCH3 groups, and the nature of the decomposition processes.

Electromagnetic Test Fields around a Schwarzschild Singularity

Abstract: If the two invariants of an arbitrary non-static electromagnetic vacuum field are finite at the Schwarzschild radiusr=M, the field behaves atr=M+ either as a purely ingoing or as a purely outgoing wave.

In-vitro-Inkubation von Magenschleimhautbiopsien mit 3H-Thymidin

Abstract: Introduction In vitro-incubations enable among other things, studies on the proliferation kinetics and determination of various parameters of metabolism and synthesis in bioptically obtained human tissue. In the present paper the proliferation in the surface and glandular epithelia of the gastric mucosa are studied at different stages of Gastritis utilizing 3 H-thymidine which is incorporated into DNA of intermitotic cells in the S-phase. Material and Methods Incubation of the gastric mucosa particles drawn by aspiration biopsy was done in Parker-medium 199 with 10% calf serum and 5 μC/ml 3 H-thymidine. From a total number of 35 patients 2 or 3 biopsy particles per patient were incubated. Following embedding in paraffin, the autoradiographs were prepared on stripping-film AR 10; the time of exposure was 18 days. All labelled cells were counted in 16–24 sections from different levels of the biopsy particles. Results and Discussion The number of labelled cells increases simultaneously with increasing inflammation indicating regeneration processes. This is most expressive in the marginal regions of sections of gastric mucosa particles. In contrast, an intact surface of the mucosa is effective as a barrier against the penetration of the radioactive labelled precursors. Possible causes are discussed. They must be taken into consideration at in vitro-studies of mucosa particles.

Polarographische Untersuchungen an Kupfer(II)‐ und Cadmium(II)‐Chelaten vierzähliger Aminopolycarbonsäuren

Abstract: Die Kupfer(II)-Komplexe der vierzahligen Aminopolycarbonsauren H3A, H3B, H4C und H4D (Bedeutung der Abkurzungen siehe Text) werden an der Quecksilbertropfelektrode reversibel und in einer Stufe reduziert. An der Elektrodenreaktion ist jeweils ein Wasserstoffion beteiligt. Das gleiche trifft fur die Cadmium(II)-Komplexe der aromatischen Liganden H3B, H4C und H4D im pH-Bereich zwischen 4 und 5,5 zu. Bei hoheren pH-Werten gewinnt eine irreversible Elektrodenreaktion, wahrscheinlich die Reduktion der Komplexe CdB−, CdC2- und CdD2- ohne Beteiligung von Wasserstoffionen, an Bedeutung. Die Cadmium(II)-Komplexe des aliphatischen Liganden H3A und H3E (Untersuchungen von Koryta) weisen zwei polarographische Stufen auf. Davon ist die positivere kinetisch bedingt und reversibel, die negative diffusionsbedingt und irreversibel. Die zweite Stufe wird auf die Reduktion der Komplexe CdHB und CdHE zuruckgefuhrt. Zur Ermittlung der Art der Elektrodenreaktionen wurden neben Gleichstrom- auch Wechselstrompolarogramme und Polarogramme am hangenden Quecksilbertropfen herangezogen. Polarographic Studies on Copper(II) and Cadmium(II) Chelates of Quadridentate Aminopolycarbonic Acids At the dropping mercury electrode the copper(II) complexes of the quadridentate aminopolycarbonic acids H3A, H3B, H4C, and H4D (for abbreviations see text) are reduced reversibly and in one wave, one hydrogen ion participating in the electrode reaction in each case. The same is true for the cadmium(II) complexes of the aromatio ligands H3B, H4C and H4D between pH 4 und 5,5. At higher pH an irreversible electrode reaction becomes important, probably the reduction of the complexes CdB−, CdC2-, and CdD2- without any participation of hydrogen ions. With the cadmium(II) complexes of the aliphatic ligands H3A and H3E (investigated by Koryta) two polarographic waves are observed. The more positive is a reversible kinetic wave, the more negative an irreversible diffusion wave. The latter is caused by the reduction of the complexes CdHB or CdHE. For the determination of the type of the electrode reactions besides direct current polarogrammes alternating current polarogrammes and polarogrammes at the hanging mercury drop were used.