The nmr chemical shift of the acid proton of acetic acid in CCI4 has been investigated. The observed chemical shift can be quantitatively explained by assuming that acetic acid is present as an equilibrium mixture of monomers, cyclic dimers, linear dimers, and linear polymers. The temperature dependence of these equilibria is also studies. Low-temperature chemical shift measurements in cyclopentane support this model and corroborate the assignment of the chemical shift of the cyclic dimer.

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We were able to detect hemihypertrophy of a fetus in a routine prenatal ultrasound examination. The presence of hemangiomas and varicose veins in the hypertrophied left lower extremity at birth enabled us to diagnose the Klippel-Trenaunay-Weber syndrome. The possibility of a congenital arteriovenous fistula causing the constellation of findings was ruled out by a nuclear flow study and a thorough physical examination. A computerized tomographic scan revealed that the hemangiomas were superficial in the hypertrophied left lower extremity and did not interrupt the deep muscle bundles.

The CO2 concentration measured at Mauna Loa Observatory exhibits a characteristic afternoon decrease thought to be due to the local island biosphere. Several afternoon increases occurring during the past 11 yr may be explained in terms of drought and soil conditions in specific sections of the island. The previously reported annual increase of 0.6–0.7 ppm (1961–1968) in background CO2 concentration appears to be increasing, the 1968–1972 increase being in excess of 1 ppm/yr.

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