The Winslow Chemical Laboratory was opened in 1866. The building of brick with stone trimmings was finished inside with butternut, chestnut and black walnut. The whole building was fitted for complete courses in general and analytical chemistry. The laboratory was planned and built under the direction of Prof. H.B. Nason, who was head of the department of chemistry in the Institute. The first story contained the metallurgical laboratory. The second story contained the chemical laboratory, store rooms and work rooms. The laboratory could accommodate forty students. The third story contained a lecture room, a private study, the library and a recitation room. The library of chemical books was established by a donation of several sets of journals and a gift of three hundred dollars from John F. Winslow for whom the laboratory was named.
The Winslow Laboratory was damaged by a fire in the upper story in 1884. The building was rebuilt and enlarged in 1885. The building was damaged by fire again in 1904. It was used as a laboratory until 1907 and then converted into a shop. The building, falling into disrepair, was boarded up in the early 1970s and targeted for demolition. An effort to save the building resulted in Rensselaer donating the building to the City of Troy. The city in turn agreed to lease the building to the Junior Museum, which occupied the building from 2000 to 2004. RPI then repossessed the building for use as departmental office space.