Mrs. S. a delicate lady, liable to nervous affections who had heard of the cases just detailed, chose to breathe the gas. By three quarts she was thrown into a trance, which lasted for three or four minutes. On recovering, the could give no account of her feelings, and had some languor for half an hour afterwards. These phænomena have rendered us cautious in administering the gas to delicate females. In a few instances however, it has been taken by persons of this class, and even by those inclined to hysterical and nervous complaints with pleasurable effects. Miss L. a young lady who had formerly had hysterical fits, breathed a quart of nitrous oxide with three quarts of common air without effects. Two quarts of nitrous oxide with one of common air produced a slight giddiness; four quarts of nitrous oxide produced a fit of immoderate laughter, which was succeeded by slight exhilaration, her spirits were good throughout the day, and no depression followed. Miss B. Y—— and Miss S. Y—— both delicate but healthy young ladies, were affected very pleasantly; each by three quarts of nitrous oxide, the first time of respiring it. Miss B Y—— continued exhilarated and in high spirits for some hours after the dose. Miss S. Y—— had a slight head-ache, which did not go off for some hours. Mrs. F. inclined to be hysterical, breathed four quarts of nitrous oxide mingled with common air. She was giddy and described her feelings as odd; but had not the slightest languor after the experiment. III. _Observations on the effects of Nitrous Oxide, by_ DR. BEDDOES. Neither my notes nor my recollection supply much in addition to what I formerly stated in the _Notice of Observations at the Pneumatic Institution_. _Longman._ The gas maintains its first character as well in its effects on me, as in the benefit it confers on some of the paralytic, and the injury it does or threatens to the hysterical and the exquisitely sensible. I find that five or six quarts operate as powerfully as ever. I seem to make a given quantity go farther by holding my breath so that the gas may be absorbed in a great degree without returning into the bag, and therefore, be as little heated before inspiration as possible.—This may be fancy. After innumerable trials, I have never once felt lassitude or depression[226]. Most commonly I am sensible of a grateful glow _circum præcordia_. This has continued for hours.—In two or three instances only has inhalation failed to be followed by pleasurable feeling, it has never been followed by the contrary. On a few occasions before the gas was exhausted, I have found it impossible to continue breathing. [226] Of the facts on which Brown founded his law of indirect debility, no prudent man will lose sight either in practising or studying medicine. They are incontrovertible.—And our new facts may doubtless be conciliated to the Brunonian doctrine.