Page:Popular Science Monthly Volume 47.djvu/399

Rh known that the products of fermentation and putrefaction found as a result of faulty assimilation of food may act as irritants, either in the way of repressing normal impulses or exaggerating feeble sensory impressions, to the end that the relation of concepts may be quite broken, and even go so far as to assume the dignity of full illusions. A full list and explanation of the possible causes of disturbances of the perceptive process would be beyond the scope of this article; although it is distinctly in place, I believe, to mention a few of the most common, simply to give an idea of the wide range which they occupy. Among them are diseases of the eye, such as phenomena which occur in the end distribution of the optic nerve, among which are light phenomena developed in the retina, the so-called light dust of the internal field of vision, and the shadowings and polychrome pictures. These are all aided by processes in the retinal vessels, such as those involving the blood-corpuscles; likewise the pulsations of the central artery, opacities of the cornea and vitreous, and indeed all conditions producing entoptic shadows on the retina may give rise to illusions. And these are not all; in addition we may include catarrhs of the middle ear, irritations of mucous membranes and the skin of the head and face, blows and falls upon the head, as well as morbid changes in the viscera and muscles.

The sum of the matter is this: We constantly see children who lie habitually, and usually for no recognized reason. This habit is commonly looked upon as an indication of spontaneous viciousness. In the majority of cases this opinion has no basis in fact. The children usually are suffering from disorders of mind or body, or both, which radically interfere with the transmission of conceptions and perceptions from the internal to the external processes of expression, so that they are really unable to be more exact than they seem; usually these peculiarities are either neglected or cause severe punishments to be inflicted, with the natural result that they are confirmed and added to by various unfavorable characteristics of cruelty, revenge, slyness, and actual deceit.

Lying does not necessarily mean viciousness, nor is truth to be regarded merely as a saving means of grace. On the contrary, many a child may be led to forget the lie simply by being placed in proper physical and mental environments.

result of an experiment instituted to determine the effect of rhythm on the visibility of a succession of optical signals, tried by M. Charles Henry at the Depôt des Phares, France, is to show that it is possible to increase the range through which an optical signal will carry by adjusting the succession of flashes according to a sufficiently complex nonrhythmical law.