WITH AN INTRODUCTION BY HOWARD MARKS. Once upon a time opium (the main ingredient of heroin) was easily available over the chemist's counter. The secret of happiness about which philosophers have disputed for so many ages could be bought for a penny & carried in the waistcoat pocket: portable ecstasies could be corked up in a pint bottle. Paradise? So thought Thomas de Quincey but he soon discovered that 'nobody will laugh long who deals much with opium'.