Oxygene, which is capable of being respired for a much greater length of time than any other gas, except common air, finally destroys life; first producing changes in the blood, connected with new living action.[185] [184] As appears from the experiments of Dr. Beddoes; likewise those of Mr. Watt. [185] As appears from the experiments of Lavoisier and Dr. Beddoes; and as will be seen hereafter. After experiments, to be detailed hereafter, made upon myself and others, had proved that nitrous oxide was respirable, and capable of supporting life for a longer time than any of the gases, except atmospheric air and oxygene, I was anxious to ascertain the effects of it upon animals, in cases where its action could be carried to a full extent; and to compare the changes occasioned by it in their organs, with those produced by other powers. II. _On the respiration of Nitrous Oxide by warm-blooded Animals._ The nitrous oxide employed in the following experiments, was procured from nitrate of ammoniac, and received in large jars, filled with water previously saturated with the gas. The animal was introduced into the jar, by being carried under the water; after its introduction, the jar was made to rest on a shelf, about half an inch below the surface of the water; and the animal carefully supported, so as to prevent his mouth from resting in the water. This mode of experimenting, either under water or mercury, is absolutely necessary, to ascertain with accuracy the effects of pure gases on living beings. In some experiments that I made on the respiration of nitrous oxide, by animals that were plunged into jars of it opened in the atmosphere, and immediately closed after their introduction, the unknown quantities of common air carried in, were always sufficient to render the results perfectly inaccurate. Animals suffer little or nothing by being passed through water. That the phænomena in these experiments might be more accurately observed, two or three persons were always present at the time of their execution, and an account of them was noted down immediately after.