THE DERMATOLOGIST LOOKS AT THE HAIR PROBLEM 137 The quantities'of basic amino acids isolated agree essentially with those reported in the literature. Methio- nine has been found in human hair, and its amount determined as 1.0%. Per Cent Arginine ..................... 10.7 Histidine ..................... 0.63 Lysine ....................... 2.40 Cysteine ..................... 13.7 Tyrosine ..................... 2.1 Glutamic acid ................ 10.6 Aspattic acid ................. 3.5 Methionine ................... 1.0 Enkeratins, e.g., wool and hair, are distinguished from pseudokeratins according to Clay, et al. (12), in that their basic amino acids (histidine, lysine, and arginine) are found in a relatively constant molecular ratio of 1:4: 12. The cystine and cysteine (both non-basic amino acids), nitro- gen and sulfur content of 120 sam- ples of human hair was determined. The relation of age, sex, and pig- menration to the composition of hair was studied. No consistent rela- tion between age and composition was found. There was more cystine and cysteine in male hair than in fe- male hair. Dark hair contained more cystine than did light hair. These differences were statistically signifi- cant. No significant variations in the nitrogen and sulfur content were observed. Hair contains larger amounts of lead and in cases of ab- normal exposure 'it may retain as much as 508 mg. per kilo. Bagchi, et al. (13), reported that black hair of women gives the largest amount while gray hair of men and women gives the minimum, and brown or golden brown or other shades oc- cupy an intermediate position. Lead may be a likely factor in producing the characteristic pigments of hair in different nationalities. Relatively large quantities of lead 'were found in the urine and feces of some Hindu men and women and, since correspondingly high quantities were then found in the hair, it is considered that lead is absorbed into the general circulation and eliminated through the hair. In many instances a mild form of alopecia was associated with high lead content in the hair, and it is suggested that chronic lead intoxi- cation may prevent access of nour- ishment to the follicles, with the re- sult that the hair falls out. According to Butcher when skin producing black hair is inter- changed with skin producing white hair in the piebald rat, white hair frequently grows on the skin which for.rnerly had black hair. Likewise if skin producing black hair is in- cised and sutured back in place, it often produces white hair. The present conception of pig- ment fiormation seems to be that pigment results from the combina- tion of a chemical substance, or propigment, carried by the blood with an enzyme in the cells of the hair bulb. In these rats the pro- pigment was present, since the rest of the hair of the animal remained black and black hairs often peared among the white ones on the grafts. The white hair was not due to the lack of innervation, as was shown by denervating areas. The enzymatic potentialities of the cells

138 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS of the hair bed must, therefore have been affected by the lack o.f vascu- larity and nutrition immediately following the operation, since injec- tion studies show that the vascular supply of the graft soon becomes similar to the supply of the sur- rounding area. Once the pigment-forming ability is lost by the cells, there is no resti- rutire capacity to respond to the application of irritants to the skin. Application of irritants to the skin has failed to induce the cells of the hair beds to form pigment again. Growth or production of the hair by the hair bed is also affected by vascularization. Increased blood supply accelerates hair growth. Growth is not affected permanently by poor blood supply, as shown in these experiments, while the pig- ment-forming capacities of the cells are affected permanently. When the skin was incised, all blood supply was eliminated. Nu- trition was supplied to the graft by tissue fluid from below the graft and from around its periphery. This tissue fluid sufficed to supply the cells of the hair bulb with nutri- tion necessary for the survival of their growth potentialities. The tissue fluid, however, did not pro- vide the cells with the substances necessary for the survival of their enzymatic potentialities. Thus, the requirements for growth are less than for pigment formation. SUMMARY AND CONCLUSIONS I have attempted to touch briefly on all of the fundamental points that are of' vital interest and im- portance particularly concerning scalp hair. It was my intention to draw your attention to our woe- ful lack of fundamental information on matters of daily concern to all of us. I trust that I may have suc- ceeded in enlisting your co-operation in attempting to solve: (1) What basic factors are in- volved in keeping alive the vital hair papilla and follicle ? (2) Do only internal mechanisms control the life span of the papilla and follicle or can they be influ- enced by local measures of any type, such as tonics, stimulants, massage, hyperemia, etc.? (3) If local treatment is of value, what form is best, a liquid or an ointment, and what type base whether liquid or ointment, is most acceptable to the scalp and hair? (4) What controls hair pigment? (5) By further study of hair shape, composition, etc., could not some better and perhaps safer methods for curling or straightening the hair be found? (6) What is dandruff and what role does it play in the causation of premature alopecia--if any ? BIBLIOGRAPHY 1. Danforth, C. H., "Hair with Special Reference to Hypertrichoris," Mono- graph A.M.A. (1925). 2. Unna, quoted from McCarthy, L., "Diagnosis and Treatment of Diseases of the Hair," C. V. Mosby Co., St. Louis (1940). 3. Barabal, H. S., and Freeman, N., "Sud- den Graying of Hair, Alopecia and Diabetes Mellitus of Psychogenic Ori- gin," Psychiat. St., 20, 31-38 (Jan., 1946). 4. Hamilton, J. B., "Relationship Between Common Baldness and Male Sex Hor-