I would like to know the History of Rings Sanatorium which was located
in Arlington Mass in 1925.  My mother's birth certificate list Rings
Sanatorium as her mother's residence.  My Mother recently died and she
suffered manic depression her whole life and I am wondering if her
mother's residence was Rings Sanatorium due to mental illness.

I have not found any information about this particular sanatorium, but
I can tell you that most of the people in sanatoriums at that time
would have been tuberculosis patients rather than mentally ill
persons. I had a great-aunt who spent several years in a sanatorium in
the 1920s because of TB. Today we may think "insane asylum" when we
see the word "sanatorium," but in the early part of the Twentieth
Century most sanatoria were treatment facilities for physical
illnesses, with a major focus on tuberculosis.

I found an interesting bit of info.  This website lists the
correspondence of a Warren H. Manning and one of the names on the list
is a Dr. Ring Sanatorium from Arlington Heights Mass.  His name
appears about halfway down the list.  I'm not sure what this means but
maybe it helps.  There is also an Ring & Stearns sanitorium listed in
Mass:

http://library.uml.edu/clh/client.htm

There is also a mention of a Ring Sanatorium Hospital (no location)
here at #23 at the bottom of the page.  Both the collection listed
here and my above comment can be accessed apparently through the
libraries listed as owning them, maybe you can track down these
collections.

http://www-sul.stanford.edu/depts/hasrg/ablit/amerlit/asaroyan.html

This excerp from a book on the life of Babe Ruth mentions the sanitarium:

http://www.amazon.com/gp/reader/067176070X/ref=sib_aps_pg/102-8845167-2680159?p=S09T&checkSum=Y%2BZgqDajL%2F%2Fcf2vCYiy%2BGGpED6SSdMa72KqOhxor4tE%3D&keywords=%22ring%20sanitarium%22#reader-link

If the link doesn't work go to www.amazon.com and enter the search
"ring sanitarium" and it will appear.

Bowler-ga

This website tells you where to locate the microfilm of the 1930
census for those that were residing at the institution.  See 9-165:

http://www.us-census.org/states/massachusetts/teams/middlesex1930-t626-913.htm

Sorry for all the comments.  My last bit of info is the contact
information for the Arlington Historical Society which may be of help:

                                      The Arlington Historical Society 
                                      7 Jason Street 
                                      Arlington, MA 02174  
                                      Phone: (781) 648-4300.