Paper, 'An essay, of the proportion of the fixed salt of one plant, or part of a plant, to the fixed salt of an other: and to all the other principles, in any one plant' by Nehemiah Grew Grew describes his efforts to analyse the constituting or compounding parts of plants through distillation, in order to examine the volatile parts, and calcination, to examine the fixed parts. Grew details his experiments on olibanum [frankincense], asafoetida, gum arabic, euphorbium, myrrh, opium, aloe, and scammony. Subject: Chemistry 8 March 1676