244 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS , 8-methoxypsoralen continued to receive study as means of restoring pigmentation in limited skin areas. TM , ANTIBACTERIAL ACTION ,• , In connection with the •reported tendency of nonionic surfactants to lower the efficacy of many antibacterial agents, it was observed that various phenols react with surface-active polyethers to produce an' insoluble oil which may be responsible for problems such as irregular release of anti- bacterial agents and breakag• of emulsions. TM Microelectrophoretic studies indicated that the exterior of E. coli cells is a polysaccharide, possibly an arabate. • A review of bacteriophage described the prophave as occupying a definite site on the bacterial chromosome, dividing with the nucleus, and occasionally leaving the host to form free phage particles with tadpole-like structure, the head consisting of deoxyribonucleic acid, the tail and the covering of the head of protein the tail punctures the membrance of a bacterial cell, and the DNA of the head is injected into the bacterium, to attach to the chromosome and to synthesise viral DNA fromm the bacterial nucleic acid. TM EFFECTS OF VITAMINS ON SKIN ' On a diet free of vitamin' A, mice had hair-growth cycles as long as 24 days instead of '21 'days on normal diets. •5 The methyl ether or the palmitate of vitamin A, applied in 95 per cent alcohol to the backs of plucked mice, caused irritation which was greater in regions of resting follicles than in'regions ' of follicle growth. TM Hyperkeratosis produced in animals by chlorinated naphthalene or chlorinated phenols was accompanied by low vitamin A levels in the serum.•" Capillary resistance in rabbits was decreased by. reducing their diet to « to • the normal amount administration of , vitamins B 2, B •, C. P, and K increased the capillary resistance but izitamin B • had' no effect. TM ' AGEING Among the recent books on ageing, Hormones and the Aging Process, TM edited by. Engle and Pincas, and The Biology of Senescence, TM by Comfort, may be mentioned. In old persons, milk proteins were found to have a better substitutive value than wheat proteins, reversing the situation found in younger adults. m Normal individuals showed no change in basal respira- tory rate nor in tidal volume with advanqing age, but efficiency of ventilation was reduced about 20 per cent. m In men of 65-75 years, corticotropin appears in the blood as an activable fo•m, instead of the active form found in the blood of normal young men. TM

SOME NEW KEYS TO COSMETIC CHEMISTRY--1956 245 Squalene was synthesised from synthetic and from natural nerolidol, and was utilised to the same extent as natural squalene for cholesterol synthesis by rat liver cells. TM In passing from squalene to cholesterol, the oxygen added to form the intermediate,, lanosterol, was shown • to come from molecular oxygen, not from water, and the oxidocyclase system, involved was believed to be a metalloenzyme similar to oxidases working upon various aromatic and hydroaromatic compounds. TM The last links are 'being furnished in the series of steps involved in synthesislug cholesterol from acetate, TM and the data obtained may hasten the control of ageing in arteries, connective tissues, etc. Evidence was presented indicating that a defic!ency of vitamin B 6 may influence development of atherosclerosis. m In humkn cartilage, uronic acid was found to decline with age, and hexdsamine to increase in relative concentration, up to maturity.•78 Examin- ation of individual colla'gen fibres and bundles with the phase cor•trast microscope revealed variant fibres with chemical and physical behiviour differing "from that •of collagen, with the proportion of the variant fibres apparently related to age. TM 'Observation of the greatly increased amounts of work needed to br/ng the cbllagen fibres of rats from the stretched inelaitic state to the contracted elastic state, as compared with fibres from young rats, led to the conclfision that forces between the collagen molecules change with age of animal. •8ø• A study of' cross-linking mechanism in polymers such as polyethylene has yielded some basic data which may be applicable to similar processes which possibly are involved in the changes of connect'lye tissue fibres with age. TM The conjugated lipides of connective tissue were reported to increvise with age in the rat. •ø•' In human skin succinic dehydrogenase concentration was found to be lower in older than in younger persons. •øa ANALYTICAL METHODS Improved• analytical methods have continued to make the cosmetic chenfists' work more accurate. and effective. An improved method for deterruination of h•drocarbons in cold creams is based on adsorption of other nonvolatile materials on alumina. •ø4 The mass spectrometer was found to be valuable in relating composition of paraffins to melting point and penetrability, but not to tensile strength.. •* The separation of mixtures of fatty acids by chromatographic columns has improved,-and the saturated fatty acids from C-6 to C-22 have been quantitatively separated b.y this method. • Since the use of gas-liquid partition chromatography was first reported TM in•1952, it has made possible a tremendously more effective detailed •nalysis of complex mixtures. Sebum has been shown to contain at least 31 fatty acids, *• andsthree branched four-and five-carbon acids have for the first time been shown to be compon- ents of animal depot fat. TM The method has proven extremely valuable in