20 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS obtained for the soap-type creams. The actual per cent weight losses for the creams containing no humectant were approximately the same as the soap-type creams at 30% and 70% R.H., however, at 50% R.H. the value for the soap-type cream was considerably lower than that ob- WE,G.T LOSS Or SOA. TY.E C.E^M ^T .......... GLYCERIN . • '-- • • --_ •"• •:•- ............. HOURS 24 HOURS 4E HOURS WEIOHT •055 OF NON-IONIC TYPE GRE• • $0% RELATIVE HUMIDITY I _ I x SORBITOL o GLYCERIN •#o•s • •o•s • •o• o o P_ 5 IO 15 20 o 2 5 IO 15 P_o Figure 10 0 2 5 I0 15 20 WEIGHT LOSS OF SOAP TYPE CREAM AT 50%. RELATIVE HUMIDITY SOR811'OL • - •. -- ......... GLYCERIN // '•-'" , ""'"'"• I0- _ -PROPYLENE GLYCOL f/ 5 WEIGHT LOSS OF NON-IONIC TYPE CREAM AT 50% RELATIVE HUMIDITY X SORBITOL o GLYCERIN I0 • ß PROPYLENE GLYCOL _ C 8 •OURS •4 •OURS 48 •OURS o • •, •o •5 •o 0 • • •0 •5 •0 0 z • •0 •5 •o Figure 11

HYGROSCOPIC AGENTS AND THEIR USE IN COSMETICS 21 rained f'or the non-ionic cream. mectant, propylene glycol was the On storage at 300-/0 R.H., all of the most effective with sorbitol next humectants were effective in in- and glycerin last. This was also hiblting weight loss. At 2% hu- true at 5% and 10% humectant WEIGItT LOSS OF SOAP TYPE CREAM AT 70% RELATIVE HUMIDITY SORBITOL ........ GLYGERIN I ----•---PROPYLENE GLYCOL /' HOURS • 2• HOURS •8 HOURS t •[lOST L055 OF •O•-IO•lO TY•[ GR[• •T 70• R[L•TIV[ 8•l•lT• ..... XISORBi •OL o •LYCERIN HOURS - • • • • •• • • HOURS • HOURS 20 •5 I0 15 I0 o t 5 •o •5 to o t 5 IO HUMoeCTAIVT V/oe1GHT % Figure 12 I I WEIGHT LOSS'OF sOAP TYPE •REAM AT I-½-A •--- I--I-, '--•' ." T• ......... a, rCER• ' ..• RELATIVE HUMlaITY J •L•TIV•I, TY WEIGHT LOSS OF NON -IONIO TYPE OREAM AT 5 % HUME•TANT ,Y .-- -'- ,W •- /' .-.-• - /. '?' - _ // -t- . '• .---" - _ 4 6 5 4 0 4 8 12 16 24 :56 48 0 4 8 12 16 24 :56 TIM•'-HDURS Figure 13