Besides being a stretch of clubs it is a stretch of churches.  Shrinking back from the sidewalk on the east side of the Avenue between Forty-fifth and Forty-sixth Streets is the Church of the Heavenly Rest.  So inconspicuous in appearance is it that once a passer-by commented:  “I can perceive the Heavenly, but where is the Rest?” Two blocks to the north, at the corner of Forty-eighth, is the Collegiate Church of St. Nicholas, occupying the block between Fiftieth and Fifty-first is the Cathedral, and at Fifty-third is Saint Thomas’s.  Once the tract from Forty-seventh to Fifty-first Street was occupied by the Elgin Botanical Gardens.  The story of the Gardens, says “Fifth Avenue,” “begins in 1793 in the garden of Professor Hamilton near Edinburgh, where Dr. David Hosack, a young American, who was studying with the professor, was much mortified by his ignorance of botany, with which subject the other guests were familiar.  Hosack took up the study of botany so diligently that in 1795 he was made professor of botany at Columbia College, and in 1797 held the chair of Materia Medica.  He resigned to take a similar professorship in the College of Physicians and Surgeons, where he remained until 1826.  For over twenty years he was one of the leading physicians of New York, bore a conspicuous part in all movements connected with art, drama, literature, city or State affairs, and was frequently mentioned as being, with Clinton and Hobart, ’one of the tripods upon which the city stood.’  He was one of the physicians who attended Alexander Hamilton after his fatal duel with Burr.  While professor of botany at Columbia he endeavoured to interest the State in establishing a botanical exhibit for students of medicine, but failing to accomplish this he acquired from the city, in 1801, the plot mentioned above, for the purpose of establishing a botanical garden.  In 1804 the Elgin Botanical Gardens were opened.  By 1806 two thousand species of plants with one spacious greenhouse and two hot houses, having a frontage of one hundred and eighty feet, occupied what today is one of the most valuable real estate sites in New York, the tract being now valued without buildings at over thirty million dollars.  The financial burden of maintaining the garden was more than the doctor could carry, and he appealed to the Legislature for support.  Finally on March 12, 1810, a bill was passed authorizing the State, for the purpose of promoting medical science, to buy the garden.  The doctor sold it for seventy-four thousand two hundred and sixty-eight dollars and seventy-five cents, which was twenty-eight thousand dollars less than he had spent on it.  The State finally conveyed the grounds in 1814 to Columbia College, and this property, part of which the College still holds, has largely contributed to the wealth of the great University.”