Dr. Blake inhaled about six quarts of the air, was affected during the process of respiring it with a slight degree of vertigo, which was almost immediately succeeded by a thrilling sensation extending even to the extremities, accompanied by a most happy state of mind and highly pleasurable ideas. He felt a great propensity to laugh, and his behaviour in some measure appeared ludicrous to those around him. Muscular power seemed agreeably increased, the pulse acquired strength and firmness, but its frequency was somewhat diminished. He perceived rather an unpleasant taste in the mouth and about the fauces for some hours afterwards, but in every other respect, his feelings were comfortable during the remainder of the day. _December, 30th._ To MR. DAVY. XIII. _Detail of_ MR. WANSEY. I breathed the gas out of a silk bag, believing it to be nitrous oxide, and was much surprised to find that it produced no sensations. After the experiment, Mr. Davy told me it was common air. I then breathed a mixture of common air and nitrous oxide. I felt a kind of intoxication in the middle of the experiment, and stopping to express this, destroyed any farther effects. I now breathed pure nitrous oxide; the effect was gradual, and I at first experienced fulness in the head, and afterwards sensations so delightful, that I can compare them to no others, except those which I felt (being a lover of music) about five years since in Westminster Abbey, in some of the grand choruses in the Messiah, from the united powers of 700 instruments of music. I continued exhilarated throughout the day, slept at night remarkably sound, and experienced when I awoke in the morning, a recurrence of pleasing sensation. In another experiment, the effects was still greater, the pulse was rendered fuller and quicker, I felt a sense of throbbing in the head with highly pleasurable thrillings all over the frame. The new feelings were at last so powerful as to absorb all perception. I distinguished during and after the experiment, a taste on the tongue, like that produced by the contact of zinc and silver. HENRY WANSEY. XIV. _Detail of_ MR. RICKMAN. On inhaling about six quarts, the first altered feeling was a tingling in the elbows not unlike the effect of a slight electric shock. Soon afterwards, an involuntary and provoking dizziness as in drunkenness. Towards the close of the inhalation, this symptom decreased; though the nose was still involuntary held fast after the air-bag was removed. The dose was probably an undercharge, as no extraordinary sensation was felt more than half a minute after the inhalation. J. RICKMAN. XV. _Detail of_ MR. LOVELL EDGWORTH.