1. 1 History of Solvent Abuse The practice of deliberately inhaling various gases or vapors in order to induce an altered state of mood or sensibility is not new. As noted repeatedly in other reviews (eg, Cohen, 1973; Novak, 1980), it was recognized in early Greek civilization as an adjunct to divination; indeed, it has now become customary, if not obligatory, to refer to the Oracle at Delphi before considering the more recent history of the subject. According to legend, the priestess at the Temple at Delphi would achieve communion with the Gods by inhaling the naturally-occurring gas that emanated from a fissure in a rock. Inhalation would induce a trance-like state. Her mystical observations and utterances while in this state were interpreted by the Temple Prophet and issued as divine pronouncements to those seeking guidance. Incenses, perfumes and spices have probably always been used in ceremonial worship and religious ritual. However, in sofar as it is possible to make the distinction, these substances have been used primarily for their aromatic qualities rather than for their intoxicating effects. The recreational use of gases and vapors dates from the end of the eighteenth century and may be seen as a concomitant of the scientific advances that preceded the industrial revolution. Following the synthesis of nitrous oxide by Sir Joseph Priestley in 1776, the potential uses of the gas were explored in depth by Sir Humphrey Davy.

Statistical Questions in Evidence-based Medicine is a book of questions and answers about the statistical principles and methods used in medical research. Based entirely on material published in the medical literature and popular media, it will prove invaluable to medical students, doctors, nurses, medical researchers and others concerned with medical data. This book is a companion volume to the new 3rd edition of An Introduction to Medical Statistics but can also be used in conjunction with the 2nd edition or with other good texts. Short excerpts of material from published papers or summaries of their results are presented with questions. These test and develop the reader's understanding and interpretation of statistics and extend the reader's research and critical appraisal skills, thus encouraging an evidence-based approach. Questions are presented on the left-hand page with detailed answers on the right-hand page. Answers include references to core material in An Introduction to Medical Statistics. The book is intended as a series of examples for self-teaching but could also be read as a series of case studies with detailed commentaries. The questions are clearly graded, using icons, in terms of difficulty and undergraduate or postgraduate level. The book is easy to use and a model of clarity for the reader.