came still further blanched. He resolved never to go to sea again, and kept his resolution."A lady, travelling in France subsequently to the Franco-Prussian War, heard of a considerable number of cases of hair blanching (more or less marked) in consequence of fright."
Dr. Laycock, in speaking of pigmentation of the hair, asks whether grayness and baldness are due to loss of tone of the hair-bulbs solely, or are ultimately associated with trophic nervous debility of certain unknown nerve-centres. He points out that the regional sympathy which characterizes trophesies is well marked, and that, as regards baldness, it extends from two points, the forehead and the vertex, ending at a line which, "carried round the head, would touch the occipital ridge posteriorly, and the eyebrows anteriorly." So with the beard, etc. In connection with a succeeding remark, that the eyebrows are a clinical region in brow-ague, herpes, and leprosy, the case already referred to, of a woman who suffered in the night from a severe attack of tic, and found in the morning that the inner half of one eyebrow and the corresponding portion of the eyelashes were perfectly white, may be mentioned. Laycock points out the fact that the hair over the lower jaw is almost always gray earlier than that over the upper jaw, and that tufts on the chin generally turn white first.—(Op. cit., May 13.)
- Every hair of the head was colored alternately brown and white from end to end. The white segments were about half the length of the brown, the two together measuring about one-third of a line. Mr. Wilson suggested the possibility of the brown portion representing the day-growth of the hair, and the white portion the night-growth, and this opinion was corroborated by the remarks of Dr. Sharpey and others of the Fellows who took part in the discussion. Under the microscope, the colors of the hair were reversed, the brown became light and transparent, the white opaque and dark ; and it was further obvious that the opacity of the white portion was due to a vast accumulation of air-globules, packed closely together in the fibrous structure of the hair, as well as in the medulla. There was no absence of pigment, but the accumulation of air-globules veiled the normal color and structure. Mr. Wilson observed that, as the alteration in structure which gave rise to the altered color evidently arose in a very short period, probably less than a day, the occurrence of a similar change throughout the entire length of the shaft would explain those remarkable instances, of which so many are on record, of sudden blanching of the hair; and he ventured to suggest that, during the prevalence of a violent nervous shock, the normal fluids of the hair might be drawn inward toward the body, in unison with the generally contracted and collapsed state of the surface, and that the vacuities left by this process of exhaustion might be suddenly filled with atmospheric air.—Lancet, April 20, 1867.