A New Model for Demonstrating the Octant Rule The aetant has become an established physical method for determining the absolute configuration of many types of organic molecules. It is now included in standard undergraduate texts.' Aho, the rule and its applications are a useful aid to teaching topological aspects of chirality. However, thestudents do find diff~eultyvisualizing the three dimensional system. Herein we descrihe a rohust Persueu model of the oetant system which is ideal for both individual and classmom demonstration. This model (see photograph) is an advance on o~hersGinceit shows the comolete octant svstern. It oermits both axial and
pnwide details on request. '1)ierassi. C., "Optical Rotatory. Disuersion," McCraw-Hill, New York. 1960. . pp. 41-129.
'Wong, K.-P., J. CHEM. EDUC., 52, A9 (1975). :'Murnhv. W. S.. J. CHEM. EDUC.. 52.774 11978).
William S. Murphy University College Cork, Ireland
686 1 Journal of Chemical Edocaflon
