PHYSICAL PROPERTIES OF ACIDS.

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We have divided the acids into three classes, viz.

1. Acids whose bases are unknown, or undecomposableacids.

2. Acids composed of two bases.

3. Acids composed of more than two bases.

The bases which become acid by the union of oxigen are ca-pable of being united to it in various degrees. When the oxigen-ation is complete they are called perfect acids. But if they arenot saturated with oxigen, they mostly appear in a state of lessacidity. In the new nomenclature the termination IC is givento the complete oxigenation of these bodies, and the terminationOUS when they present themselves in an imperfect state of com-bination with oxigen. Hence by the name of sulphuric acid,we mean sulphur completely saturated with oxigen; and by thename sulphureous acid, we understand sulphur not saturatedwith cxigen.

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GENERAL PHYSICAL PROPERTIES OF ACIDS.

Acids are either in the solid, liquid, or gazeous state. Theyexcite a peculiar sensation on the palate called sour. They changemost of the blue vegetable colours red. Most of them unite towater in all proportions, and many have so strong an attractionfor that fluid, as to be incapable of appearing in the solid form.They all combine with alcalies so strongly as to disengage themfrom many other substances. They mix with the earthy andmetallic substances, and form combinations attended with nume-rous interesting phenomena; upon the due explanation of whicha great part of the science of chemistry depends.

Remark. ..It must be noticed however, that every acid doesnot possess all the properties here enumerated, but all possess asufficient number to distinguish them from other substances;and this is the only purpose which artificial arrangement canpossibly answer.