methods of obtaining carbonic acid gas.

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any other animal is immediately killed if his nose be thrustinto it.

The carbonic acid, existing naturally in the state of gas, maybe collected by filling bottles with water and emptying theminto the atmosphere of this gas ; the gas takes the place of thewater and fills the bottles, which must then be corked.

Carbonic acid gas is likewise formed during fermentation ; onaccount of its great weight it occupies the apparently emptyspace, or upper part of the vessel in which the fermenting pro-cess is going on. It may in this case be collected in a mannersimilar to that above.

Carbonic acid gas is also obtained during the reduction ofmetallic oxids, and during the deflagration of nitrates with com-bustible bodies, as shall be noticed in another part of thiswork.