THE EFFECT UPON EMULSIONS OF THE HYDROXY COMPOUNDS IN BEESWAX of the particles, but the particles are less uniform in shape than those in creams A or B. Photograph IV (cream G) shows a more uniform particle shape and size than cream E but the emulsion is coarser than cream A (photograph I). On examining the photographs taken when the creams were three months old, photograph V (cream A) shows little change from photograph I and indicates that cream A has retained its fine emulsion characteristics after three months. Photograph VI indicates a larger particle size when compared with photograph II and indicates a deterioration of the emulsion with time. Photograph VII was difficult to obtain as a representative picture due to continuous movement of the particles under the microscope. It will be seen that the picture shows in the upper half a coarse emulsion and in the lower half a somewhat blurred effect. Photograph VIII appears very similar to photograph IV, indicating little change in the emulsion on standing. After six months standing and allowing for the difference in intensities of the prints, cream A has changed but little, cream B has suffered further breakdown, cream E is of large particle size and cream G has not greatly changed. From the microscopical examination it is evident that creams made from acetylated beeswax are coarser and less stable than those made from untreated beeswax. The effect of adding cetyl alcohol to the acetylated beeswax cream is, initially, to produce an improved emulsion as judged by particle size. On standing, however, this particular cream changed in consistency and was no longer uniform. The effect of adding acetyl alcohol/ ethylene oxide condensate to the acetylated wax was to reduce particle size in the emulsion, and this cream remained uniform after six months standing. The particle size of this emulsion was not as small as that in cream A made from untreated beeswax. BEESWAX/LIME-WATER EMULSION To carry the investigation a stage farther, two creams of the w/o type were made to the following formulee: Cream J Cream Beeswax 4 Acetylated beeswax -- 4 Mineral oil 46 46 Lime water B.P. 25 25 Tap water 25 25 These were made by heating the beeswax or acetylated wax in the mineral oil to 40 ø C. The aqueous phase also at 40 ø C. was added to the oil phase with controlled stirring. Each emulsion was divided into two portions and one portion was placed three times through a laboratory homogeniser. 271

JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS During manufacture the emulsions differed only slightly and there was a suggestion that the emulsion based on acetylated wax was rather "stiffer" and less white. Emulsion stability as measured by centrifuging did not appear to differ in either cream, homogenised or unhomogenised. Photograph XIII shows the homogenised emulsion made from formula J and photograph XIV the homogenised emulsion made according to formula K. .:•:•".'• •!i:• "•.'•' 2•: ' • :....(.:.•:• .. !!•oE•-,'• :•'.::½-'•'• :• •:•', • :.•.,...• .•?:,,•. •:•,:---•:-... .• :.-•- ..., ß •'• --• ..5 .. -.:-. ... , .: - ::• .... . .,:....':: •. -• ½..: :: •-• . ....:..-:. :• .' . :........• ,- .-. .. . : 9. . .. ß .:. •5.**':' :' '""' ' XIII. XIV. It will be seen that there is little difference in the structure of the t•vo emulsions. EFFECT UPON VISCOSITY At an earlier stage of this work attempts had been made to study the effect of acetylation upon the viscosity of beeswax solutions. Although the results were of no real significance, one set may be worth recording. Unfor- tunately, beeswax does not produce a dear solution in mineral oil and rapidly settles on standing. Ordinary beeswax settles much more rapidly than the acetylated product. Four "solutions" were prepared as below: 1 2 3 4 Mineral oil 95.0 95-0 95-0 95-0 Beeswax 5-0 • • -- Acetylated beeswax • 5-0 5-0 5.0 Cetyl alcohol -- • 0-35 -- Cetyl alcohol/ethylene -- -- -- 0'35 oxide condensate 272