AD HOC ('Association for the Discussion of the History of Chemistry') started life in London in 2004 as a monthly reading group, organised by Hasok Chang. From the autumn of 2010 we are expanding the basis of the group to Cambridge, to hold parallel series of meetings at UCL and Cambridge while encouraging cross-traffic. For travel bursaries and other expenses we are grateful to have support from the Society for the History of Alchemy and Chemistry (SHAC). While our main focus is on history, we also pay attention to philosophical, sociological, public and educational dimensions of chemistry. Over the past years our meetings have been attended by a variety of scholars, ranging from advanced undergraduates to teaching staff in both science studies and chemistry, and often attracting visitors from other parts of the UK and abroad. With the expanded geographical basis we hope to stimulate a higher volume and broader range of activities, while maintaining the group's informal and friendly ethos.