[en] The relationship between the path and energy of ions with 3≤Z≤10 in Ilford C2 nuclear emulsions is studied. It determined the average state of charge of ions in each velocity intervals. Results are given in a table for ₂He, ₃Li, ₄Be, ₅B, ₆C, ₇N, ₈O and ₁₀Ne. For each velocity interval, it is possible to apply the Blackett relation which links, for the same velocity, the path ΔR of a particle with M (mass) and Z (charge) to the path ΔR' of a particle with M' and Z'. Results are given in tables and graphics representing the particles energy with the particles path. (M.P.)