It is probable that nitrous oxide may be combined with ammoniac, by means of double affinity. Perhaps sulphate of ammoniac and the combination of potash with nitrous oxide mingled together in solution, would be converted into sulphate of potash and the compound of nitrous oxide, and ammoniac. X. _Probability of forming Compounds of Nitrous Oxide and the Alkaline Earths._ I attempted to combine nitrous oxide with lime and strontian, by exposing sulphites of lime and strontian with excess of earth, to nitrous gas; but this process did not succeed: the diminution took place so slowly as to destroy all hopes of gaining any results in a definite time. Sulphite of potash is decomposable by barytes, strontian, and lime;[164] consequently it was impossible to employ this substance to effect the combination. As the dry sulphures, when well made, convert nitrous gas into nitrous oxide, it is probable that the union of the earths with nascent nitrous oxide may be effected by exposing nitrous gas to their sulphures, containing an excess of earth. [164] See the above mentioned elaborate memoir of Fourcroy and Vauquelin. Perhaps the combination of nitrous oxide with strontian may be effected by introducing the combination of potash and nitrous oxide into strontian lime water. It is probable that nitrous oxide may be combined with clay and magnesia, by exposing these bodies, mingled with sulphite of potash or soda, to nitrous gas. XI. _Additional Observations on the combinations of Nitrous Oxide with the Alkalies._ A desire to complete physiological investigations relating to nitrous oxide, has hitherto prevented me from pursuing to a greater extent, the experiments on the combination of this substance with the alkalies, &c. As soon as an opportunity occurs, I purpose to resume the subject. The observations detailed in the foregoing sections are sufficient to show that nitrous oxide is capable of entering into intimate union with the fixed alkalies: and as the compounds formed by this union are insoluble in alcohol, decomposable by the acids, and heat, and possessed of peculiar properties, they ought to be considered as a new class of saline substances. If it is thought proper, on a farther investigation of their properties, to signify them by specific names, they may, according to the usually adopted fashion of nomenclature, be called _nitroxis_: thus the _nitroxi of potash_ would signify the salt formed by the combination of nitrous oxide with potash. Future experiments must determine the different affinities of nitrous oxide for the alkalies, and alkaline earths.