The substance of them indeed, has so many excellent properties, scarce to be met with in any other body in the world, that I have often wondered that so little use is made of it, and those onely vile and sordid; certainly, if it were well consider’d, it would afford much greater conveniencies. That use which the Divers are said to make of it, seems, if true, very strange, but having made trial of it my self, by dipping a small piece of it in very good Sallet-oyl, and putting it in my mouth, and then keeping my mouth and nose under water, I could not find any such thing; for I was as soon out of breath as if I had had no Sponge, nor could I fetch my breath without taking in water at my mouth; but I am very apt to think, that were there a contrivance whereby the expir’d air might be forc’d to pass through a wet or oyly Sponge before it were again inspir’d, it might much cleanse, and strain away from the Air divers fuliginous and other noisome steams, and the dipping of it in certain liquors might, perhaps, so renew that property in the Air which it loses in the Lungs, by being breath’d, that one square foot of Air might last a man for respiration much longer, perhaps, then ten will now serve him of common Air. * * * * * Observ. XXIII. _Of the curious texture of _Sea-weeds_._ For curiosity and beauty, I have not among all the Plants or Vegetables I have yet observ’d, seen any one comparable to this Sea-weed I have here describ’d, of which I am able to say very little more then what is represented by the second _Figure_ of the ninth _Scheme_: Namely, that it is a Plant which grows upon the Rocks under the water, and increases and spreads it self into a great tuft, which is not onely handsomely branch’d into several leaves, but the whole surface of the Plant is cover’d over with a most curious kind of carv’d work, which consists of a texture much resembling a Honey-comb; for the whole surface on both sides is cover’d over with a multitude of very small holes, being no bigger then so many holes made with the point of a small Pinn, and rang’d in the neatest and most delicate order imaginable, they being plac’d in the manner of a _Quincunx_, or very much like the rows of the eyes of a Fly, the rows or orders being very regular, which way soever they are observ’d: what the texture was, as it appear’d through a pretty bigg Magnifying _Microscope_, I have here adjoin’d in the first _Figure_ of the 14. _Scheme._ which round Area ABCD represents a part of the surface about one eighth part of an Inch in Diameter: Those little holes, which to the eye look’d round, like so many little spots, here appear’d very regularly shap’d holes, representing almost the shape of the sole of a round toed shoe, the hinder part of which, is, as it were, trod on or cover’d by the toe of that next below it; these holes seem’d wall’d about with a very thin and transparent substance,