WHEREVER we look in Nature, we come across examples of duality in material objects, and their presence does not fail in the field we occupy now. You have already met them in the case of the crystals, the magnets, the two halves of animals and men, where you always found on one side reddish-yellow od-light with disagreeable sensations of lukewarmness, and on the other side blue light with pleasant sensations of coolness. But the contrast appears in innumerable cases among the odic phenomena; it belongs to the very essence of that force.
This time let us take the simple substances of chemistry as our starting-point. Give your sensitive in turns a small phial of potassium and another of pulverized sulphur, placing them in his left hand. You will shortly receive his pronouncement that the former is having a sickly, disagreeable effect upon his feelings, and the latter a cool and pleasant one. Do the same with sodium, gold, platinum, mercury, and copper, on the one side, and selenium, iodine, phosphorus, tellurium, and arsenic on the other, and you will get the sickly, disagreeable effect from the former elements and the cool effect from the latter, a little stronger or a little weaker in the case of each.
You can proceed to make use of this graduated difference of odic strength in the simple substances for their tabulation in a series, at one end of which stands potassium as the most disagreeably lukewarm of all, and at the other end oxygen as the coolest of all; and when you carefully consider the series you have constructed, you will be astonished to find that, with trifling departures, it agrees with the series chemistry gives us in reference to the power of affinity to oxygen, known as the electro-chemical series [or series of atomic weights]. We have arrived at the same result along quite another path, namely, an equivalent series to which we must give the name of the od-chemical series.
Is it not surprising in the highest degree that a simple, unschooled girl, by the mere feeling in her fingers alone, is able within one hour to classify all the elements in Nature into a series, the construction of which has cost the greatest minds and the most learned men of our times more than half a century of tireless industry and the utmost efforts of their mental acumen? The great Berzelius, the creator of the electro-chemical system, had a profound sense of this fact when I laid the proofs before him in Carlsbad in the year 1845; but since his death surviving chemists have not thought so trifling a matter worthy of any further attention. One physiologist even has not wanted the courage to accuse the dead Berzelius of senility, because he had expressly and publicly assumed the patronage of these results of my researches.1 To help out the impetuosity of his own judgment, he needed nothing less than the modest assurance that Berzelius had on this occasion lost the use of his senses.
Of course the amorphous bodies, each taken by itself, make no exhibition of dual characteristics in this odic series, and must be regarded in each instance as unipolar, pretty much as the electrical scientists regarded soap as unipolar. The series, however, embraces them in their universality, and, taking them in this as a collective unit of the world of matter, the amorphous substances serve to emphasize the contrast in which soft, sickly sensations are produced in the sensitive hand at one end of the series and sensations of coolness at the other. Odic polarity exists in the world of matter; and, as the warm-felt substances on the left are the electropositive and the cool-felt substances on the right the electronegative, I must in the like sense and as a matter of consistency name the former odpositive and the latter odnegative.
Among composite substances, I have found the alkalis and alkaloids and everything marked by the alkaline characteristics to be odpositive, and on the other hand the haloid salts and the greater number of the oxides and acids to be odnegative, the organic substances such as rubber, starch, many of the heavy oils, and paraffin also, occupying in this respect a middle position.
In the matter of crystals, I have found that the side on which they started their growth always declares itself to the sensitive's left as sickly-warm to the touch and red-yellow to the sight, while the upper peak to which they continued their growth expresses itself as cool and blue-lit. This rule can be traced as far as the fibrous crystallizations, and up to the point of the torpid congelations where the crystalline structure itself ceases almost to be traceable. According to rule, then, the cleavage line of the crystal is odpositive, and the peak odnegative.
As to the magnet, its southward pole feels tepid to the sensitive's left and shows him a red light; that is to say, it is odpositive. Its northward pole is similarly sensed as cool and blue-lit; it is therefore odnegative. (Some physicists, but not all—see Liebig's Manual of Chemistry, v., p. 34—give the northward pole of the magnetic needle as magneto-positive, without furnishing any definite reason for their so doing. In view of odic data I must doubt the accuracy of this. Odpositive and electro-positive bodies go hand in hand, as we have seen, and magneto-positive bodies must keep in step with them; consequently the northward pole of the needle, which shows a blue light, can only be magneto-negative.) Heat, chemical reaction, and sound, have in the course of the previous investigations shown purely odnegative effects, and friction only odpositive. Researches into the odic contrasts must be extended further in regard to this point.
Polarized sunlight is odpositive in the refracted, and odnegative in the reflected, rays. In the spectrum the red, orange and yellow rays, and the rays ranged under red are all odpositive the blue, violet and chemical rays are odnegative. The same holds good for the lunar spectrum; and it even holds good for the weak spectrum of an Argand lamp.
The animal, and in particular the human, body shows itself positively odic on the whole of the left side from the summit of the cranium to the toes, and negatively odic on the whole of the right side. This shows itself most strongly in the toes and fingertips, and especially at the roots of the finger-nails, the seats of the most vital organic activity in the whole hand. Man is consequently polarised in regard to breadth. He possesses, however, other, though less strongly prominent, odic axes, namely, an axis of length and an axis of thickness, the discussion of which, however, I must refrain from in the restricted space allotted to this journalistic correspondence.
You may confirm yourself in your convictions by a few more easy experiments. Place a sheet of unused, medium-blue paper before a sensitive, and make him look at it first with the left, then with the right, eye in rotation, each time covering the eye he is not using. He will find the glance with the left eye pleasant, and with the right eye unpleasant. The left eye is odpositive and the blue tint works, as we already know, odnegatively; unlike agencies therefore met, and the effect was a pleasant one. In the other case, in which the right eye looked upon the blue, like agencies met, and the sensation of the effect was disagreeable.
Check the experiment with a sheet of orange-coloured paper; you will always get the same results, but vice versa as regards the eyes. You also see, however, from this delicate experiment, that the disagreeableness of the yellow and the pleasantness of the blue to sensitives is more especially based upon the view taken by the left eye, and that the effect upon the consciousness is predominant upon this side, and notably more important than the effect upon the right. [Note this obiter dictum as important.]
Look with your right eye at a short distance into the left eye of the sensitive, and he will raise no objection. (It is to be understood that while this takes place the other two eyes are to be closed.) Now look with your left eye into his left, and he will at once grow uneasy, and will not allow himself to be detained for half a minute. He will not be able to endure your glance; and, if you wish to make him, he will turn away. Should he be a high-sensitive, a short optical fixation of that sort will have such an unpleasantly strong effect upon him that in a few seconds later he will see nothing more out of that particular eye; indeed, it will often happen, if you force him to continue, that he will have to vomit. Left looking into left makes " like " pairing, and as such becomes unendurable to him.
Is odic dualism ascertainably present in the opposition of the two sexes? I put this question to Nature by means of the following simple experiment: I stationed a man and a woman opposite a female sensitive, and set a glass of water in the right hand of each. After six minutes, during which the water must have been negatively odified, I got the sensitive to taste from each glass. She found both cool, but the one she received from the man's hand far cooler and more agreeable than that which she received from the woman's. Upon this I stationed the pair opposite a male sensitive and went through the same proceeding. He, however, found the water from the woman's hand the cooler. You see clearly: man and woman stand in odpolar opposition.
You have no doubt remarked that I have always requisitioned your sensitive's left hand for these experiments in the sense of feeling and never his right. I must now make you clear as to the reason. " Cool " and " lukewarm " are not absolute effects of outward stimulus to the subject of excitability, but only relative effects, in relation to one specified side of the body; on the other side the sensation the opposite. But to prevent confusion of any sort entering into my descriptions, I made all the experiments only in relation to one side, and that side the left, because effects as a rule are stronger and more clearly marked on that side, and are also in consequence perceived with a more special precision. I might just as well have chosen the right side: the results would have been the same, only vice versa as regards lights and sensations.2