Any Injun that give away the secret was killed and rubbed off the rolls of the tribe and buried in disgrace upon the plains of Oregon.

And the doctor was made a blood brother of the chief, and learnt the secret of that medicine.

Finally he got the chief to see as it wasn't Christian to hold back that there medicine from the world no longer, and the chief, his heart was softened, and he says to go.
"Go, my brother," he says, "and give to the pale faces the medicine that has been kept secret fur thousands and thousands of years among the Siwash Injuns on the plains of Oregon." And he went.

It wasn't that he wanted to make no money out of that there medicine.

He could of made all the money he wanted being a doctor in the reg'lar way.