Today is the birthday of Regnier de Graaf who was born on this day in 1641 in Schoonhoven in the Netherlands. He is one of a group of medical students who studied at the University aof Leiden. They’re an odd bunch, and all interesting in their own way. The university was founded in 1575 by William I of Orange. It seems that the people of the city were asked to choose between a university and a cut in taxes. They chose the university. Good choice.
De Graaf was really interested in anatomy. He devised a syringe that was capable of injecting a wax substance into the veins of anatomical specimens which would then harden. This made their structure much clearer during dissection. His fellow student, Frederik Ruysch put this method to a very unusual use, but we’ll save that for his birthday in March (or just look him up now, you won’t be disappointed).
To get back to Regnier, his particular field of interest was the reproductive organs of mammals. Mainly he worked on rabbits but also performed some human dissections. He discovered the mass of tiny tubes that make up the inside of a testicle and concluded that it must be where semen came from. De Graaf’s publishing of his findings sparked a massive row, first with former tutor and fellow students and then with members of the Royal Society in London over who had come up with the idea first. It ended with de Graaf sending a dormouse testicle in a bottle to the Royal Society. They had to admit that he had made his point but wished that he had sent them a larger testicle. His book, with the catchy title of ‘Treatise concerning the generative organs of men; on enemas and on the use of syringes in anatomy’ also contains a method of filling a dissected penis with water to make it erect, thus creating hours of fun for medical students for hundreds of years to come.
Since the time of Aristotle in had been generally assumed that in humans, fertilization occurred due to a mixing of semen with menstrual blood in the womb. Anatomists had noticed ovaries and called them female testes. They didn’t really know what they did though. De Graaf suggested that fertilization took place in the ovary, involving an egg that originated and pre-existed there. He knew that the already fertilised egg must travel down the fallopian tube into the womb because he had observed ectopic pregnancies.
It also seems that he discovered and described female ejaculation. He describes ducts around the inside of the urethra, which appear to be what are now called Skene’s ducts. He describes a structure surrounding the urethral canal as a kind of female prostate which he says secretes a pituito-serous juice which makes women more libidinous with its pungency and saltiness and lubricates their sexual parts in agreeable fashion during coitus. He believed that the liquid came from a variety of sources including the urethra and vagina. He does not appear to distinguish between the lubrication of the perineum during arousal and an orgasmic ejaculate, though he does describe a fluid which rushes out with such impetus during venereal combat or libidinous imagining. This is obviously a translation as he wrote in Latin but still delightful.
He managed to make all his observations without access to a microscope, which is pretty amazing.