_Sudden Blanching of the Hair from Violent Emotions_.--The color of the hair depends mainly upon the presence of pigment granules, which range in tint from a light yellow to an intense black. A recent investigator has succeeded in extracting the coloring matter of the hair, and has found that all the different shades are produced by the mixture of three primary colors--red, yellow, and black. "In the pure golden yellow hair there is only the yellow pigment; in red hair the red pigment is mixed with more or less yellow, producing the various shades of red and orange; in dark hair the black is always mixed with yellow and red, but the latter are overpowered by the black; and it seems that even the blackest hair, such as that of the negro, contains as much red pigment as the very reddest hair." Hence, "if in the negro the black pigment had not been developed, the hair of all negroes would be a fiery red."--DR. C. H. LEONARD. _The Hair: Its Diseases and Treatment_. The gradual disappearance of this pigment causes the gray or white hair of old age. This natural change in color does not necessarily denote loss of vitality in the hair, as it often continues to grow as vigorously as before it began to whiten. Cases of sudden blanching of the hair from extreme grief or terror are often quoted,--those of Sir Thomas More and of Marie Antoinette being well-known instances in point. An interesting circumstance has been discovered with regard to such cases, namely, that the change of color is not dependent upon the disappearance of the pigment of the hair, which always takes place slowly, but upon the sudden development in its interior of a number of air bubbles, that hide and destroy the effect of the pigment, which itself remains unaltered. Dr. Landois mentions the case of a German printer whom he attended, at a hospital, in the summer of 1865. This man had long been intemperate in his habits, in consequence of which he was seized with delirium tremens. The delirium, as is usual in such cases, was of an extremely terrifying nature, and lasted four days. On the evening of the fourth day the hair was unaltered, but on the morning of the fifth the delirium had disappeared, and his hair, which previously was fair, had become gray. It was examined with the microscope, when it was found that the pigment was still present, but that the central streak of each was filled with air bubbles. How this superabundance of air finds its way into the hair in these cases of sudden blanching, physiologists have not yet been able satisfactorily to explain.--In this connection, however, it may be observed that air bubbles exist, more or less, in all hair, mingled with the pigment granules.