Thank you Danielle for taking an interest in the profile. I have spent the last year researching all the Joseph Thériaults I could find baptized in Québec parish records around the time of his birth, 1878, give or take a year. All of the other Joseph Thériaults in the 1891 census, born 1876-1880, including those you have pointed out, have corresponding baptismal records contemporaneously with their birth. I researched Joseph Miville/Deschenes in the census born 1877-1880 as well in case he was living with his mother's family and was misnamed in the census. I find no trace of Joseph Thériault in burial records prior to the 1881 census. All of the baptisms for a Joseph Thériault in that time frame can be found in the burial records or living with their family in 1891. I have't found him with any of his mother's siblings census entries. Which is why I postulate it this Joseph Thériault who is the child in the orphanage.
The reason I was researching him is that Joseph Morin, an adoptee, is my great grandfather. It was suggested to me that Joseph Thériault and my grandfather, Joseph Morin, are the same person. The DNA disproves any link between Joseph Morin and any Thériault or Miville/Deschenes.I was looking to find a trace of Joseph Thériault after his father left him in Québec just for completion.
Christine