“But yet on occasion of this opinion of Paracelsus, perhaps it will not be impertinent if before I proceed, I acquaint your lordship with a Conceit of that deservedly Famous Mechanician and Chymist, _Cornelius Drebell_, who among other strange things that he performed, is affirmed (by more than a few credible Persons) to have contrived for the late learned King _James_, a vessel to go under Water; of which tryal was made in the _Thames_ with admirable success, the vessel carrying twelve Rowers besides Passengers; one of which is yet alive, and related to an excellent Mathematician that informed me of it. Now that for which I mention this story is, That having had the curiosity and opportunity to make particular Enquiries among the Relations of _Drebell_, and especially of an ingenious Physitian that marryed his daughter, concerning the grounds upon which he conceived it feasible to make men unaccustomed to continue so long under Water without suffocation, or (as the lately mention’d Person that went in the Vessel affirms) without inconvenience, I was answered that _Drebell_ conceived, that ’tis not the whole body of the air but a certain Quintessence (as Chymists speake) or spirituous part of it that makes it fit for respiration, which being spent the remaining grosser body, or carcase (if I may so call it) of the Air, is unable to cherish the vital flame residing in the heart: so that (for ought I could gather) besides the Mechanicall contrivance of his vessel he had a Chymicall liquor, which he accounted the chief secret of his Submarine Navigation. For when from time to time he perceived that the finer and purer part of the Air was consumed or over-clogged by the respiration, and steams of those that went in his ship, he would, by unstopping a vessel full of the liquor speedily restore to the troubled air such a proportion of vital parts as would make it again for a good while fit for Respiration. Whether by dissipating or precipitating the grosser exhalations, or by some other intelligible way, I must not now stay to examine, contenting myself to add, that having had the opportunity to do some service to those of his Relations, that were most intimate with him, and having made it my business to learn what the strange liquor might be, they constantly affirmed that _Drebell_ would never disclose the Liquor unto any, nor so much as tell the matter whereof he made it, to above one Person, who himself assured me what it was.” It is much to be wished that fuller accounts were extant respecting Drebbel’s boat, and the methods he employed to enable his passengers to breathe under water. W. B. Rye in one of the notes to his work “England as seen by Foreigners” (1865, p. 232), gives a carefully compiled account of Drebbel’s inventions and quotes from a Dutch Chronicle of Alkmaar, by C. van der Wonde (1645), a passage relating to his submarine boat.