THE EXTRACTION OF FATTY MATERIALS FROM HAIR CLIPPINGS (•89 accord with the physical appearance of the lipid the material extracted at the higher temperature is found to be much harder. The effect of ethanol extraction In view of the large differences found between extraction with ethanol at low and high te•nperatures, a further experiment was carried out with a sample of hair which was sequentially extracted as follows:- (a) 25 cycles ethanol at 32-35øC (b) 25 cycles ethanol at 45-50øC (c) 25 cycles ethanol at 56-62øC (d) 25 cycles ethanol at 68-78øC A fresh sample of ethanol xvas used for each extraction. The results are shown in Table VI and Fig. 2, in which it can be seen that the quantity of material obtained was found to increase linearly with temperature. The differences in the physical appearance of the various samples of The Effect of Temperature on Ethanol Extractable Material. extract mean extraction temp.'• Figure 2 extracted lipid are also shown in Table VI, and these clearly show the transition from a waxy to powdery material. Although considerably more matehal is being removed from hair at higher temperatures using ethanol, it is obvious that this material bears no

690 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table VI Quantity of hair lipid obtained by ethanol extraction Temperature of extraction 32-35øC 45-50øC 56-62øC 68-78øC Quantity of material obtained S.0% 0.8% 1.a% 1.1% Cumulative quantity S.0% s.s% 7.1% S.2% Appearance of extracted material oil/wax powder/wax white powder and little wax white powder relation to the material normally recognized as hair lipid. There are a number of possible explanations to account for this result: (a) The product obtained is a result of hair degradation. (b) The product obtained is sebum which has been polymerized or other- wise modified on the hair surface over a long period of time so that it is strongly bound to the hair, and is only removed at high temperatures. (c) The hair lipid is considerably modified during the extraction procedure at higher temperatures. Of these possibilities (c) can be eliminated since samples of hair lipid which have been obtained by low temperature extraction show no great change when heated in ethanol to much higher temperatures. From the present work it is not possible to say whether (a) or (b) is more likely although Ireon and Holmes (14) have shown that prolonged extraction of hair with alcohol at high temperatures removes intracellular material. It is still possible, however, that polymerized or modified hair lipid derived by process (b) could account for part of the extra material obtained at high temperatures. A sample of hair which had been extracted with ethanol at 32-35øC was examined under an electron microscope and it was not possible to detect any hair damage. In contrast, it is possible to detect hair damage in samples of hair which have been extracted with ethanol at high temperatures for long periods (13). This result supports hypothesis (a) above although it does not preclude the possibility of process (b) also taking place. However, the ex- traction of materials from the internal structure of hair by ethanol under mild conditions, without damage to the surface, must still be considered a possibility although the amounts obtained will probably be negligibly small.