Mr. WYNNE, M. P. breathed five quarts of diluted nitrous oxide, without any sensation. Six quarts produced fulness in the chest, heat in the hands and feet, and sense of tension in the fingers, slight but pleasant sensations. Seven quarts produced no new or different effects. Mr. MACKINTOSH several times breathed nitrous oxide. He had sense of fulness in the head, thrillings, tingling in the fingers, and generally pleasurable feelings. Mr. JOHN CAVE, Junr. from breathing four quarts of nitrous oxide, felt sensations as from superior wine, and general pleasant feelings. Mr. MICHAEL CASTLE, from five quarts, experienced sensations of heat and thrilling, general spirits heightened considerably as from wine; afterwards, slight pain in the back of the head. Mr. H. CARDWELL, from five quarts, had feelings so pleasurable as almost to destroy consciousness; almost convulsed with laughter; for a long time could not think of the feeling without laughing; sensation of lightness for some time after. Mr. JARMAN, from five quarts, great pleasure, laughter, certainly better spirits, glow in the cheeks which continued long. The gentleman who furnished the preceding detail, had heard of the effects of nitrous oxide, and was prepared to experience new sensations: I therefore gave him a bag of common air which he respired, believing it to be nitrous oxide; and was much surprised that no effects were produced. He then breathed five quarts of nitrous oxide, and after the experiment, gave this account of his sensations. Rev. W. A. CANE, after inhaling the gas, felt the most delicious sensations accompanied by a thrill through every part of his body. He did not think it possible so charming an effect could have been produced. He had heard of the gas; but the result of the experiment far exceeded his expectations. _May 6th_, 1800. * * * * * Mr. JOSEPH PRIESTLEY from breathing nitrous oxide, generally had unpleasant fulness of the head and throbbing of the arteries, which prevented him from continuing the respiration. Dr. BEDDOES mentioned in his Notice, that Mr. JOSIAH WEDGWOOD and Mr. THOMAS WEDGWOOD experienced rather unpleasant feelings from the gas. Mr. JOSIAH WEDGWOOD has since repeated the trial, the effects were powerful, but not in the slighted degree pleasant. Mr. R. BOULTON and Mr. G. WATT have been much less affected than any individuals. Many other persons have respired the gas, but as their accounts contain nothing unnoticed in the details, it is useless to particularise them. The cases of all the males who have been unpleasantly affected since we have learnt to prepare the gas with accuracy, are related in this Section and in the last Division. Those who have been pleasurably affected after a fair trial and whose cases are not noticed, generally experienced fulness in the head, heat in the chest, pleasurable thrillings, and consequent exhilaration.