building was still too small, and in 1868 a third addition was made, which made possible 135 tables. In 1874 President Angell announced the completion of a fourth addition, a wing 95 by 30 feet, stating that as many as one hundred students at a time had been forced to wait for tables, and asserting that there was a need for more instruction in metallurgy and assaying. He added that all of the additional space now provided would be used at once. In 1880 a Laboratory of General Chemistry was set up, and a fifth addition, in the form of a second story, was made to the building. This construction was done under the supervision of Regent Andrew Climie. Meanwhile, the School of Pharmacy, which had been developed within the Chemical Laboratory, had been growing, and in 1888, although congestion had been relieved by transferring the work in hygiene to the building constructed for the laboratories of Hygiene and Physics, President Angell stated that there was urgent need for further enlargement of the building. A sixth addition was, therefore, completed in 1890, the state legislature having appropriated $21,000 for the purpose. It was added to the west end of the building. The architect was E. W. Arnold, of Detroit. The addition provided tables for eighty students, three lecture-rooms, and a pharmaceutical and chemical museum. The cost of the additions and of the original building, including some of the equipment, through 1890 totaled $55,845. Between 1895 and 1900 a Laboratory of Physical Chemistry was set up in the building, and the seventh and last addition was constructed in 1901. The building now had 362 tables. In 1903 the West Medical Building was completed, and the laboratory work in physiological chemistry was removed to it.
The building, because of its additions, is very irregular in plan, with a main section (Pharmacology) on the north which includes the old first laboratory of 1856, and an L-shaped wing on the south. The building has a maximum dimension from north to south of 160 feet and from east to west of 180 feet.
Although the principal purpose for which the building was constructed was to provide laboratory space for work in analytical chemistry, it was later used for organic chemistry, pharmaceutical chemistry, and chemical technology as well, and, until 1890, for electrotherapeutics. Later, the Hygienic Laboratory in the West Medical Building became headquarters for the work in physiological chemistry, but one laboratory, providing facilities for forty-eight students, was maintained in the Chemical Building. During the year 1896-97 more than 600 students received instruction in the laboratories of this building.
In 1909, with the completion of the new Chemistry Building, these laboratories were all moved, and the southern wing of the old Chemical Laboratory, which is in effect a separate building, was taken over by the Department of Economics, while the Department of Pharmacology occupied the northern wing. The basement of the southern section was transformed into an accounting laboratory and, until 1924, the second floor was used as a library.
With the erection of Angell Hall, provision was made for an economics-mathematics library on the third floor. The quarters in the Economics Building vacated by the library were thereafter used as a statistical laboratory, while the rear part of the pharmacology section was utilized as laboratory space for special research projects.
