632 MEDICAL JURISPRUDENCE stomach full of food. Alcohol reaches its maximum concentration in the blood within approximately an hour and a half after it is taken, and this concentration is ordinarily proportional to the amount consumed. After absorption, alcohol is distributed almost uniformly in all the organs and tissues except fat and bone, but the rise and fall in its concentration is slower in the brain, spinal cord and cerebrospinal fluid than in the blood and other tissues. It disappears very slowly, so that it is found in the blood for about twenty hours after it is drunk.7 Over 95 per cent of the alcohol ingested is oxidized to carbon dioxide and water, and the remaining portion is eliminated unchanged mainly by the lungs and kidneys. It has been ascertained that alcohol appears in the urine within half-an-hour of its ingestion.8 There is close relationship between the concentration of alcohol in the blood and the degree of alcoholic intoxication. Carter and Southgate9 have also demonstrated that the concentration of alcohol in the urine is proportional to that of the blood under all conditions, and that the mean ratio of alcohol in the urine to alcohol in the blood one hour after taking the alcohol is 1.35. Hence it is necessary to analyse the blood or urine for the estimation of alcohol concentration in cases where persons have been accused of being drunk while creating disturbance in streets or driving motor cars. It must, however, be remembered that the examination of urine for the determination of alcohol is more advantageous, 'inasmuch as the alcohol concentration in urine is more constant than that in the blood which is likely to vary owing to its oxidation in the tissues. Certain substances such as acetone, ether, paraldehyde, etc. are at times present in the blood, and are likely to be determined as alcohol, and thus vitiate the test. Besides, it is much easier to obtain a sample of urine than that of blood for examination. i Evans and Jones10 have shown that the concentration of alcohol in urine [1 is so precise that it gives an accurate indication of the minimum quantity of alcohol consumed. They have also shown that the consumption of one fluid ounce of whisky under the most favourable conditions gives a maximum concentration of 0.024 per cent alcohol in the urine, while the consumption of a pint of beer will give a concentration of 0.037 per cent. Thus, a con- centration of 0.3 per cent alcohol in the urine means the consumption of at least 12J fluid ounces of whisky or 8 pints of beer. It is generally believed that persons with a concentration of 0.1 per cent alcohol in the blood appear to be gay and vivacious, and those with a con- centration of 0.15 per cent alcohol in the blood are regarded as fit to drive a motor vehicle. This concentration of alcohol in the blood is regarded as a presumptive limit of safety, and may result from the rapid consumption of 8 ounces of whisky or 4 to 5 pints of beer. Persons with a concentration of 0.2 per cent alcohol in the blood show symptoms of moderate intoxication, those with from 0.2 to 0.4 per cent are probably drunk and those with more than 0.5 per cent are dead drunk or deeply comatose. When the amount of alcohol approaches 0.6 to 0.7 per cent or more in the blood death usually ensues from asphyxia. It is legal offence for a person to drive a motor vehicle with a blood alcohol level above 0.05 per cent in Norway, above 0,08 per cent in Sweden, and above 0.10 per cent in Denmark. 7. Mellanby, Brit. Medical Research Council, Special Report Series No 31 8. Carter and Southgale, Transactions, Med-Legal Society, Vol XX. p. 44 'Le9al Society> v°L **•p-54-see ais° '