Abstract: A correction curve (FIG. 19) is prepared by plotting 12CO2 concentrations and 13CO2/12CO2 concentration ratios which are determined on the basis of a calibration curve and 13CO2 and 12CO2 absorbances of gaseous samples having the same 13CO2/12CO2 concentration ratio but known different 12CO2 concentrations. A gaseous test sample containing 13CO2 and 12CO2 as component gases is introduced into a cell, and spectrometrically measured. A 12CO2 concentration of the gaseous test sample is determined by way of the spectrometric measurement. A concentration ratio correction value is obtained on the basis of the correction curve and the 12CO2 concentration of the gaseous test sample thus determined. A measured 13CO2/12CO2 concentration ratio is divided by the concentration ratio correction value thus obtained for correction of the 13CO2/12CO2 concentration ratio. Thus, the measurement accuracy of the concentration ratios of the component gases can be improved.

Abstract: Cosmetic or dermatological compositions comprising in a cosmetically acceptable medium (A) at least one film-forming oligomer having a molecular weight, measured by steric exclusion chromatography, of less than or equal to 50,000, said at least one film-forming oligomer being soluble or dispersible in said cosmetically acceptable aqueous medium; and (B) rigid, non-film-forming particles of average size less than or equal to 1 .mu.m, said rigid, non-film-forming particles being dispersed in said cosmetically acceptable aqueous medium, wherein the compositions may be used, for example, as product bases for maintaining the hairstyle, as products for coating the eyelashes and the eyebrows or as nail make-up and/or care products.