THE STUDY OF SURFACE ANOMALIES OF FATTY SUBSTANCES 737 were fabricated without melting by means of a suppository press (Mabille type•'). These suppositories were softer. Dilatometry at constant tem- perature of 25øC yielded a relative reduction of volume of 0.2%, i.e., practically nil. After 27 days no surface defects appeared. All of these results were predictable because the fatty substance had been ground by the press, and the crystals had been oriented in relation to each other. (f) The cocoa butter-carbon black mixture was tempered, then cau- tiously melted in the thermostat without exceeding 36øC, and finally poured into a mold. The suppositories so prepared were then placed in a thermostat at 25øC. After the first hour, the surface of the suppository becomes dull, but no circinate forms appear. The dullness originates from Figure IT--Shrivelled surface of supposi- tory containing large quantities of S-form nuclei (12X). the presence of thousands of fine excrescences, due probably to the many •-form nuclei not entirely destroyed at 36øC. After one hour some wrinkles appear on the dull surface. After six days (Fig. 17), these defects are en- tirely analogous to those found when an apple shrivels. (g) The glass rod technique (cf. c above) was applied to the cocoa butter-carbon black mixture tempered at 25øC and then melted at 36øC. After six days at 25øC the surface is dull, but no wrinkles are formed be- cause the volume of the glass is constant. The wrinkles described in (f) above are therefore due to shrinkage throughout the mass of the sup- pository. In summary, the foregoing experiments make it almost certain that two major phenomena are related to "bloom": Manufactured by Instrument de Precision, 4 rue Rampon, Paris, France.

738 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 1. Formation of crystals starting from a crystalline nucleus and de- veloping in rings. This is a rather frequent phenomenon in crys- tallization. 2. Spadally nonhomogeneous reduction of volume producing wrinkles. (h) An entirely different problem, that of liquid fatty exudates, is presented below: For this study, suppositories were prepared from the following mixture: Transester Suppocire C--Polyglycol (M2130)* ................. 50 g. Glycerol monostearate (Geleol) .............................. 10 g. Propyleneglycol monostearate (Monosteol) ..................... 40 g. Printex U carbon black* ..................................... $ g. ø11" Figure 18.--Dilatometric curve (augmentation du vol. = Increase in volume heures = hours). Figure 19.---Liquid exudate (12X). Figure 20.---Solidified exudate (12X). The melting point of this mixture (U-tube method) is 36.6øC, and its expansion curve at 28øC is shown in Fig. 18. An increase in volume of ap- proximately 0.35% is observed. Observation of samples stored in hermeti- cally sealed flasks reveals no change after 5 hours after 5• hours, some liquid exudates appear on the surface of the suppository after 21 hours, the exuded liquid accumulates in transparent droplets (Fig. 19). However, *Cf. Appendix I.