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plete combustion by the electric sparknearly two measures of oxygene, and theyformed nearly one measure of carbonic acid.

Sulphur heated strongly and repeatedlysublimed in a portion of it freed from oxy-gene by phosphorus, produced a consider-able enlargement of its volume, sulphurettedhydrogene was formed, and charcoal pre-cipitated ; and it was found that the volumeof the sulphuretted hydrogene produced,when it was absorbed by solution of potassa,was exactly double that of the fire-dampdecomposed.

It did not act upon chlorine in the cold;but, when an electric spark was passedthrough a mixture of 1 part of it with 2 ofchlorine, there was an explosion, with adiminution to less than one-fourth, andmuch charcoal was deposited.

The analysis of specimens of gas sentto my friend John George Children, Esq.by Dr. Clanny, afforded me similar results;but they contained variable quantities ofcarbonic acid gas and azote.

Different specimens of these gases weretried by the test of exposure to chlorineboth in darkness and light: they exhibited

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