Drawing of the underside of a stinging nettle leaf which was printed in a book called Micrographia" by Robert Hooke, 1665. Hooke correctly discovered that the stinging hairs were hollow "from top to bottom". He did this by observing the movement of the liquid within the sting into his finger, whilst using the micsroscope. Somewhat fancifully, he compared the base of the sting to a leather bag, and the sting itself to a glass tube. The book contains some of the most beautiful drawings of microscope observations ever made. Hooke was born in England in 1635, his main accomplishments were in the fields of physics, where he studied the action of springs, and biology."