Webster's Revised Unabridged Dictionary · 1913

Therein

Therein , adverb

In that or this place, time, or thing; in that particular or respect. — Wyclif
He pricketh through a fair forest, Therein is many a wild beast. — Chaucer
Bring forth abundantly in the earth, and multiply therein. — Gen. ix. 7
Therein our letters do not well agree. — Shakespeare