Joseph Leidy (1823-1891) is best known as a pioneer in the study of dinosaurs. In 1868, he guided a team that erected “the first fully articulated dinosaur skeleton display in the world.” The skeleton was put on display at the Academy of Natural Sciences of Philadelphia, which at the time was located on the northwest corner of Broad and Sansom, and it revolutionized the concept of a natural history museum.
In addition to attracting visitors to museums — lots of visitors — dinosaurs were also instrumental in getting people to think seriously about the then-novel concept of evolution. Charles Darwin’s On the Origin of Species by Natural Selection had only appeared in 1859, and it would be an understatement to say that the guardians of received wisdom were not very receptive.
Leidy, in a letter, wrote of the importance of dinosaur displays: “They break up old and rather fixed views about the world being created just as we now see it. Nothing tends so much to lead people to believe in the existence of former races of animals, as such restorations.”
Leidy was also a pioneer in the use of the microscope, which he called his “first love.” His work in this area included parasites (he found the source of trichinosis in pork and later recommended more thorough cooking as a preventive measure) and his beloved rhizopods, tiny creatures some of whom are better known as amoebas, which he lovingly reproduced in illustrations that showed a very considerable artistic talent.
Leidy was probably the first in America to use the microscope in forensic medicine. Shortly after he graduated from medical school, the coroner of Philadelphia hired him as a part-time assistant coroner. It probably didn’t hurt that the coroner was his cousin Napoleon B. Leidy. During his four years on the job (1845-1849) Joseph showed that nepotism could have an upside.
In 1846 a farmer was murdered in north Philadelphia, and a day later a man was arrested because of the blood on his clothing and also on the hatchet he was carrying. This fellow would probably have benefited from watching a few noir movies, but of course movies hadn’t been invented.
Anyway, he claimed that the blood came from chickens he had killed. Leidy threw some samples under his microscope, and declared that he was not looking at chicken blood. The suspect, apparently lacking any plausible plan B, wound up confessing.
But perhaps the thing about Leidy that most astonished his contemporaries, from students in the hallway to colleagues in the faculty lounge, was the simply amazing amount of stuff he knew about the natural world. From dinosaurs to clinical pathology, botany, zoology, rocks and gems, “if Leidy didn’t know, no one knew,” in the words of his biographer Warren.
Leidy had a happy life and many friends, and he was a pillar of three major institutions in Philadelphia: Penn’s medical school, the Academy of Natural Sciences, and the Wagner Free Institute of Science. He received the M.D. degree from Penn’s medical school in 1844 and in 1853 was appointed professor of anatomy at the medical school, a position he held for nearly four decades.
He also served as dean of the medical school, curator at the Academy of Natural Sciences and, in the 1880s, president of that institution, and as president of the Wagner Free Institute. And he taught natural history at Swarthmore for many years.
It seems that just about everybody liked Leidy. The few who didn’t like him seem to have been annoyed that, even though he was a really nice guy, you couldn’t push him around.
Leidy was born at his parents’ home, 312 North Third Street, which was conveniently next door to his father’s hat store. In 1864 he married Anna Harden, daughter of the Reverend Robert Harden of Louisville, Kentucky. In 1876 the couple adopted Allwina Franck, the orphaned daughter of a Penn engineering professor. Leidy was raised as a Lutheran, but migrated in later years to Unitarianism. His funeral was held at Frank Furness’s First Unitarian Church at 2125 Chestnut Street.
Leidy was a part of the western migration of Philadelphia during the nineteenth century. He grew up on Third Street, and in 1859 he purchased a house at 1302 Filbert Street, where he lived for many years. In the last year of his life he lived at 2125 Spruce.
The Dr. Joseph Leidy House at 1319 Locust Street was the home of Dr. Joseph Leidy, Jr., who was Professor Leidy’s nephew. It was built several years after Uncle Joseph died. Penn’s online biography of Leidy gets this wrong in the last paragraph.
The site of the Filbert Street house later became part of the City Hall Annex, which is now a hotel. Across Filbert today is the city’s criminal justice center.
Things obviously looked a bit different when Leidy was living there. For several decades he got to watch the construction of City Hall, a block away. Although the Reading Terminal was not built until after his death, there were markets on 12th Street before the Reading Terminal arrived.
A student who lived with the Leidys, Charles S. Dolley, tells us that Leidy “did most of the marketing and I frequently accompanied him to the 12th St. Market and carried home the basket of meat, fish or vegetables which he selected.” At the time hucksters would also walk the streets, calling out their wares. Fresh crabs were frequently on offer in the summer, and when Leidy heard the soft-shelled crab men “crying ‘crabs, crabs,’ he would take some change from his pocket and say, ‘Charlie, suppose you run down and get some crabs and a pitcher of beer from the corner saloon’ – a very respectable place on the corner of 13th and Filbert – in fact, right next door. Then we would have a jolly snack.” (Warren, pp. 143-145.)
Although not a great traveler, Leidy did get to Europe four times. And from time to time the world came to him. A Glorious Enterprise has a wonderful photograph on page 275 that shows Joseph Leidy standing with Edgar Allan Poe in the Academy of Natural Sciences at Broad and Sansom, during the winter of 1842-1843. The authors report that Poe spent time at the Academy researching mollusks; the photograph – a daguerrotype – is “the oldest known photograph of an American museum interior.”