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The application of cryogenic technology to medical problems has resulted in the development of methods for freeze-preserving two of the cellular components of blood. Cryopreservation of different cell types, e.g., nucleated leukocytes and non-nucleated erythrocytes, cannot be achieved successfully unless techniques designed to prevent cellular damage induced by freezing are used. Unprotected cells can, depending upon the rate of freezing, be damaged in a variety of ways, principally through dehydration, solute effects, and ice-crystal formation. When cryoprotective compounds, such as glycerol, DMSO, etc. are used and the cooling rate is controlled, cell damage can be circumvented, however. A slow cooling rate with an intracellular additive has been found better for preserving nucleated white blood cells, whereas very rapid freezing techniques have in general proven more successful for preserving non-nucleated red blood cells for transfusion. Ultra-rapid freezing of blood in the form of droplets is a useful means of preserving red cells for blood-group studies. Storage and prolonged preservation of biological specimens have been more successful at cryogenic temperatures (e.g., −196 deg C) than at higher storage temperatures (e.g., −85 deg C).

PREVIOUS HISTORY. —The patient was 26 years of age and weighed 96 pounds before the uterine contents were removed. She asserted that, when 2 years old, she was very sick with a fever, after recovering from which she did not walk for over a year. She was perfectly normal at birth and grew until 5 years old; since then she has grown broader, but very little taller. EXAMINATION. —On examination the patient was found to be 41 inches in height. The head, face and neck were normal and the intelligence above the average. The trunk was small, but not especially deformed. From the spine of the seventh cervical vertebra to the tip of the coccyx measured 20½ inches. The extremities were markedly short, stumpy and deformed. The arm from the shoulder to the tip of the middle finger measured 14 inches. The legs were approximately 16 inches long.Pelvis: The

Marti1and Eugster et al.(ref. 2 and unpublished work) recently discovered 81Kr, the first cosmic ray produced radionuclide heavier than the Ni–Fe group, in stone meteorites. By measuring only the isotopic composition of Kr, they evaluated the radiation ages of the meteorites as follows where Tris the radiation age, λ81is the decay constant of 81Kr = 3.25 × 10−6yr−1(refs. 3 and 4) and P(MKr) is the production cross-section of the nuclide in question. The exponential term becomes negligible if Tr≧2 m.y.

THE indictment is that “ the economic theory of to-day is useless because it is unintelligible ; because, after all their arduous studies, the economists cannot be relied upon not to give diametrically opposite diagnoses and prognoses of the same situation... ; because the economists feed on their own tails by busying themselves with the analysis of imaginary worlds which they themselves have invented ; and because they are passing off as the result of purely scientific inquiry what is in reality no more than a partisan advocacy of particular social policies”.