As a matter of fact, the table shows that, although the volume of legal manufacture for 1951 reached the lowest level in five years, the amounts found in the illicit traffic in the same year aggregated to the highest total during the same period. Moreover, reports from governments during the last two years indicated that, thanks to stricter measures of control over manufacture of and trade in heroin put into effect by various governments, diversions from legal into illicit channels due to thefts, robberies, forged prescriptions or laxity in respect of issuance of medical prescriptions have been reduced to the minimum. If legal manufacture no longer forms an important source of supply to the illicit traffic in heroin, an explanation of this continuing nefarious traffic and its sources of supply must be sought elsewhere. Accordingly, an analysis is made in this article not only of the principal illicit markets throughout the world, as far as official information is available, and of the quantities involved, but also of the routes followed of the countries of origin and of the clandestine manufacture. The world markets, by countries and continents, and the quantities of seizures in the post-war years compared with those of 1936, are shown in the table on page 46.
Country kg gr. kg gr. kg gr. kg gr. kg gr. kg gr.
In 1951, it decreased to 2 kg 900 gr. The 1951 figure was almost six times that of 1936, which was 10 kilogrammes. Seizures in Canada were made up of small quantities. The total increased steadily in the post-war years. From 530 grammes in 1946, it rose to 1 kg 970 gr.