10 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS as is shown by the contours lying at an angle to the concentration and temperature axes and across more than one critical peak temperature. In view of what is known of the constituents of lanolin this is exactly what would be expected. Again there is evidence of the formation of peroxides. Some traces of the carrier peak remain, but it is more broken up than in the case of the olive oil pointing to higher concentrations or high surface activity of some of the polar compounds, or possibly both. The two large peaks at low concentration between 18 and 19øC are due to free acid, probably produced by hydrolysis during the extraction and purification of the lanolin, and can be almost exactly reproduced by using a pure mineral oil to which a small quantity of lauric acid has been added. The sloping contours at 19 to 19.5øC suggest ketonic or hydroxy-acids. The above sample of lanolin was degraded by heating a thin layer in an oven at 100øC for 100 hours. The resulting diagram (Fig. 4) is much simplified, and suggests that a certain amount of re-esterification has taken place. There is an increased and more definite indication of ketones (two peaks at 16.4øC) whilst the peroxide, hydroxyl and carrier peaks have largely disappeared. There are, however, still strong indications of acid constituents between 18 and 19øC, but at a lower concentration than in Fig. $ since the peaks appear at a higher lanolin concentration. / •.// / // ! / I II I I I ! /! / III I ß ,, ,,' 15 Lanolin, stored 10 years. Index contours 40 (outer) x 5 øC

BAND SHAPE ON DYED PAPER AS A METHOD OF CHROMATOGRAPHY 1,1 The main change appears to be oxidation of secondary hydroxyl to ketonic groups as might be expected. Fig. 5 was obtained by using a sample of lanolin which had been in store for ten years. Here re-esterification has definitely taken place. The acid and hydroxyl peaks are markedly less in evidence, but no ketone has been produced. There is a small amount of peroxide showing at the top, left-hand corner of the diagram. The reappearance of peaks in the 17.8 to 18øC range suggests the reforming of the carrier peak, a phenomenon to be expected if the concentration of the polar groups had been very consider- ably reduced. CONCLUSION Outline/area index chromatography appears to be a useful and sensitive technique for the examination of mixtures the nature and complexity of which make other methods difficult to apply. At this stage it is presented as a potentially useful idea rather than as a completely developed method. There are still a number of points, particu- larly those associated with the influence of molecular structure, which are not clear, and, at the moment, no satisfactory theoretical explanation of the variation of the index can be put forward. The obvious disadvantage is the amount of work involved in the production of the diagrams, but against this must be set the simplicity of the apparatus and technique, and the rapidity with which the results may be obtained. While it is not suggested that the method would be used where other established techniques are satisfactory, except perhaps as a method of preliminary examination, it is of interest that an infra-red examination of the sample of lanolin did not yield anything like as much detailed information as the outline/area index diagrams. ACKNOW•.EDGE•ENTS The author wishes to thank Dr. G. F. Reynolds, Reader in Analytical Chemistry, and the Esso Petroleum Co. for the sample of mineral oil, and Dr. A. G. Briggs for advice and assistance with the I.R. examination of the lanolin. (Received ß 2nd September 1964) REFERENCES (1•) Rutter, L. Nature 161 435 (1948). (2) Poxon, D. W. J. Oil Colour Chemists Assoc. 41 291 (1958). (•l) Poxon, D. W. J. Oil Colour Chemists Assoc. 43 245 (1960). (4) Poxon, D. W., Agger, R. T., Beaumont, D. E. and Pugh, J. A. J. Oil Colour Chemists Assoc. 46 339 (1963). 3