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The Schiff bases α- N -methyl-{S}-methyl-β- N -(2-hydroxyphenyl)methylendithiocarbazate o-HO.C 6 H 4 .CH = NNMeC(=S)SMe (HONMeS), its 3-methoxy derivative (3-MeOHONMeS), 1-(2-hydroxyphenyl)-2,3-diaza-4-methylthio-5-thiahexa-1,3-diene, o-HO.C 6 H 4 .CH = NNC(SMe) 2 (HONSMe) and its 5-chloro and 5-bromo derivatives (5XHONSMe; X = Cl, Br) were prepared. By the loss of a proton the Schiff bases act as uni-negatively charged ONS tridentate ligands. The complexes Ni(ONMeS)X (X = Cl, Br, NCS) are diamagnetic and square-planar, while the complex Ni(ONMeS) 2 is paramagnetic and octahedral. The palladium complex Pd(ONSMe)Cl was also isolated. the copper complexes Cu(ONMeS)NO 3 , Cu(ONSMe)NO 3 , and [Cu(ONMeS)py]ClO 4 display normal magnetic behaviour. The compound Cu(ONMeS)BF 4 has an anomalously low moment (0.88 B.M.) at room temperature and the moment decrease to 0.38 B.M. at 93°K due to antiferromagnetic interaction. The compound Cu 2 (3MeOONMeS)Cl 3 also displays antiferromagnetic interaction between the two copper atoms of the dimer. The complexes Cu 3 (ONMeS) 2 Cl 4 and Cu 3 (ONSMe) 2 Cl 4 most likely have a linear trimeric structure; the magnetic data for the latter compound fit an equation for a linear trimer with three antiferromagnetically interacting copper atoms. The compounds Cu(5ClONSMe)Cl and Cu(5BrONSMe)Cl are monomeric with normal magnetic moments.

Absolute multiplet strengths of transitions between 2p43p-2p43d terms of Ne+ sequence have been obtained by the nuclear charge expansion method within the Hartree-Fock approximation and with mixing of terms of different L-S geneology. Comparison is made with known results for NaIII.

Self consistent field molecular orbital calculations with limited configuration interaction have been made for two tetrazanaphthalenes for four different sets of values of two electron repulsion integrals. Results show that even with the same parameter set, the present method yields results which agree better with experimental results than those obtained from Pariser—Parr calculation with the same parameter set. It is shown that the approximation of treating two electron repulsion integrals between distant nitrogen and carbon π-orbitals as that between two carbon π-orbitals leads to poor results for the first excited state but reasonable results for the higher excited states.

Despite their high cost, carbon fibres are an attractive choice as reinforcement for reactive matrices such as cement because of their chemical inertness at ambient temperatures. Since these fibres have very high specific strength and elastic modulus, only a small volume per cent of the fibre is required for producing composites having strengths similar to those of commercial asbestos cement sheets. A 3 vol % addition of the high-modulus carbon fibre to cement results in a two-fold increase in the modulus of elasticity and a five-fold increase in the tensile strength over the values of the unreinforced matrix. But no significant improvement in impact strength has been observed at these low levels of fibre addition.

In the presence of certain metal salts 3,3,5-trimethyl-1,3,4-thiadiazolidine-2-thione, 5,5-dimethyl-1,3,4-thiadiazolidine-2-thione, and 5-(2-pyridyl)-1,3,4-thiadiazolidine-2-thione undergo rearrangement to yield neutral metal chelates of the tautomeric Schiff bases, respectively, α-N-methyl-β-N-isopropylidentithiocarbazate (N-Me-Sh) isopropylidentithiocarbazate (N-Sh), and β-N-(2-pyridyl)methylendithiocarbazate (N-N-SH). The compounds isolated were M(NMe-S) 2 (M = Ni, Cu, Pd), M(N-S) 2 (M = Ni, Pd), Co(N-S) 3 . H 2 O, and Ni(N-N-S).

Absolute multiplet strengths for dipole transitions between 1s4l 1,3 L and 1s4l′1,3 L′ of the helium isoelectronic sequence have been calculated in the L-S coupling scheme exactly up to first order in perturbation theory within the context of the Z -1 expansion method. Calculated f values for helium transitions are compared with accurate variational results. f values for Li+ transitions are obtained using experimental transition energies.

P-method calculations have been carried out on two non-planar dioxins to study the applicability of the method to such systems. The E.S.R. spectra have also been calculated using standard techniques for open-shell systems to test further the π-electron separability theorems.

Calculations have been made for Hafner's hydrocarbons using a refined form of the Huckel MO method in which dependence of ‘Coulomb’ integral on charge density and ‘resonance’ integral on bondlength via bond order have been allowed for in a selfconsistent manner. Bondlengths, π → πk spectra, stability and reactivity of the molecules as given by the refined MO method have been compared with the simple Huckel MO method results.

The difficulties encountered in the performance of the Blalock-Taussig 1 and Potts 2 anastomoses in certain children led to the development 3 and popularization in the United States 4,5 of intrapericardial anastomosis between the ascending aorta and the right pulmonary artery. Although this shunt is applicable to almost all patients, an occasional patient has an anatomic arrangement that does not allow this anastomosis. In such an instance it may be possible to create a shunt between the ascending aorta and the main pulmonary artery.

Persistent truncus arteriosus is not a common anomaly. Two percent of children with potentially correctable variants (types I, II and III) have reduced rather than increased pulmonary blood flow. It is possible to provide palliation for such infants with a systemic to pulmonary anastomosis, allowing them the chance for a second stage total correction at a later age. Such a palliative procedure is described in a 6 day old infant with cyanosis.

To the Editor.— Persistent truncus arteriosus in an uncommon congenital cardiac anomaly with a poor prognosis. Recent advances in surgical technique have made corrective surgery possible in some children who survive until the age of 3 or 4 years. For this reason palliative procedures designed to tide these children over until that time are of increasing interest. The following is a report of an unusual palliative operation in a neonate with a persistent truncus arteriosus, reduced pulmonary blood flow, and severe cyanosis. Report of a Case.— The patient was admitted to the Boston Floating Hospital at 6 days of age, weighing 6 lb 8 oz. She was obviously cyanotic but in no acute distress. Pertinent physical findings were a normal heart size and a pansystolic murmur over the entire precordium with an early diastolic component. Cardiac catheterization revealed a large ventricular septal defect, with equal pressures in both ventricles and