This is a serious study of the claims advanced in favour of paraldehyde as a hypnotic since its introduction into medicine in 1882. The ideal soporific which shall with certainty and without delay secure an untroubled refreshing sleep, approaching natural sleep as nearly as possible; the soporific which shall neither lose its efficacy nor accumulate its effects, and which shall, moreover, be easily dispensed and agreeable to take;—such a drug, like the philosopher's stone, has yet to be discovered. Among soporifics, however, as things are, paraldehyde can claim many virtues, and further experience and better knowledge have only strengthened its position. In the Freiburg Asylum, Dr. Bumke says that paraldehyde has more than held its ground against sulphonal, trional, and hedonal, and that it and scopolamin are now alone employed.