COMBINATION OF SULPHUR WITH METALS.

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much water is decomposed by the joint action of the ingredients,that the oxigen from the water (its caloric at the same timebeing set free) forms with the sulphur a considerable portion otsulphuric acid which by the further assistance of water, furnish-ing oxigen, attacks the iron. Here then are two sources ofcaloric and hidrogen gas (the other principle of water) which inits nascent state seizes on a portion of sulphur, and forms anothernew and inflammable compound called sulphurated hidrogen gas;those decompositions taking place through the whole mass occa-sion the heat, swelling, bursting, and discharge of clouds ofsulphureous vapour. While these effects are rapidly going on,the temperature increases sufficiently to kindle a particle of sul-phur, which communicating with the inflammable gases producesan explosion, occasionally repeated as fresh quantities of gas areevolved, the whole being now in a state of combustion burns aslong as the sulphur or any other inflammable matter remains.

There is no doubt that the combustion of those enormousmasses of bituminous pyrites, which are deposited in the bowelsof the earth produce volcanos on the same principles. The de-composition and action of the constituent principles of the waterupon the component parts of the pyrites fully determine all thephenomena.

Experiment III.

Accension of sulphur and metals.

The union ot sulphur with copper and other metals at a lowtemperature is attended with some remarkable phenomena. Inorder to exhibit this experiment mix three parts of copper filings,and one of sulphur reduced to powder, intimately together ; in-troduce this mixture into a glass tube or Florence flask, andheat it gradually over a lamp or coal fire. After the mixture hasbeen heated to a certain degree, it begins to swell, and a smallignited spark becomes first visible at the bottom of the glass ves-

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