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PROOFS OF THE PROPERTIES OF

mit a mixture of three parts of hidrogen gas and one of sulphure-ous acid gas, through a Wedgwood's tube in a state of ignition,sulphurated hidrogen gas will be evolved, and sulphur depositedat the extremity of the tube, opposite to that through which thegas is made to pass.

Rationale. ..Part of the hidrogen at such a temperatureunites to the oxigen of the sulphureous acid gas to form water,the sulphur is consequently left uncombined; another part (orat least the excess) of the hidrogen dissolves a portion of the sul-phur and becomes converted into sulphurated hidrogen gas.

Remark. ..The two last experiments are well calculated todemonstrate the nature of sulphureous acid gas. In the first, itbecame changed into sulphuric acid by the addition of oxigenat a high temperature. In the other, hidrogen gas decomposesthe sulphureous acid gas, at the same temperature, by takingfrom it that portion of oxigen which kept it acid, and the sul-phur is disengaged.

Experiment VII.

Formation of sulphate of ammonia ly mingling sulphureous acidgas and ammoniacal gas.

Let sulphureous acid gas be mixed with ammoniacal gas overmercury, a beautiful white cloud will be formed by their com-bination, heat is liberated and both gases gradually assume thesolid state, forming sulphate of ammonia. If the gases havebeen pure the mercury rises almost to the top of the vessel.

If the sulphureous acid gas be presented to the ammoniacalgas the cloud is formed at the bottom, and gradually rises to thetop ; but if the ammoniacal gas be poured in last, the cloud risesimmediately to the top. These consequences naturally resultfrom the ammoniacal gas being the lightest.

RATioNALF...The white cloud formed in this experiment issulphate of ammonia, which originates from the strong attraction