Reference for Chullin 248:8

ואזדא רבי יוחנן לטעמיה דאמר רבי יוחנן

R'Ishmael taught it in the above passage,<span class="x" onmousemove="('comment',' That according to R. Johanan R. Ishmael holds that two separate contacts, each time of half the minimum quantity, cannot be reckoned as one contact of the whole quantity.');">⁶</span>

Jastrow