It was under the same roof as the North Hall that the much needed lecture rooms were raised. There were at first three. Later when a large number of small rooms for private teaching were made in the Pfeiffer Building, two of the lecture rooms proper were knocked into one, thereby giving the College one room large enough to accommodate (if desks were removed) about a hundred people. It was chiefly by pressure from Miss Gladstone that an infirmary or hospital was built, adjoining the North Hall, but with its separate entrance. This has often proved useful in checking the spread of infectious ailments among the students or the servants. A chemical laboratory had already been erected in the garden at a respectful distance from the original Hall. Its equipment was mainly the task of Miss Penelope Lawrence, afterwards headmistress of Roedean School, Brighton. A laboratory for the study of Biological subjects was provided in the town in 1884, a disused Congregational chapel being adapted to the purpose. Mrs. Sidgwick and her sister, Miss Alice Balfour, were the principal donors, and the laboratory was appropriately named after their brother, Francis Maitland Balfour, whose promising and already distinguished career had been cut short by an accident in the Alps. For many years, these two laboratories formed the training ground of a large number of students, who did much to supply the demand for improved science teaching in schools and colleges for girls. In the Chemical Laboratory Miss Freund and in the Balfour Laboratory Miss Greenwood (now Mrs. Bidder) and Miss Saunders presided for many years, carrying on both teaching and research. (Both Miss Freund and Mrs. Bidder were former students of Girton.) In course of time, the opening of the University laboratories to women students rendered these buildings less necessary, and they are at present let for University purposes.