COSMETIC PROTEIN HYDROLYSATES 453 the column with the low molecular weight material. When preparing the molecular weight distribution curve of the enzyme hydrolysate, the absorbance due to the pre- servative had to be subtracted. Figure 2 is the calibration curve, and shows the relationship of molecular weight to elu- tion volume. The elution volume is expressed as Kav, which is the relationship of the elution volume to the void volume and the total bed volume. Kav= Ve - Vo Ve - Vo As can be seen from the calibration curve, the elution volume has a straight line rela- tionship to the logarithm of the molecular weight over most of the range between the void volume and the total bed volume. From the elution diagrams and the calibration curve, molecular weight distribution curves were drawn. These graphs are shown in Fig. 3. These distribution curves are used to calculate both the weight average and the number average molecular weights. The weight average and the number average molecular weights were calculated as follows. Pi (Pi/Mi) where Mw = weight average molecular weight P = per cent of material at a constant elution volume interval Mi = molecular weight at this interval Mn = P•/(P•/M•) Mn = number average molecular weight P• = percentage of material at a constant elution volume interval M• = molecular weight at this interval In Table I the molecular weight averages calculated from the molecular weight dis- tribution curves are shown. ULTRACENTRIFUGATION In Table II, the results of the ultracentrifuge run are compared to the gel filtration results. Table I Protein Hydrolysate Weight Average Number Average Enzyme 4,000 + 10 per cent 2,100 + 10 per cent Acid 9,300 +'10 per cent 2,500 - 10 per cent Steam 7,800 - 10 per cent 1,800 - 10 per cent

454 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Molecular Weight Ultracentrifugation versus Gel Filtration a Gel Filtration Ultracentrifugation Over 5,000 8,700 - 3,600 5,000 - 1,000 3,000 - 1,500 aThe molecular weights measured by these 2 methods correlate closely. Table III Fraction Hair Type Protein Substantivity mg Protein/100 g Hair Greater than 30,000 Bleached 140 Bleached-waved 300 30,000-5,000 Bleached 50 Bleached-waved 290 5,000-1,000 Bleached 80 Bleached-waved 370 Less than 1,000 Bleached 200 Bleached-waved 510 Hydroxyproline Bleached 40 Bleached-waved 100 600. 500. ,,.. o•400' E ._ '2 300 200- 100- mmmmmmmmm_ Dieached. W= .... .mmmmmmmmmmmmmmmmmmmmm-- mmmmmmmmmmmm •mmmmmmmmmmm.mm Bleached Hair mmmmmmmmmmmmm•mmmmmmmmmmmmmmm Molecular Weight XlO 3 Figure 4. Substantivity of various molecular weight fractions