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Direct arterial pressure and electrocardiogram have been measured continuously over a period of 24 hours in 15 patients. Observations have been made on the behaviour of these variables during 30 separate episodes of motor car driving. The patients were divided into three groups: (1) five normotensive subjects, (2) five patients with essential hypertension who were not receiving therapy, and (3) five patients with angina pectoris who were either normotensive or hypertensive.In all but one subject, apart from variable changes in heart rate, no significant arrhythmias or S-T segment changes were observed in the electrocardiogram. The arterial pressure remained remarkably stable throughout the driving period in all three groups and there was no significant difference between the levels of blood pressure at the beginning and end of a journey. There were short periods of raised arterial pressure during driving related to such episodes as overtaking, but these quickly returned to baseline levels. Two patients experienced anginal pain during driving.It is concluded that motor car driving does not have such a pronounced effect on the blood pressure as might have been thought.

A total of 100 outpatients in the North-East of Scotland were given a simple anaesthetic of propanidid, nitrous oxide, oxygen, and halothane. The study was undertaken to assess what happened to patients when they left hospital after outpatient surgery. An outpatient questionnaire was used, and results show that 31% of patients journeyed home unaccompanied by a responsible person, 73% of car owners drove within 24 hours of the operation, and 9% drove themselves home. Postoperative symptoms of drowsiness (26%), headache (27%), nausea (22%), and dizziness (11%) were recorded, and a higher incidence of symptoms was recorded when surgery exceeded 15 minutes. A new form for outpatient operative procedures in Aberdeen has been devised with modern legal implications in mind.

A double-blind controlled comparison of four commonly-used tranquillizing drugs (haloperidol, amylobarbitone sodium, chlordiazepoxide, and trifluoperazine) against placebo was made in their effects on the performance of volunteers during three low speed vehicle-handling tests. The drugs (with the exception of haloperidol) significantly altered driving behaviour though they did not seem to interact significantly with alcohol. There is, therefore, a strong possibility that such drugs will similarly alter driving performance in patients taking them for therapeutic purposes. Since, as these experiments also show, those affected may be subjectively unaware of it, and routine clinical screening is not sensitive enough to detect them, physicians should warn patients of the probability that their driving performance will be affected by such drugs, particularly during the first few days that they are taken.

The status of the epileptic applicant for a licence to drive a private motor vehicle has changed from total prohibition through a stage of partial approval subject to medical assessment to the present conditional right to a driving licence. We report a study of a series of patients which shows that many and probably most epileptics have obtained driving licences by concealment of their condition, yet the new regulations continue to expect true declarations. It is suggested that, in common with applicants for a public service vehicle or a heavy goods vehicle driving licence, the applicant for a licence to drive a private motor vehicle should provide a medical report of fitness. The epileptic should be included in a general category of medically restricted drivers subject to individual medical assessment.

Electrocardiograms were recorded in experienced motor-car drivers accustomed to busy city traffic while driving their own cars along familiar routes. The majority with normal hearts or a history of coronary heart disease increased their heart rates; brief periods when the rate exceeded 140/min. were recorded in both groups. ST changes not caused by tachycardia developed in 3 out of 32 normal drivers. Of 24 drivers with coronary heart disease 13 increased their ST and T abnormalities, the changes being gross in six. A further five developed multiple ventricular ectopic beats. Two coronary drivers experienced anginal pain and two left ventricular failure. Healthy motor-racing drivers increased their heart rates to 180/min. in the few minutes before the start of a race and to above 200/min. while racing.Little or no change in the plasma catecholamine levels was noted in three coronary subjects immediately after a city drive compared with resting levels. All the racing drivers showed a considerable increase in noradrenaline, and in one instance adrenaline, immediately after racing.Persons in whom angina is easily provoked when driving or who are in borderline left ventricular failure should be advised not to drive.

The incidence of 'alcoholism' is difficult to determine. This difficulty reflects the absence of a universally accepted definition of the disease. Various attempts have been made to base inter national comparisons upon such indices as alcohol consumption per person, death rates from 'alcohol related' diseases, hospital admission rates for 'alcoholism', and even conviction rates for 'drunk enness'. No problem would arise if all of these yardsticks displayed a high and consistent inter correlation, between regions and over time. In fact the widely used Jellinek formula assumes this to be the case and, although this method of comparing the incidence of alcoholism internationally has been criticized (Sundby, 1967), its use has influenced numerous discussions of national levels of alco holism. The present paper has been prompted by the authors' knowledge of the Irish scene. In view of the prominence of the emigrant Irish in several studies of alcoholism, the case of the Irish in Ireland deserves more attention than it has received, especially since (as is argued in the course of the present paper) it calls into question the feasibility of developing any consistent indices of the incidence of alcoholism. Some aspects of this topic have already been discussed among research workers in Ireland (Lynn and Hampson, 1970; Walsh, 1970). Literary and historical sources provide abundant evidence that the Irish have long been regarded as exceptional in their abuse of alcohol. Commen tators have been virtually unanimous in applying the stereotype of the drunken Irishman. A syste matic discussion of the literary and anthropological evidence, together with an attempt to provide a theory of Irish alcoholism, have been provided by Bales (1962). This paper attempts to compare the Irish case with as large a number of other countries as is feasible, using quantifiable indices that have been proposed by various authors as possible yardsticks of the prevalence or incidence of alcoholism. In this way it is hoped not only to place the Irish case in perspective but also to evaluate the reliability of these yardsticks in international comparisons of alcoholism. The measures that will be considered are

In a previous communication we reported data supporting the recommendation that a red road traffic signal should have an intensity of 200 cd for optimum recognition from 100 m when the signal is seen against a very bright sky (104cd/m2). This confirmed the earlier result of Boisson and Pagès. The present paper extends the data to include (a) the effect of signal size on optimum signal intensity for a practical range of angular diameters (4.1 to 16.5 min of arc), and (b) the effect of background luminance for a range of luminances of 1.5 ft-L to 2250 ft-L. The results show that optimum signal intensity is independent of signal size and that spatial summation by the visual system is complete. However the same data demonstrate a failure of spatial summation when a conventional threshold criterion (probability of seeing the signal 0.5) is used. It is shown that smaller signals will be more effective than larger ones of the same intensity if their intensity is less than optimum. Optimum signal intensity is shown to be a linear function of background luminances greater than 10 ft-L. A graph relating optimum signal intensity to signalling range for various background luminances summarises the experimental data.