thinks there is another light under the Earth even at Midnight, whereby many Eyes do see, which owes also its rise to the Moon. This opinion of your _Author_ I leave to be examined by those that have skill in Astronomy, and know both the Light and the Course of the Moon: I will onely say thus much, that when the Moon is concentrical, as he calls it, with the World, as when it is Full and New Moon, she doth not shine onely at night, but also in the day, and therefore she may rule the day as well as the night, and then there will be two lights for the ruling of the day, or at least there will be a strife betwixt the Sun and the Moon, which shall rule. But as for Men walking asleep by the light of the Moon, my opinion is, That blind men may walk as well by the light of the Sun, as sleeping men by the light of the Moon. Neither is it probable, that _the Moon or her Blas doth nourish Plants_; for in a cold Moon-shiny night they will often die; but it is rather the Regular motions in well tempered matter that cause fruitful productions and maturity. And so I repose my Pen, lest it trespass too much upon your Patience, resting, Madam, _Your humble and_ _faithful Servant._ [1] _Ch._ Of the Blas of Meteors. [2] _Ch._ Of Vacuum. [3] _Ch._ Of an Irregular Meteor. [4] _Ch._ Of the Earthquake. [5] _Ch._ Of the Birth or Original of Forms. IX. _MADAM,_ In my former, when I related your _Authors_ opinion, concerning Earthquakes, I forgot to tell you, that he counts the Doctrine of the Schools absurd, when they say that Air, or any Exhalation, is the cause of them: For, says he, _There is no place in the Pavements or soils of the Earth, wherein any airy body may be entertained, whether that body be a wind, or an airy exhalation._ But since I promised I would not offer to appoint or assign any natural causes of Earthquakes, I have only taken occasion hence to enquire, whether it may not be probably affirmed, that there is air in the bowels of the Earth: And to my reason it seems very probable; I mean not this Exterior air, flowing about the circumference of the Earth we inhabite; but such an airy matter as is pure, refined, and subtil, there being great difference in the Elements, as well as in all other sorts of Creatures; for what difference is there not between the natural heat of an animal, and the natural heat of the Sun? and what difference is there not between the natural moisture of an Animal, and the natural moisture of Water? And so for the Purity of Air, Dryness of Earth, and the like: Nay, there is great difference also in the production of those Effects: As for example; the heat of the Earth is not produced from the Sun, nor the natural heat in Animals, nor the natural heat in Vegetables; for if it were so, then all Creatures in one Region or place of the Earth would be of one temper. As for example: Poppy, Night-shade, Lettuce, Thyme, Sage, Parsly, &c. would be all of one temper and degree, growing all