Ergopinacone and 7-dehydrocholesterol-pinacone have been prepared by two different methods, viz., the boiling method and the carbon dioxide method. The products obtained by the two methods as well as diacetates and dibenzoates derived from them have been compared. It has been indicated that the two methods yield the same products. In conclusion the author wishes to express his hearty thanks to Prof. Y. Urushibara for his kind guidance and encouragement. He acknowledges also his indebtedness to Dr. K. Yamasaki for his advice and kindness in taking absorption spectra, and to Mr. Yasohachi Yamaguchi and to Ozi Seisi Co. for generous help.
(1) Measurements of the static friction coefficients have been made to study the oiliness of liquids. The friction surfaces consisted of a silver plate and a silver piece of spherical surface. (2) The static friction coefficients of water, hydrocarbons, aliphatic alcohols, aliphatic acids and esters have been measured. (3) The static friction coefficients of these compounds excepting the acids are all comparable with the results obtained for the glass surfaces. The friction coefficients of acids diminish rapidly with the number of carbon atoms in the chain of the molecule for the silver surfaces, while they are nearly constant irrespective to the number of carbon atoms for glass surfaces.