Allan Kardec begins by emphasising the great importance of spontaneous physical phenomena:

The phenomena we have just described, (he refers to the preceding chapter, where the movement of objects was treated of,) are provoked, though they sometimes occur spontaneously, without the participation of the will, and even against the will, as they often become very unwelcome. On the other hand, what excludes the supposition that these phenomena are an effect of the imagination over-excited by spiritistic ideas, is that they occur among people who have never heard of them, and at a time when they least expect it. Such phenomena, which might be called natural practical spiritism, are extremely important, because they do not give rise to suspicion of collusion. It is for this reason that we recommend those who deal with spiritism to record all such phenomena of which they are aware, but, above all, to carefully verify their reality by a careful study of the circumstances, in order to make sure that they are not the playthings of an illusion or a mystification.

We fully agree with this text. The forcefulness of certain physical phenomena, of this natural practical spiritism, brings, or should bring, a plus of acceptance of these facts. However, as Kardec points out, it is necessary to be wary of imaginations and deceptions; and if this was necessary at that time, here and now it is necessary to be more cautious due to the technological progress that allows us to simulate pretended realities.

What could be the reason for such a "noisy" phenomenology?

Their main purpose was to draw people's attention to the reality of the existence of spiritual beings capable of giving such obvious signs. These manifestations, much rarer today, offered and continue to give us elements of great interest for the acceptance of the presence of the world of disembodied souls in our lives. Thus, the relevance of these rough but undeniable proofs is unquestionable.

The spontaneous manifestations are not always limited to noises and banging, but sometimes degenerate into a real uproar and disturbances. Furniture and various objects are knocked over, projectiles of all kinds are thrown from outside in, doors and windows are opened and closed by invisible hands, window panes are broken, and all this cannot be attributed to an illusion.

Often the mess is real, but at other times it is only apparent. There is a clatter in the next room, the sound of crockery falling and shattering loudly, pieces of firewood rolling on the floor. The people of the house rush in, but find everything quiet and in order. As soon as they leave, however, the commotion begins again.

Certainly the second case mentioned would be difficult to prove nowadays, since, as we pointed out before, technology offers unimaginable resources to pretend a non-existent reality.

These manifestations may be prompted by spirits of a higher order than ours, but executed by lower spirits, in order to attract the attention of the incarnate. But there are also times when the objective is to wreak some kind of vengeance upon those who are living in that place.

In any case, the dictates of prudence must always be followed and, before admitting the reality of the phenomenon, it must be ensured that it cannot be due to natural causes.

What is indispensable, however, is the presence, ostensible or occult, of a mediumnity with physical effects in the vicinity of the place, in order for the production of the phenomenon to be possible. It is because of this circumstance, opportunely pointed out by Kardec, that poltergeists are not as abundant as might be expected (since there can always be some spirit nearby with the intention of disturbing), if the presence of someone with this unusual type of mediumistic faculty were not necessary. In addition to these material difficulties in the realisation of these manifestations, there is also the prohibition of their realisation which may be imposed by higher spirituality in some cases.

This chapter recommends what would be the best way to proceed in circumstances of this kind: to evoke mediumistically the spirit responsible for the phenomenon in order to find out what he intends by his action. In reality, however, this is not so easy to do, for it requires a serious, experienced and flexible medium. So what could be done in such a situation if mediumistic help could not be obtained to solve the problem? We always have at our disposal the resource of sincere prayer, voluntary mental help, and the systematic and patient reading and commentary of moralising texts aloud. By these actions, these spirits are given correct information and, with perseverance, can be convinced of the error of their ways. Nor can a drastic solution be ruled out, which would be to leave the place, although this is not always effective (the spirit may accompany its victims), nor does it solve the problem existing in that place.

(...) Kardec rightly pointed out, that poltergeists are not as abundant as might be expected (since there may always be some spirit around with a mind to disturb), if the presence of someone with this unusual kind of mediumistic faculty were not necessary.

Contribution phenomena

Let us complete this article by talking about one of the most curious, rare and remarkable phenomena of physical effects: the phenomenon of the contributions. Let us consider some of Kardec's precisions in this respect:

It consists of the spontaneous contribution of objects that do not exist in the place where the observers are. These are almost always flowers, sometimes fruit, jams, jewellery, etc.

Let us say at the outset that this phenomenon is one of those which lend themselves most readily to imitation, and we must therefore be on our guard against trickery. We know how far the art of conjuring can go when it comes to experiences of this kind. However, even if we do not have to fight with a professional, we can easily be deceived by a skilful and self-interested manoeuvre.

Therefore, we must always be careful, careful and careful. In spiritism we cannot afford to accept any phenomena of which we are not reasonably certain of their reality, for the harm that may be done far exceeds the satisfaction of presenting a pretended, apparently evidential demonstration.

Very little is said about these manifestations nowadays, but it is useful to know the basics about them in order to be able to properly judge any that are referred to us.

In the first place, it must be borne in mind that these are individual phenomena; that is to say, they will be produced by the action of a single spirit with the assistance of a single medium. Furthermore, it seems that the amount of energy resource provided by the medium must be very abundant (what Kardec and his collaborators called animalised fluid), so that not all mediums with physical effects will be suitable for this type of experience.

How do spirits proceed to bring an object into an enclosed place?

The Spirit "envelops" and thus "invisibilises" the object to be brought with the combination of its own energetic resources and the medium's animalised fluid. When the time comes to show the object, it simply removes this enveloping combination and the object is revealed. In principle, any object could be brought; but since the spirit, by its action, is able to nullify the effect of gravity for that object, it is evident that the heavier the object, the more resources will be required on the part of the spirit, as well as the greater the amount of the medium's animalised fluid. This means that not every spirit will be able to perform this task successfully, since it represents a great quasi-physical effort for him.

Allan Kardec asks a very relevant question to the spirit Erastus (who collaborated in the meetings of the Paris Society):

Is it possible for an object to be brought into a completely closed place? In a word, can the Spirit spiritualise a material object, so that it penetrates matter?

"This question is complex. Spirit can render the objects it brings invisible, but not penetrable. It cannot break the aggregation of matter, for that would imply the destruction of the object. By rendering it invisible, the Spirit can bring it in whenever it wishes, and detach it only at the appropriate moment, to make it appear."

It is obviously not possible to "spiritualise" matter. Kardec wants to indicate whether a temporary transformation of this object would be possible in order to make it penetrable. However, as he qualifies the spirit, it is not possible to endow the element to be brought with this characteristic. Therefore, in reality, this will be more a phenomenon of transporting something material, invisibilised and introduced through any physical opening in the room where this manifestation takes place, than a contribution to a totally closed and impenetrable place. However, in this respect, Erastus makes the following statement:

Things happen differently with regard to the objects which we compose. Since we only introduce into them the elements of matter, and since these elements are essentially penetrable, and since we ourselves penetrate and pass through the most condensed bodies as easily as the sun's rays pass through glass, we can perfectly well say that we have introduced the object into a place, however closed it may be. But that only happens in this case.

That is to say, a genuine phenomenon of contribution would involve the spirit itself forming this object, which, being made up of ‘mental matter’, would then have the property of penetrability in a completely enclosed place. All this makes it all the more exceptional that such an event should actually occur.

One might think that, given the spectacular nature of these manifestations, if there were a proliferation of this phenomenology, this would be enough to convince the sceptics. However, nothing could be further from the truth.

"You will tell me, of course, that these phenomena are useful in convincing unbelievers. But you must know that, if you had no other means of conviction at your disposal, you would not have even a hundredth part of the spiritism that exists today. Speak to the heart, for it is through the heart that you will gain the greatest number of serious conversions. Should you judge it expedient, for certain persons, to use material facts, at least present them in such circumstances that they cannot give rise to any false interpretation, and, above all, do not depart from the normal conditions of these facts, for if they are presented in bad conditions they furnish arguments to unbelievers, instead of convincing them.’"

Thus it is really that which affects feeling, that which gives rational answers, that which helps to understand the true purpose of Life, that can convince the most suspicious. Material phenomenology, for those who do not want to be convinced, would possibly be taken for a hoax or a conjuring trick. On the other hand, what touches on reason and emotion has a much more direct and convincing effect. Indeed, the spiritism philosophy and ethics have this characteristic. This does not, of course, imply any disparagement of these striking physical manifestations, which obviously have their raison for existence.