Multi-packer hydraulic tests and radioactive tracer experiments carried out in boreholes in the Carnmenellis granite have shown that the flow of water through the rock is largely confined to narrow zones separated by zones of very low permeability. Correlation of the hydraulic data with geological data from oriented cores has shown that most of the flow is associated with discrete geological features, including pegmatitic and other veins, and elvan (quartz-feldspar porphyry) dykes, characteristic features of the granite of the area. Joints have also been found to conduct water, particularly in the upper 250 m of the granite. The permeability of the granite has been found not to be simply a function of fracture frequency, long sections of highly fractured rock having no associated flow under test conditions. While flow paths have been found to become less frequent with depth, flow rates do not vary over the depths studied, the highest flow rate recorded at the site being associated with a vein at 637 m. Water-conducting fractures have been found to have certain preferred orientations which vary with depth. A set striking 155°C is particularly well developed in the upper 250 m of the granite. This orientation is significant in that it is parallel to the cross-courses in the nearby mineralized belt with which the younger (Tertiary) mineralization tends to be associated and from which thermal brines issue into several local mines. These fractures are also approximately parallel to the maximum horizontal stress which affects the granite and which appears to be responsible for the selective opening of joints of certain orientations.

giving potassium supplements to elderly patients where their need is not urgent. Since the absorption of fluid from the infusion site is slow, we do not recommend this method for giving potassium when large amounts are needed urgently. There seems to be no danger of hyperkalemia with the method used here.Although hypodermoclysis is suitable for use in nursing homes, we feel that subcutaneous potassium infusions should be given only in hospitals until more experience is gained.We would like to thank Cilla Gerber, Ilana Elroy, and the other members of the nursing staff for their help and co-operation. I

No abstract

SUMMARY Twenty patients undergoing treatment with aurothiomalate for rheumatoid arthritis (RA) were studied for the presence of gold in all urine specimens passed over four days and for gold in the serum of blood drawn by venous section at 10-00, 16-00, and 22-00 hours on a single day of the study. Specimens of saliva collected at the same times as the blood specimens were also analysed for (total) gold content. Eighteen patients showed rhythmic urinary gold excretion. Variations were observed in the serum levels for total, free, and protein bound gold at different times of the day and night together with similar variations in the salivary total gold levels. It was established that a possible relation exists between urinary gold, serum gold, and salivary gold such that at times of higher urinary gold excretion the serum gold levels (total, free, and protein bound) and the total salivary gold levels were decreased. Conversely, at times of lower urinary gold excretion serum and salivary gold levels were increased.Key words: gold therapy, aurothiomalate, circadian rhythms. tin, mercury, and zinc) t); hence the possibility of a rhythmic presence of gold was investigated. Patients and methodsTwenty new patients with RA receiving gold therapy collected aliquots of all urine specimens passed over four days and noted the times of micturition and the volume of each specimen. On one day of the study each patient collected specimens of saliva around the time of micturition. On the same day each subject had blood withdrawn by venous section at 10-00, 16-00, and 22-00 hours. The urine and saliva specimens were analysed for gold content by atomic absorption -spectrophotometry (AA), and the blood specimens were analysed for total, free, and protein bound gold by AA before and after ultrafiltration of the serum. All specimens were analysed in duplicate.

Radon is a natural radioactive gas produced by the decay of uranium and thorium in rocks and soils. High surface radon concentrations are commonly associated with high levels of uranium in underlying rocks. High radon levels can also occur in groundwater, even in rocks with normal crustal uranium concentrations. The discharge of groundwater via faults and fractures can produce radon anomalies unrelated to the distribution of uranium. The surface distribution of radon is therefore influenced by the distribution of uranium and of transport pathways along faults and fractures. The principal radon isotope (Rn-222, half-life 3.825 days) is capable of migrating significant distances from its source, both as a gas and in solution. In the gaseous form radon can migrate into houses where, in high concentrations, it can represent a health hazard. The distribution of radon in streams in several areas of southwest England has been investigated. The results show a clear association of high radon levels with the uranium-enriched granite of the region, although this may simply reflect the high fracture permeability of the granite rather than its uranium enrichment with a strong influence of major fracture systems. With regard to radon as a potential health hazard, both source and transport pathways must be identified if high-risk areas are to be located. Surveys of radon in surface waters may provide a useful and speedy technique for the broad identification of such areas.