Part 49 (2/2)

What is the cause of bodies floating on liquids?

It is an established law of nature, that all substances which weigh less than an equal bulk of any liquid, will float on the surface of this liquid Thus a cork will float on water, while a stone sinks to the bottohter than water; and the stone is not heavier than the _whole_ of the water, but more so than a portion of water of its _own bulk_,--and thus it sinks in it Stones also differ in their weight or gravity: for instance, sohter_ than water Iron, brass, indeed, nearly all substances, except gold and platina, will float upon hter than this liquid

What is the cause of bodies being either solid, liquid, or aeriform?

When the principle of _attraction_ prevails, it causes them to become solid; when caloric prevails, they become aeriform Fluidity is, apparently, a medium between the two

How is the state of Solidity in bodies accounted for?

The particles of all bodies are subject to two opposite powers, _repulsion_ and _attraction_; bethich they remain in equilibriuest, the body remains in a state of solidity; but if heat destroys this force, the particles lose their cohesion, and the body ceases to be solid

_Cohesion_, act of sticking together, union of the constituent parts of a body

Which is supposed to be the most natural state of all bodies?

Solidity; for by the _combination_ of caloric with them we can reduce reatest number of _liquid_ substances take a _solid_ foreals and forases show this disposition to beco some _combination_

Explain the terms _Repulsion_ and _Attraction_

Repulsion is a peculiar property in the particles of ives them a constant tendency to recede from each other Attraction is an unknown force, which causes bodies or their particles to approach each other The particles of all bodies possess this property, which causes them to adhere, and preserves the various substances around us fro in pieces

What different kinds of Attraction can you uished into that which takes place between bodies at sensible distances, and that which manifests itself between the _particles_ of matter at insensible distances

Give an example of the first kind of attraction

One of the most familiar instances of attraction at sensible distances is seen in the descent of heavy bodies to the ground When a stone is lifted up in the hand, the earth's attraction, which previously caused it to remain at its surface, is overcome; but, as soon as the hand is withdrawn, the stone falls to the earth The force which causes this is called the _attraction of gravitation_, or siravitation_

How is the second kind of attraction, or that between the particles of bodies, subdivided?

Into the _attraction of aggregation_, or _cohesion_; and _chemical attraction_, or _affinity_ The former takes place between particles which are _similar_, and the latter between those which are _dissimilar_ All the operations of chemistry are founded upon the force of affinity which Nature has established between the particles of different kinds of matter, and which enables the che more or less from the substances by whose union they were formed

Is it, then, necessary for chemists to understand the relative nature of all substances?