TtlE EXTRACTION OF FATTY MATERIALS FROM HAIR CLIPPINGS 687 Table IV Refractive index of lipid (14.5øC) !,__ Subject 1 Subject 2 Subject 3 -- , Solvent Method I Method II Method I Method II Method I Method II Ether I 1,4765 1.4758 1.4696 1,4698 1.4720 1.4715 Methylene i chloride ' 1.4822 1,1825 1,4738 1.4700 1.4808 1.4833 Ethanol I 1.4840 1.5010 1.4890 1.4800 1.4762 1.4818 Table V Viscometry values of lipid• (27øC) P ,, Subject 1 Subject 2 Subject 3 Shear rate I seG- 1 • .......... .I Method I Method II Method 5 Method II Method I Method II I Ether extracts 442 i 1.60 2.25 4.15 3.20 1.60 1.40 663 1.10 2.15 3.05 2.60 1.45 1.25 1 326 0.85 1.70 2.15 1.85 ] .20 0.90 1 990 1.00 1.30 1.$5 1.$5 1.05 0.75 3 980 0.85 1.05 1.55 1.25 1.00 0.70 5 970 , 0.80 0.95 1.20 1.10 0.90 0.70 11 940 0.70 0.85 0.95 0.95 0.85 0.60 -- __. .•- ß Ethanol extracts 442 9.20 42.30 19.30 64.40 16.50 19.30 663 11. lO 38.00 20.90 56.40 16.00 20.90 1 326 8.00 28.80 18.40 40.50 12.90 17.20 1 990 7.00 23.30 17.80 31.90 19.09 13.90 3 980 5.70 17.20 * * 8.60 ll.lO 5 970 * * * * 7.20 9.70 11 940 I * * * * 4.80 6.80 ß •Oxving to the small amounts of material extracted by methylene chloride it was not possible to carry out rheological measurements on the lipid obtained with this solvent. *Signifies that the structure was broken down under high shear rate to gi•ve a material of apparent low viscosity. From these results it may be seen immediately that the different solvents give rise to very different materials varying from an oily to a hard waxy nature, and this will be discussed in more detail later on. However, for the moment only the effects of temperature of extraction will be discussed. 1. The method of extraction appears to give fairly reproducible results

688 JOURNAL OF THE SOCIETY OF COS3IETIC CItEMISTS as can be seen by comparing the results for the replicate ether extractions for each of the three samples of hair (Table II). The rheological measure- ments of these ether extracts are also quite reproducible, particularly when one considers that the method used for measuring the viscosity (cone and plate device), is not particularly accurate for low values of viscosity, and errors of the order of 40-50 cP are possible. 2. The effect of extraction temperature may be judged by comparing the properties of the methylene chloride extracts from methods I and II with those of the ethanol extracts. In the case of the methylene chloride extracts where the extraction temperature difference between the two methods is only 5øC, the differences in amount extracted, the refractive index and the physical appearance of the lipid were almost negligible. This is in contrast to the use of ethanol when the difference in extraction temper- ature was large and when in every case extraction at the higher temperature yielded at least twice as much material as at the lower temperature. 3. The difference in high and low extraction temperatures is also shown by the substantially larger refractive indices for the high temper- ature extracts (for two out of three samples). This is shown even more markedly in the rheological properties of the extracts (Table V and Fig. 1) F,91. Rheological Properties of Ethanol Extracts - -•--subj. 1. method ]• • "11 ---C- subj.'.2, methodI -o- subj. 3.me•od[ -•- . apparent viscosity c.P. 400O 2O0O shear rate sec-1 j Figure l which show that the lipid extracted at higher temperatures is very much more viscous than that obtained at the lower temperature. This result is in