If you look at the KJV which is probably what Russell used, see how the word "publish" is used, not about publishing something in printed form.
Mark 5:20 King James Version (KJV)
20 And he departed, and began to publish in Decapolis how great things Jesus had done for him: and all men did marvel.
PUB'LISH, v.t. L.publico. See Public.
1. To discover or make known to mankind or to people in general what before was private or unknown; to divulge, as a private transaction; to promulgate or proclaim, as a law or edict. We publish a secret, by telling it to people without reserve. Laws are published by printing or by proclamation. Christ and his apostles published the glad tidings of salvation.
Th' unwearied sun, from day to day,
Does his Creator's power display;
And publishes to every land
The work of an Almighty hand.