FROM whence, again, it is likewise a Key to Discover the Nature of Bodies. For how far soever we can attain to Mingle, or to Make them, we may also know what they are.
2. §. For Bodies are mingleable, either of themselves, or by some Third. As to those which mingle of themselves, we may certainly con∣clude, That there is a congruity betwixt them, in some respect or other. So upon various Tryals I find, That Essential Oyls do more easily im∣bibe an Acid, then an Alkaly. Whence it is evident, That there is some Congruity and Similitude betwixt Essentian Oyls, and an Acid, which there is not betwixt the said Oyls and an Alkaly.
3. §. As to those that mingle only be some third; we may also cer∣tainly conclude, That though the two extreams are unlike; yet that they have both of them some congruity with that third, by which they are united.
4. §. Moreover, We may make a Judgment from the manner or Degree of Mixture. Thus the Acid Spirit of Nitre, as is said, will coa∣gulate Oyl-Olive, and render it consistent. Whence it might be thought, That any other strong Acid will do the like; and that therefore, there is no great difference in the Nature of the said Acid Liquors. But the contrary hereunto, is proved by Experiment. For having digested the same Oyl in the same manner, and for a much longer time, with strong Oyl of Sulphur; although it thence acquired some change of Colour, yet not any Consistence.
5. §. Again, Because the said Spirit of Nitre coagulates Oyl-Olive; it might be expected, it should have the same effect upon Oyl of Ani∣seeds; or, at least, that if other Acids will Coagulate Oyl of Aniseeds, that this should do it best. But Experiment proveth the contrary. For of all I have tryed, Oyl of Vitriol is the only Acid that doth it instan∣taneously. Oyl of Sulphur, if very strong, will do it; but not so soon,