Amino acid analyses of normal wools of several breeds and geographical origins are presented as evidence of the normal variation of composition. Some samples were from lots used for detailed comparative studies of fiber properties and processing behavior. A mohair sample was found to be similar to wool in composition. White Leghorn chicken feather keratin differed from wool in yielding larger amounts of serine and proline. Feather had characteristically smaller amounts of cystine and glutamic acid. Heterogeneity of wool and feather keratins was shown by differences in amino acid composition of fractions prepared by treatment with acid, by mechanical separation, or by partial solubilization in aqueous alcohol. Feather differs from wool in having readily separable fractions differing greatly in content of histidine, lysine, and methionine. These fractions also differ appreciably in their content of several other amino acids.

With rhodamine‐B used as an indicator, the relative acidities of selected phenols and alcohols as model hydrogen donors have been determined in toluene solution. The method involves measurement of the change from colorless rhodamine to the colored zwitterionic form produced by the hydrogen donor compound. The method has been applied to the determination of equilibrium constants for the interaction of phenol with dimethyl formamide, benzyl acetate and dioxane; the measured constants are in accord with those obtained for the same pairs by Flett (J. Soc. Dyers Colourists, 68, 59–64 (1952)), who employed infrared analysis. Consideration is given to partition of the dye between toluene and water, as influenced by hydrogen bonding and by nonelectrostatic interactions. Forces of interaction which tend to bind the dye in one phase decrease its activity in that phase and consequently reduce its tendency to move from this phase to the other. With incorporation of propiolactone polymer into the wool fiber, the activity of the dye in the fiber is reduced in relation to nonpolar as well as to aqueous solutions, and the modified wool exhibits greatly improved dyeing properties. The dye is useful also for the determination of critical micellar concentration of fatty acid soaps in aqueous solution. It also shows markedly increased binding by heat‐denatured as compared with native egg albumin, and by acetylated, as compared with normal, wool.

IN A study of the natural causes of nonscourable discoloration of wool, the question of the presence of urocanic acid in suint was raised.Neither the action of alkali as discussed by Serra and de Matco [12] nor of bacterial pigments studied by Seddon [11] and by Fraser and Mulcock [5] will account for the experimentally induced discoloration when wool is held in the presence of suint at 55° C. and at high humidities; the color is due to neither alkali nor bacterial pigments. As it is nonscourable, it is not caused by lanaurin, the deeply colored suint component discussed by Rimington and Stewart EIOI. It was thought possible that urocanic acid, which has been shown byZenisek and Kral E18] to be present in human perspiration, might also be present in suint and might, either directly or through interaction with other suint components, cause or contribute significantly to this experimental wool discoloration and be involved in natural wool discoloration. Urocanic acid alone on wool when held at 55° C. at high humidities causes discoloration, though less than that caused by suint under the same conditions. However, the concentration of urocanic 1 A laboratory