Double-focusing, history

Johnson = 90° = 90°). The history of double-focusing sector field mass spectrometry is... 

Since each scientific discipline has its own fundamental concepts, methods, and theories, philosophy of chemistry reaches a state of maturity, in my view (see the last part of this chapter), when it focuses on peculiarities of chemistry. This requires not only a double competence in chemistry and philosophy, but also a deep understanding of the history of chemistry because our present scientific disciplines, with all their peculiarities, are historical entities, snapshots in a process of development. Thus, unlike general philosophers of science, with their eternal, albeit sometimes personal, ideas of general science, many philosophers of chemistry do merge with historians of chemistry to analyze fundamental concepts, methods, and theories in modem chemistry. It is in these areas where many studies have been done in the past decade, such that I can give only a brief list of the most important topics. 

Before moving on to phase two of the history, we might just return to Reinitzer, the discoverer of liquid crystals, and recognize the quality of his powers of observation, for not only did he focus on the color effects and double melting, but also he noted the blue color appearing in the isotropic melt just before the sample turned into the cloudy cholesteric phase. About this, he said the following there appeared (in the clear melt) at a certain point a deep blue colour which spread rapidly through the whole mass and almost as quickly disappeared. 

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