384 QUARTERLY REVIEWS Triterpenes tetracyclic 9 328 Tropolones 5 99 Tryptophan biological degradation of 5 227 Ultrasonic analysis of molecular relaxation processes in liquids 11 134 Ultrasonic waves effects of on electrolytes and electrolytic pro- cesses 7 84 Veratrum alkaloids 12 34 Wool wax constitution of 5 390 A'-Ray crystal analysis modern methods of determination of mole- cular structure by and their ac- curacy 7 335 p-Xylylene chemistry of and of its analogues and polymers 12 301 384 QUARTERLY REVIEWS Triterpenes tetracyclic 9 328 Tropolones 5 99 Tryptophan biological degradation of 5 227 Ultrasonic analysis of molecular relaxation processes in liquids 11 134 Ultrasonic waves effects of on electrolytes and electrolytic pro- cesses 7 84 Veratrum alkaloids 12 34 Wool wax constitution of 5 390 A'-Ray crystal analysis modern methods of determination of mole- cular structure by and their ac- curacy 7 335 p-Xylylene chemistry of and of its analogues and polymers 12 301 QUARTERLY REVIEWS QUARTERLY REVIEWS contains articles by recognised authorities on selected topics from general physical inorganic and organic chemistry.The Journal and Annual Reports interest primarily the research worker Quarterly Reviews is designed for a wider range of readers. It is intended that each review article shall be of interest to chemists generally and not only to workers in the particular field being reviewed. The submission of reviews for publication is welcomed but intending authors are advised to write in the first place to the Editor The Chemical Society Burlington House Piccadilly London W.1. Such preliminary communications should be accompanied by an outline of the ground to be covered rather than by the completed manuscript. QUARTERLY REVIEWS QUARTERLY REVIEWS contains articles by recognised authorities on selected topics from general physical inorganic and organic chemistry. The Journal and Annual Reports interest primarily the research worker Quarterly Reviews is designed for a wider range of readers. It is intended that each review article shall be of interest to chemists generally and not only to workers in the particular field being reviewed. The submission of reviews for publication is welcomed but intending authors are advised to write in the first place to the Editor The Chemical Society Burlington House Piccadilly London W. 1. Such preliminary communications should be accompanied by an outline of the ground to be covered rather than by the completed manuscript.