The committee having fully examined the boy, and a number of independent witnesses, as to the facts, soon set about a scientific investigation of the true causes of of the phenomenon. The first step, of course, was to examine the lad's eye with the modern ophthalmoscope, an invention of Professor Helmholtz, of Heidelberg, a few years ago, by means of which the depths of this organ can be explored, and the smallest variations from a healthy or normal condition instantaneously detected. The mode of using the instrument is as follows: The room is made perfectly dark; a brilliant light is then placed near the head of the patient, and the rays are reflected by a series of small mirrors into his eye, as if they came from the eye of the observer; then, by looking through the central aperture of the instrument, the oculist can examine the illuminated interior of the eyeball, and perceive every detail of structure, healthy or morbid, as accurately and clearly as we can see any part of the exterior of the body. No discomfort arises to the organ examined, and all its hidden mysteries can be studied and understood as clearly as those of any other organ of the body. This course was taken with John Palmer, and the true secret of his mysterious power of vision detected in an instant. On applying the ophthalmoscope, the committee ascertained in a moment that the boy's eye was abnormally shaped. A natural, perfect eye is perfectly round. But the eye examined was exceedingly flat, very thin, with large iris, flat lens, immense petira, and wonderfully dilated pupil. The effect of the shape was at once apparent. It was utterly impossible to see any object with distinctness at any distance short of many thousands of miles. Had the eye been elongated inward, or shaped like an egg--to as great an extent, the boy would have been effectually blind, for no combination of lens power could have placed the image of the object beyond the coat of the retina. In other words, there are two common imperfections of the human organ of sight; one called _myopia_, or "near-sightedness;" the _presbyopia_, or "far-sightedness." "The axis being too long," says the report, "in myopic eyes, parallel rays, such as proceed from distant objects, are brought to a focus at a point so far in front of the retina, that only confused images are formed upon it. Such a malformation, constituting an excess of refractive power, can only be neutralized by concave glasses, which give such a direction to rays entering the eye as will allow of their being brought to a focus at a proper point for distant perception."