Heat can now be abstracted by a very simple process, till the degree of cold be of almost any required intensity.—Ed.

It is impossible to compare a degree of heat with a degree of cold, without the assumption of some arbitrary test, to which the degrees are to be referred. In the next sentence Bacon appears to have taken the power of animal life to support heat or cold as the test, and then the comparison can only be between the degree of heat or of cold that will produce death.

It may often be observed on the leaves of the lime and other trees.