A man's Ni is his life. It is the same as his breath and that which gives him his strength. It is the Ni which keeps the inside of a man clean. If the Ni is weak, he cannot perform this office and if it goes away the man dies. Niya is the ghost or spirit which is given to a man at birth and is that which causes the Ni. The Lakota have a ceremony which they call Ini kaga or Inipi. The white people call it taking a sweat bath. The idea of the Lakota is that the Inipi makes man's spirit strong so that it may cleanse all within the body and so that the Ni may drive from his body all that makes him tired or that causes disease or that causes him to have evil thoughts. The ceremony must be performed in a ini ti or what the white people call a sweatlodge. The ini ti must be made according to Lakota custom; otherwise, the ceremony would be of no avail.
Wowihanble is the name for a supernatural communication. It is what the white people call a holy dream or vision. In former times, if a man wished to know the will of his god he sought a vision. The term for this is ihanblapi. To seek such a vision a Lakota must think about it all the time, but first strengthen his spirit by the inikaga.