Reasoning about optional and non-harmful factors acting on the body

Let's now talk about factors that are optional and non-harmful, that is, those that are not inherent in nature and are not contrary to nature. These are things that come into contact with the body, but not air, for air is essential for the body, but, for example, bathing in a bathhouse, all kinds of rubbing, etc. Let's start with general considerations about these factors and say the following.

Things that act on the human body from the outside by contact act on it in two ways: either because the subtle parts of their substance penetrate into the pores due to the inherent ability of them to sink and pass deep, or because the organs draw them in through the pores; sometimes both these processes mutually contribute to each other. And sometimes this is accomplished without any confusion with the body, just by the pure quality of the factor that changes the state of the body. This quality sometimes acts in fact, as for example, a cooling lubricant, which actually cools, and a warming lubricant, which actually warms, or, say, warming poultices, which actually warm, and sometimes because this quality is inherent in the factor potentially, but the inherent warmth excites active force in him and brings it from a potential state to an active one. In some cases, things act due to their specific properties.

Things that change the body when touched and do not change it when taken internally include, for example, onions: if it is applied externally it ulcerates, but does not ulcerate when taken internally. And some things act in the opposite way, for example, white lead: if you drink it, it produces a big change, but if you smear it with it, it has no effect. Some things work both ways.

The reason for the action of factors of the first type is one of the following six. The first reason is that if a substance like onion is introduced into the body, the digestive power hastens to break it down and changes its nature, without leaving it intact for a period during which it can produce its effect and cause ulceration within.

The second reason is that such substances are in most cases taken internally in a mixture with something else, the third is that it is also mixed in the feeding vessels with liquids that fill it and break its power.

The fourth reason is that such a substance remains outside in one place, but inside it moves all the time; the fifth is that on the outside it firmly adheres to the body, but on the inside it only touches without sticking to the organs. The sixth reason is that when such a substance is inside, the natural force receives it at its disposal, and the excess is immediately expelled, and the benign substance is converted into blood.

As for the difference between lead white and onions, the reason is that the particles of lead white are dense and do not pass into the pores from the outside, and if they do pass, they do not go deep to the places where the pneuma exits and to the main organs; if you take them internally, then the opposite is true. And it should also be added that the poisonous nature contained in lead white is excited only by the extreme influence of the innate warmth within us, and such an influence does not arise from the very fact of contact from the outside.

In the Book of Simple Medicines you will often encounter discussions related to this area.