We are grateful to the many people who have contributed to our understanding of both the chemistry and the nature of TMC-1. In particular;
we thank N. G. Adams;
D;
Smith;
W;
M;
Irvine;
F;
P;
Schloerb;
N. W. Broten and J. M. MacLeod for several helpful discussions and preprints and E. Herbst;
E;
Churchwell;
H;
Matthews;
D. K. Bohme and G. F. Mitchell for sending material in advance of publication. TJM is supported by a SERC Advanced Fellowship;