"Snow demonstrates his new inhaler (Mark I)"
"Dr Snow placed on the table an apparatus for inhaling the vapour of ether. It consisted of a round tin box, two inches deep, and four or five inches in diameter, with a tube of flexible white metal, half an inch in diameter, and about a foot and a half long, coiled round and soldered to it. There was an opening in the top of the vessel, at its centre, for putting in the ether, and afterwards attaching the flexible tube belonging to the mouth-piece. In the interior was a spiral plate of tin, soldered to the top, and reaching almost to touch the bottom. When used, the inhaler was to be put in a hand-basin of water, mixed [120/121] to a particular temperature, corresponding to the proportion of vapour that the operator might desire to give; and the caps being removed, and the mouth-tube attached, when the patient began to inhale, the air would gain the desired temperature in passing through the metal pipe; it would then come upon the surface of the ether, where it would have to wind round three or four times before entering the tube going to the mouth-piece, thus ensuring its full saturation, and preserving it at the desired temperature. There was no valve, or any other obstruction to the air, till it reached the mouth-piece, which was of the kind used in other inhalers, and contained the valves necessary to prevent the return of the expired air into the apparatus. Dr. Snow said it had been applied, in one case, at the temperature of seventy degrees, and had produced the effects of ether, very powerfully, in half a minute. In answer to a question, he said that ether, when sufficiently pure to be inhaled, would not act on tin or other metals."
"Westminster Medical Society," Lancet, 1 (30 January 1847): 120-21. An identical report appeared the day before, but without an illustration, in "Westminster Medical Society," LMG 39 (29 January 1847): 201.