1-4.Skin and pH
	ｐＨ value ●It is a pH value from which it is divided into 0-14 to have made whether the material is acidity or alkalinity a concrete numerical value. Seven shows that alkalinity strengthens by strengthening of acidity by becoming small of the numerical value at the center, and growing of the figure. ※ｐＨの意味 ●The pH of the skin is not a pH value of the skin and generally directs the pH of the sebum membrane. The sebum membrane shows acidulous of 6.5 from pH4.5 because of the lactic acid and the amino acid contained in the fatty acid and the sweat contained in the sebum. ●Though there is an individual variation by Hadashiti and the environment Oily skin（Acne・Sebrrhoticus dermatitis） Dirt of skin→It inclines at acidity. Dry skin（Atopy・Aging） After it sweats/After using the alkali washing→It inclines at alkalinity.
	Alkalinity ●Stratum corneum is made of the protein named keratin. There is a characteristic of weakness to the alkali though the protein is strong in the acid. Therefore, corneum cell melts gradually and the surface of the skin enters the state that gets rough if the alkali material touches for a long time. It becomes hypersensitive, and then, because the resistance power of the skin falls, it is causing and as for eczema and poisoning. Restoration power ●There is working returned to acidulous of the former even if the surface temporarily inclines at alkalinity in a healthy skin. This is called an alkali neutralizing ability. The amount of the secretion of the sebum decreases, and however, the solve alkali neutralizing ability doesn't work, and the resistance power becomes weak by aging kitchen work during the state to always touch , for instance, for a long time etc. the decline of the alkali material. Acidity ●The dirt of the skins such as the sebum and dust oxidizes when time passes, and changes into the resin of lipid peroxide. It becomes the cause of Cabre, dermatitis, and eczema when adhering for a long time because the lipid peroxide is a stimulus.