Simplicia, vegetable juices, and the ultimate principles of plants

2 Simplicia, vegetable juices, and the ultimate principles of plants 

But Boerhaave s history of plants was not merely a descriptive natural history. It also included considerations about the chemical differences in the native juices of plants and their successive transformation during plants maturation and seasonal changes. According to Boerhaave, plant juices were gradually changed and further elaborated chemically in the plant. An example was the native oil of the bark  

9 On Boerhaave s plant chemistry, see also Klein [2003b], 

Yet despite his occasional comparison of the native juices of plants with materials obtained in the laboratory, and also despite his chemical explanation for the formation of different native juices of plants, Boerhaave did not really abolish the divide between simplicia and native juices of plants on the one hand, and the chemically extracted plant materials on the other. He never summarized his comparisons, and he never presented a list of plant materials comprising both the namral juices of plants and chemically separated materials. On the contrary, Boerhaave sorted out and clearly set apart from the natural juices of plants a particular group of chemically separated plant materials. These were the substances defined in the tradition of chemical philosophy as the ultimate chemical principles of natural bodies. In the theoretical part of his Elementa Chemiae he presented a short list of these simple principles contained in plants  

A spiritus rector, or presiding spirit, a sovereign oil, the true seat of this spirit, an acid salt, a neutral salt, an alcaline salt, either fix d or volatile, an oil mixed with salt after the manner of a soap, and a saponaceous juice hence arising, an oil firmly adhering to the earth, so as scarce to be separable therefrom and lastly earth itself, the genuine firm basis of all the rest these are the principles, or matters, which a well-conducted chemistry has hitherto produced from plants.  

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