Professor Hefferlin [stamped, APR 14 1986] You can easily calculate the number of hydrogens with the formula. nH equals (2 plus 2nC plus nN) minus 2U nC, nN and U are given in the tables. nO does not affect nH. All this follows from valence rules. In saturated molecules, adding "C" is equivalent to adding [diagram]; N to [diagram]. I doubt if the original printouts are extant. JL X . . . 4/14/86 (["delta" symbol] if R. Platt) et al.