Vapors and Exhalations

The air-aether in the pores of terrestrial bodies are more agitated at one time than another. This can be caused by the presence of the sun or some other cause.

This also agitates the small earth-aether particles of these bodies more strongly.

The small ones or those shaped or situated in a way that makes them easily separable from their neighbors.

This causes them to scatter here and there and rise into the air.

This is simply because they cannot find any other place to go.

It is not because they have an inherent inclination to ascend.

This is similar to how dust in a field rises when it is pushed and agitated by the feet people passing by, making them go up into the air.

More dust rises when more people walk on them.

The action of the sun raises vapors quite high, since it always extends at the same time over half of the earth and stays there all day.

These small particles that are thus raised into the air by the sun should mostly have the shape of water because they are the most easily separable from the bodies that they are in.

These alone I will call “vapors”. These are different from the more irregular shaped ones I call “exhalations”, as I know no more proper term.

Included in the exhalations are those with nearly the same shape as the water particles but are more subtle. These make up spirits or life waters that can easily catch fire.

I will exclude the earth-aether particles that compose the body of air that are:

• divided into several branches
• so subtle

There are earth-aether particles that are a bit coarser and also divided into branches.

• They cannot leave the hard bodies which they are a part of by themselves.
• But they can be driven by fire, for example, which drives them all out in smoke.

When water slips into their pores, the water can often release these earth-aether particles and carry them up with it.

• This happens in the same way that the wind, passing through a hedge, carries away the leaves or straw entwined among its branches.

Vapors always occupy much more space than water even if they are made of the same small particles.

This is because when these particles make up water, they only move strongly enough to bend and intertwine. They slide against each other, as represented at A.

However, when they take the form of vapor, their agitation is so great that they quickly turn around in all directions and stretch out to their full length, so that each has the force to push away all its similar parts that tend to enter the small sphere it describes. This is represented at B. It is similar to how, if you spin the pivot LM fast enough, through which the cord NP passes, you will see that this cord stands in the air, straight and stretched, occupying all the space within the circle NOPQ, in such a way that no other body can be placed there without being immediately struck with force and driven out. However, if you move it more slowly, it will coil around the pivot itself and thus will no longer occupy as much space.

These vapors can be more or less compressed or expanded, more or less hot or cold, more or less transparent or obscure, and more or less humid or dry at different times.

First, when their parts, no longer being agitated strongly enough to remain stretched out in a straight line, begin to bend and draw closer to one another, as represented at C and D.

Or when they are confined between mountains or between the actions of various winds that, being opposed, prevent each other from agitating the air, or under some clouds, they cannot expand into as much space as their agitation requires, as seen at E.

Or finally, when using the greater part of their agitation to move together in the same direction, they no longer whirl around as strongly as usual, as seen at F, or emerging from space E, they generate a wind that blows toward G. It is clear that the vapors they compose are denser or more compressed than when none of these three things happen.**

Aassuming the vapor at E is as agitated as that at B, it must be much hotter, because its parts, being more compressed, have more force.

Just as the heat of red-hot iron is much more intense than that of coals or flames. This is why we often feel a stronger and more stifling heat in summer when the air is calm and equally pressed from all sides, indicating rain, than when it is clearer and more serene. The vapor at C is colder than that at B, even though its parts are slightly more compressed, because I assume them to be much less agitated. Conversely, the vapor at D is hotter because its parts are assumed to be much more compressed and only slightly less agitated.

The vapor at F is colder than that at E, although its parts are neither less compressed nor less agitated, because they are more aligned in moving in the same direction, which prevents them from shaking the small parts of other bodies as much. Just as a wind that always blows in the same direction, though very strong, does not shake the leaves and branches of a forest as much as a weaker one that is less steady.**

You can verify through experience that it is in this agitation of the small parts of terrestrial bodies that heat resides. If you blow strongly against your fingers held together, you will notice that the breath from your mouth will seem cold above your hand, where it passes very quickly and with equal force, causing little agitation.

But you will feel it quite warm between your fingers, where it passes more unevenly and slowly, agitating their small parts more. Similarly, you always feel it warm when you blow with your mouth wide open, and cold when you blow with it almost closed. This is why impetuous winds are usually felt as cold, and there are hardly any warm winds that are not slow.

The vapors represented at B, E, and F are transparent and cannot be distinguished by sight from the rest of the air because, moving very quickly and in the same manner as the subtle matter that surrounds them, they do not prevent it from receiving the action of luminous bodies but rather receive it along with them.

In contrast, the vapor at C begins to become opaque or obscure because its parts no longer obey the subtle matter enough to be moved by it in all directions. The vapor at D cannot be as obscure as that at C because it is hotter.

As you can see in winter, the cold makes the breath or sweat of heated horses appear as a thick, dark smoke, whereas in summer, when the air is warmer, it is invisible. One should not doubt that the air often contains as much or more vapor when none is visible as when some are.

How could it be otherwise, without a miracle, that in hot weather and at midday, the sun shining on a lake or a marsh fails to raise many vapors?

Especially since it is noted that at such times, the water evaporates and diminishes much more than in cold and overcast weather.

The vapors at E are more humid, meaning more likely to convert into water and wet or moisten other bodies as water does, than those at F. The latter, on the contrary, are dry, as they strike with force the moist bodies they encounter, being able to displace and carry away the water particles present, thereby drying them out.

This is why we experience that impetuous winds are always dry, and there are no humid ones that are not weak.

One could also say that the vapors at E are more humid than those at D because their parts, being more agitated, can better penetrate the pores of other bodies to make them moist. However, in another sense, they could be said to be less humid because the excessive agitation of their parts prevents them from easily taking the form of water.**

As for exhalations, they are capable of many more diverse qualities than vapors because there can be more differences among their parts.

But it will suffice here to note that the coarser ones are almost nothing but earth, such as can be seen at the bottom of a vase after allowing snow or rainwater to settle, and the most subtle ones are nothing but these spirits or life waters, which always rise first from the bodies being distilled.

Among the intermediate ones, some partake of the nature of volatile salts, and others of oils, or rather the fumes that come out when they are burned.

Even though most of these exhalations rise into the air mixed with vapors, they can still easily separate afterward, either by themselves, as oils separate from the water with which they are distilled, or aided by the agitation of winds that gather them into one or several bodies, in the same way that village women, by churning their cream, separate the butter from the buttermilk.

Often, simply by being more or less heavy and more or less agitated, they settle in a lower or higher region than vapors do. Generally, oils rise less high than life waters, and those that are just earth rise even less than oils.

However, none settle lower than the parts that make up common salt, and although they are not properly exhalations or vapors because they only rise just above the surface of the water, since it is through the evaporation of this water that they come there, and there are many noteworthy things about them that can be conveniently explained here, I do not wish to omit them.**