An effective barrier of body fluids used to prevent the spread of human immunodeficiency virus (HIV), the virus that causes acquired immune deficiency syndrome (AIDS) and other diseases transmitted through sex, is the dental dam. Less known than its present-day role in disease prevention, and that it was originally created in 1862 as a tool allowing dentists a saliva-free space on which to grind or drill teeth, is the fact that it was invented in Monticello, New York.
The beneficent inventor donated the intellectual property rights to his invention for the public good. It got him internationally recognized, but it never earned him a dime. Sanford Christie Barnum, son of George W. and Caroline Griswold (Clowes) Barnum, was born in Oakland Valley, Town of Forestburgh, Sullivan County, New York, on August 24, 1838. Dr. Barnum obtained his early education at the public schools, and at the Monticello Academy, a well known private educational institution of that time. The academy was located at the corner of Landfield and Bushnell avenues, the present site of a county-owned parking lot near the Lawrence H. Cooke Sullivan County Court House. In 1858, at the age of eighteen, Dr. Barnum entered the office of his uncle, Dr. Joseph Clowes, of New York, as a dental student, and four years later commenced practice at Monticello, New York.
Not satisfied with his limited knowledge of the science of his profession he returned to New York and attended two courses at the New York College of Dentistry, from which he graduated December 2, 1868 with the degree of Doctor of Dental Surgery, one of the school's first graduates. His professional work, both operative and prosthetic, early earned for him an enviable reputation.
After his graduation he opened offices in his uncle's house in New York City, where he soon acquired a lucrative practice. It was, however, during his residence at Monticello in 1862, that he conceived the idea and made practical the Rubber Dam in dental operations. He used it first in the mouth of a patient, Mr. Robert C. Benedict, who according to Hamilton Child's Gazetteer and Business Directory of Sullivan County for 1872-1873, was a jeweler employed at Strong, Stern & Co. on Main Street (now Broadway) in Monticello.
When Dr. Barnum came to New York in 1864 to practice with his uncle, Dr. Clowes, to whom he demonstrated his discovery, and who quickly saw the great advantage of the dam, he requested the youthful Barnum to present it to the profession as a gift. This advice was seconded by another close friend, Dr. John Allen. Dr. Barnum was of an open generous nature and possessed the highest professional ideals; he decided to forego the opportunity of making a fortune, which his highly useful invention afforded, and presented it as a free gift to "Barnum's Rubber Dam" is referred to as an excellent idea by Dr. O.S. Latimer, Dental Cosmos Vol. VI, August 1864.
This is the first record, but it seems to have been known before, to New York dentists. The profession was quick to recognize the value of the invention and his donation gave him a world-wide reputation. He was presented with testimonials as tokens of appreciation by various dental societies. At a meeting of the American Dental Association held in Nashville, Tenn., August, 1870, the following Preamble and Resolution was unanimously adopted:
WHEREAS, In view of the fact that Dr. Sanford C. Barnum of New York has devised and presented to the Dental Profession the best method of protecting cavities against moisture during the operation of filling teeth. And in testimony of its highest appreciation of this valuable improvement. RESOLVED, That the thanks of the American Dental Association be and hereby are tendered to Dr. Sanford C. Barnum for the invention, perfection, introduction, and donation of the Rubber Dam to the Dental Profession. Ira A. Salmon, Cor. Sec. American Dental Association.
In the same year, 1870, he was presented by the American Dental Association with a large gold medal "In appreciation of the great value of his invention of the Rubber Dam, and of the true professional spirit in which it was given to the world."
He was also presented with a handsome hunting case gold watch and heavy gold chain, the former of which bears the following inscription: "Presented to Doctor Sanford C. Barnum by his professional friends for his valuable gift to the profession 'The Rubber Dam.'" In 1875 Dr. Barnum was presented with a jeweled gold medal surrounded by a beautiful olive branch wreath in gold and attached to a brooch set with gold bearing quartz by the California State Dental Association. Another token of appreciation was a silver mounted album containing the portraits of twenty-two European dentists, bearing the following inscription: "The American Dental Society of Europe to Dr. S.C. Barnum in token of their appreciation of the Rubber Dam, 1876."
He remained with Dr. Clowes until 1878, then left him and practiced for himself until ill health obliged him to retire. During the last ten years of his practice he was afflicted with chronic meningitis, the excruciating pains of which were borne with a resignation so perfect that none but his most intimate friends knew of his suffering. His disease was not properly diagnosed, and its true nature was only revealed by a post-mortem examination, so that he was precluded from a measure of relief which a knowledge of his difficulty might have brought him.
The last two years of his life were attended with such extreme suffering that he was obliged to give up the practice of his profession, and at his father's home in Monticello, New York, await his end with such fortitude as he could summon. Notwithstanding the seat of his disease was in close proximity to the brain, his mind was always clear and he cherished to the last the happiest and the most pleasant recollections of his professional career and the multitude of his associates who had been so just in according to him honors commensurate with his work.
During his last illness he was greatly worried by jealous rivals who claimed priority of invention, which was not proven. Another incident of his last days was the report started by some busy-body that he was financially embarrassed and asked each member of the profession to mail him a dollar. This was painful to Barnum and in a card he feelingly contradicted it and returned the money whenever he could. 
Dr. Barnum never married. He died in Monticello, New York, December 24, 1885, at his father's residence, which Edward F. Curley's Old Monticello places on Oakley Avenue (later known as Red Lane, now Lakewood Avenue), at the age of 47 years and 4 months. In later years the residence was acquired by an Irish emigrant named Martin Toohey who operated it with his wife for a period of years under the name "Sunset Villa". In 1922-23, help-wanted ads appeared in The Republican Watchman for young men and women to deliver cards door-to-door, applicants to apply at "Sunset Villa, 21 Oakley Ave." Dr. Barnum's one-time dental office was later operated as the Sunset Villa boarding house on Oakley Avenue. According to Henry Macadam, a relative of the former owners, "It stood where the present medical services building now stands, on the east side of Oakley Avenue on the crest of the hill that slopes down to Fulton St. Sometime in the 1970s it was torn down."
Dr. Barnum's dental laboratory and residence was on the present site of the medical complex of Hudson River Health Care, which happens to house AIDS Related Community Services, at 23 Lakewood Avenue. The former dental office on the road now called Lakewood Avenue, turned boarding house, was described in a 1917 newspaper ad promoting its sale as "located in one of the most attractive and select parts of the village. [Twenty] sleeping rooms, large parlors, three dining rooms, conservatory, and kitchens, large barn, suitable for garage; one acre of ground, several fine fruit trees..."
Dr. Barnum is buried in St. John's Cemetery, Monticello (see above). He was a member of the Dental Society of the State of New York, the First District Dental Society and various local societies. He also was a member of the First Division, Third Brigade of the Seventh Regiment, National Guard of the State of New York, and received his honorable discharge in 1873. By religious belief he was a Universalist, a denomination which merged with Unitarianism in 1961 to form the Unitarian Universalist Association of Congregations, a spiritual disciple of Dr. Edwin Hubbell Chapin.
After Dr. Chapin's death, he worshiped with Dr. George Mortimer Pullman for whom he had a strong personal attachment. Dr. Barnum acquired a good practice and was a thorough, faithful and excellent operator; of a genial, happy disposition; beloved by all who knew him, earnest and straightforward in all relations of life. To his credit be it said he generously gave his discovery
"The Rubber Dam," and he will ever be known as the profession's benefactor, who made it possible "to govern the tide and command it to go hence that we may approach the wreck on the beach and repair the breaks in the hull that the ship may continue to sail on its mission of usefulness."
Dental Dams and Health Promotion
The above is based on a biographical sketch of Sanford Christie Barnum, "the profession's benefactor, the originator of the rubber dam," by Burton Lee Thorpe, DDS, of St. Louis, Missouri, available on the web in The Dental Review, Vol. 17 (1903), as well as Biographies of the founders, ex-presidents, prominent early members and others of the Massachusetts Dental Society (1914), where Dr. Barnum is included as an honorary member; with insertions from various sources added by Tom Rue, author of Monticello (Arcadia Publishers, 2010).