290 JOURNAL OF THE SOCIETY O17 COSMETIC CHEMISTS person is used as the subject for the two compounds being compared. Thus, it is more time-consuming as it requires the technician, equipped with sterile rubber gloves, to wash each hand of the subject individu- ally. As advantages, however, by using the same skin for the two materials, it tends to eliminate what might be an error due to two individuals possessing different types of skin which would react in a different manner to the two materials being compared and to the degerming process. The re- mainder of the test as to plating of the wash water for bacterial counts, interpreting the data, etc., remains the same. S LrMMA RY An in vivo method for determining the skin-degerming efficacy of the product hexachlorophene when in- corporated in soap has been pre- sented here in detail, together with a brief discussion of some of its variables and reasons for certain phases of the technique. BIBLIOGRAPHY (1) Price, P. B., "New Studies in Surgical Bacteriology and Surgical Technique with Special Reference to Disinfection of Skin," •t../lm. Meal../lssoc., 111, 1993- 1996 (1938). Price, P. B., "The Bacteriology of Nor- mal Skin a New Quantitative Test Applied to a Study of the Bacterial Flora and the Disinfectant Action of Mechanical Cleansing," y. Infect. Dis., 63, 301-318 (1938). (2) Traub, E. F., Newhall, C. A., and Fuller, R. J., "Studies on the Value of a New Compound Used in Soap to Reduce the Bacterial Flora of the Human Skin," Surg. Gynecol. Obstet., 79, 205-216 (1944). (3) Unpublished data, personal communica- tion. SPECTROPHOTOMETRY IN THE ANALYSIS OF COS- METIC PRODUCTS* By G. ROB•.RT CLARK Chief, Division of Cosmetics, Food and Drug •ldministration, Federal Security •lgency, tl7ashington, D.C. THE PAST ten or twelve ' years have seen a rapid growth in the industries producing instru- ments for scientific investigation. A considerable portion of the ex- pansion has been in production of spectrophotometric devices. Ac- * Presented at the May 18, 1951, Meeting, New York City. curate automatic recording spectro- photometers have been produced as standard items, some of these are, or were until recently, available from stock. The literature describing appli- cations of these instruments has been increasing at a tremendous rate. It appears that another dec- ade or so will see the spectro-

290 JOURNAL OF THE SOCIETY O17 COSMETIC CHEMISTS person is used as the subject for the two compounds being compared. Thus, it is more time-consuming as it requires the technician, equipped with sterile rubber gloves, to wash each hand of the subject individu- ally. As advantages, however, by using the same skin for the two materials, it tends to eliminate what might be an error due to two individuals possessing different types of skin which would react in a different manner to the two materials being compared and to the degerming process. The re- mainder of the test as to plating of the wash water for bacterial counts, interpreting the data, etc., remains the same. S LrMMA RY An in vivo method for determining the skin-degerming efficacy of the product hexachlorophene when in- corporated in soap has been pre- sented here in detail, together with a brief discussion of some of its variables and reasons for certain phases of the technique. BIBLIOGRAPHY (1) Price, P. B., "New Studies in Surgical Bacteriology and Surgical Technique with Special Reference to Disinfection of Skin," •t../lm. Meal../lssoc., 111, 1993- 1996 (1938). Price, P. B., "The Bacteriology of Nor- mal Skin a New Quantitative Test Applied to a Study of the Bacterial Flora and the Disinfectant Action of Mechanical Cleansing," y. Infect. Dis., 63, 301-318 (1938). (2) Traub, E. F., Newhall, C. A., and Fuller, R. J., "Studies on the Value of a New Compound Used in Soap to Reduce the Bacterial Flora of the Human Skin," Surg. Gynecol. Obstet., 79, 205-216 (1944). (3) Unpublished data, personal communica- tion. SPECTROPHOTOMETRY IN THE ANALYSIS OF COS- METIC PRODUCTS* By G. ROB•.RT CLARK Chief, Division of Cosmetics, Food and Drug •ldministration, Federal Security •lgency, tl7ashington, D.C. THE PAST ten or twelve ' years have seen a rapid growth in the industries producing instru- ments for scientific investigation. A considerable portion of the ex- pansion has been in production of spectrophotometric devices. Ac- * Presented at the May 18, 1951, Meeting, New York City. curate automatic recording spectro- photometers have been produced as standard items, some of these are, or were until recently, available from stock. The literature describing appli- cations of these instruments has been increasing at a tremendous rate. It appears that another dec- ade or so will see the spectro-