In this thesis, I traced the development of Nuclear Magnetic Resonance (NMR) Spectroscopy through the pages of the Journal of Organic Chemistry (JOC) from the year 1956 to 1969 to understand how organic chemists and Varian Associates?the makers of the first commercial NMR spectrometers?negotiated the identity of the NMR spectrometer. The work of the organic chemists was examined through their publications in the JOC. Examining the abstracts from the JOC between the years 1956 and 1969 developed an understanding of the ways in which organic chemists used the instrument. To understand the role Varian Associates played in the development of NMR, I examined the company?s advertisements in the JOC. I traced the changes in advertising style and format in order to see how Varian Associates expected their instruments to be used. I drew three conclusions from this work: 1) organic chemists and Varian Associates together determined what an NMR spectrometer was and how it could be used; 2) the identity of the instrument was negotiated by these two groups, and the novel use of the instrument by the organic chemists and new schemes in advertising on the part of Varian Associates were attempts to shift this identity; 3) NMR spectroscopy was a domain of knowledge that was embodied in the NMR spectrometer, and that could only be accessed through the instrument.