The supplement to a small treatise called Salt-water sweetned shewing the great advantages both by sea and land, of sea-water made fresh. Together with the Honourable Mr. Boyle's letter, and the approbation of the Colledge of Physicians, of the wholsomness of this water. And also the conditions on which the patentees and others concern'd, do intend to contract with such as shall please to deal with them for the use of his invention.

The fore-going Dedication, Humbly of∣fered to His Majesty, having disco∣vered the Intention of this Underta∣king; it remains now to satisfie all Reasonable Scruples which have been raised concerning the Wholesomness and Cheapness of Water thus prepa∣red.

The Queries and Answers follow.

Quest. 1. IF this Water can be made in suffici∣ent quantities to serve the Ʋses of any Ship at Sea?

Ans. About Ninety Gallons may be Prepa∣red in every Twenty four Hours by an Instru∣ment of 33 Inches Diameter, which will stand under the Deck of any Ship; and it's computed that less than three Quarts is a good Allowance for any man in that time: And if a large Ship, wherein there are many men aboard, should require more Water, then two or more of the In∣struments may be had upon reasonable Terms, and one man may attend several of them.

Quest. 2. In case the Operation be by Fire, it may require a Skilful Chymist, or one knowing in such Operations, to be on Board every Ship, who will require great Wages.

Ans. There will be no occasion for any such Person, for any Sea-man may be Instructed in an Hour or two to prepare this Water.

Quest. 3. It's probable that the Engine may be frequently out of Order, and being so at Sea, where Artificers and Tools are wanting to repair it, there must necessarily follow want of Water, which will be of Ill Consequence.

Ans. This Engine is of such Contrivance, that it's never likely to be out of Order.

Q. 4. Can this Engine be of use in Stormy-weather?

Ans. Since a sufficient quantity of Fresh-water may be so easily had by this Engine, the Ma∣riners will be careful to make a good Provision of it before-hand; however 'tis not to be doubt∣ed but it will answer the worst Accidents of the greatest Storms, and have its Effect sufficiently in the worst Weather, especially considering that in such desperate Extremities men must be content with smaller Allowances.

Quest. 5. The Operation being by Fire, it may endanger the Ship, and the Smoak be very offensive?

Ans. The Engine may easily be placed in any Ship without danger of Fire, or offence of Smoak.

Quest. 6. Will not the Charge of this Instru∣ment and Materials belonging to it be very great?

Ans. It is difficult to make exact Answer to this, but an Instrument of the largest Size, with all the Materials belonging to it, will not amount to above 18 pound, and may last many years,

and according to the Rates of Ships, they may be proportion'd both in Bulk and Price. And where it may be thought necessary to make use of this Experiment on Shore, for Brewing, or other uses of a Family, Instruments and Materi∣als may be very large, and very much cheap∣er on Shore, than at Sea.

Quest. 7. Will not the Fewel be very Charge∣able, and take up much room in the Ship?

Ans. The quantity of about ninety Gallons of Water, may be prepared with less than three pecks of Coals, and proportionably with any other Fire; and the whole Room that will be taken up in the Fire, and in the few Casks to be imployed in the making and receiving this Water, will be less than the tenth part of Stow∣age now employed for Water onely, and upon a strict Computation made by the Persons con∣cern'd in this Grant, the whole charge of Water will come to less than an half penny per Gallon.

Quest. 8. Will not the Ingredients take up much Room, and be very Chargeable?

Ans. A Vessel less then a Barrel may contain enough of the Ingredients to carry a Ship to the East Indies and back again; and the Ingre∣dients for near one hundred Gallons of this Sea-water will not amount to above 12 Pence, and will be cheaper when great quantities are used at Land.

Quest. 9. Admitting this Preparation of Water may be made, and in sufficient Quantities, it may be doubted whether it be wholsome?

Ans. The Famous Lord Bacon, having writ∣ten learnedly of this Subject, had not the least thought that the Sea-Water, after it had been Dis-salted, without any Noxious addition, was Unwholesome: and it neither now is, nor ever was really doubted whether it were wholesome; However, because invidious Persons, who are no well-wishers to Ingenious Designs, may possibly raise Scruples, the Gentlemen who are concerned in this Grant, have purposely, to give Publick Satisfaction, sent a large quantity of this Water to Doctor King, a very Ingeni∣ous Physician, who is a Member of the Colledge, and of the Royal Society; who finds,

1. That it is Lighter than most of the Wa∣ters about the Town.

2. That it is without Sediment, and Trans∣parent as any other Waters.

3. That it Lathers (as they call it) with Wash-Ball or Soap, better than other Water, and with less Soap.

4. That Sugar dissolveth sooner in it, than in other Water.

5. That it Evaporates sooner than common Water.

6. That whereas common Water Putrifies and yields a Stinking Smell within a few Weeks,

this has continued Sweet and unaltered several Months, and may yet do so much longer, being still in as good condition as it was above Eight months ago, November the Fifteenth, 1683.

7. That it makes Gellies as firm and good as any Water.

8. That it Boils Pease to Tenderness, Beef, Mutton, Fish, and all other Meat, without giving it an ill Taste or Colour.

9. That it has no kind of ill Taste in it self, and Boils in Milk without Curdling.

10. That Flowers, Plants, and all Vegetables grow in it at least as well as any other Water.

11. And that small Animals live and grow in it.

Several men of great Quality, viz. The Earls of Shrowsbury, Westmorland, Mulgrave and Bur∣lington, the Lord Dunbar, Lord Lumley, Lord Falconbridge, and Lord Chumley, besides very many Gentlemen of Quality, who frequently drink Water, Officers of Sea, and Physicians, have Drunk of this Water without being in the least indispos'd after it; but, lest any doubts may re∣main after this, of the Salubrity of the said Wa∣ter, the following Testimonial of these Learn∣ed and Eminent Physicians is here inserted. And a further account of new Experiments, made by an ingenious Physician, is now at the end of this Treatise Printed.

The Approbation of the Colledge of Phy∣sicians, and other Doctors of Physick, Practising in and about London.

WHereas we have received an account in a Gazet published some months since, that the Honourable Robert Fitz-Gerald, Esq hath found out the way and means of reducing Salt-water into Fresh, in quantities sufficient to serve Ships at Sea. And for as much as some Persons may possibly make a doubt, if the said Water be wholsome after the Salt is taken out of it. We therefore, considering of what gene∣ral Advantage this useful Experiment may be, having fully inform'd our selves from Mr. Boyle, that the said Experiment is made by Fire. And having also seen an account of some Experi∣ments made by some Members of our own Bo∣dy, do declare our Opinion, that We believe the said Water is very wholesome, and may be safely used. And being further acquainted by the said Mr. Boyle, that the very few Ingre∣dients made use of in the said Operation, are fixed in the Fire, and give no noxious qua∣lity to the Water; We are therefore of Opi∣nion that the same may be safely used, and is at least as healthy as any other Water us'd at

Sea. All which we certifie (at the Request of the Honourable Robert Fitz-Gerald.)

• D. Cox, President,
• Sir C. Scarborough, Knt.
• Dr. Daniel Whistler,
• D. Weatherly,
• Dr. Will. Denton,
• Sir T. Millington Knt.
• Dr. Walter Needham,
• Dr. Thomas Short,
• Dr. Thomas Allen,
• Dr. Edmund Dickingson,
• Dr. William Croone,
• Dr. Richard Lower,
• Dr. John Windebank,
• Dr. Daniel Cox,
• Dr. James Rufine,
• Dr. Charles Conquest,
• Dr. Edmund King,
• Dr. Willowghby,
• Dr. Tho. Sydenham,
• Dr. Edward Tyson,
• Dr. Nehemiah Grew,
• Dr. David Abercromby,
• Dr. Andrew Creagh.

Though Phsiyck has always flourished in this Kingdom, yet in this Age it is in greater Per∣fection than ever; being improv'd, both as to the Practical and Speculative part, by the pre∣sent Fellows of the Famous Colledge of Phy∣sicians; who, being Men of great Practise and Eminent Learning, cannot but give full satisfaction to all such as inquire concerning the healthfulness of this Water; Their Opi∣nion being, in this particular, the more valu∣••ble, because it is to their own Disadvantage; ••nce the Brackish Waters of the Sea-Coast, and the putrifying Waters made use of at Sea, might probably have afforded them a 〈◊〉〈◊〉

number of Patients, which may hereafter be lessened by the use of this wholesome Water.

Since the first Edition of these Papers, his Majesty has been pleas'd to see some Experi∣ments, which has so convinc'd his Majesty of the healthfulness of this Water, that he has resolved to have it generally made use of in his Sea-Port Garrisons; of which an account has been given in several Gazetts, by His Ma∣jesties special Order.

The Benefits and Advantages of Sea-Water made Fresh.

MUch Stowage will be saved, so that a Ship of 50 or 60 Tun, and proportio∣nably of greater Bulk, may take in several Tuns of Goods more than formerly they used to car∣ry; which will considerably advance the Trade of all Merchants, and be of vast profit to the Masters or Owners of Ships.

The Charge of Casks is very considerable, especially when bound with Iron, as all Sea-Casks must be; And by means of this Engine, three fourths of that charge will be saved.

The tear and wear of Boats often going from Ship-board, and frequent loss of the Boats and men in Stormy Weather, and the Op∣••••••••nity of the Sea-mens being Drunk or

shoar; by which many fatal accidents do hap∣pen, (by means of having this Water-Engine) will be prevented.

Ships in long Voyages have been forc'd to run many Leagues from their intended course, which much retards their Voyage, and makes them lose fair Winds, and maintain more Sea-men at charges of Diet and Wages than they have occasion for; which inconveniencies may be prevented by having Water within themselves.

Ships are often forc'd to leave their Anchors and Cables behind them, by being forc'd in∣to dangerous Shoars upon account of taking in Fresh Water.

In the African, East and West India Voyages, great quantities of Fresh Water are necessary, which the Sea-men are forc'd to put above Deck for want of room, which is great hin∣drance to a Ships Sailing, and much endangers and weakens a Ship.

In case of Calms, which often happen in the narrow Seas, but especially near the Line, this Instrument will be of vast advantage, by af∣fording fresh and wholsome Water, instead of that which is unwholsome and offensive.

Essex, Kent, and all other the Sea-Coasts, in any part of the World, that want wholesome Water, may be easily and cheaply supplied by this means; as also Venus 〈…〉〈…〉

Windam, and all other Towns or Places that lye near the Sea, and either want good, or have Brackish Water.

In time of War, whole Navies may be re∣lieved by this Engine, and Opportunity gi∣ven of making the greatest Discoveries imagi∣nable.

It is further to be considered, that hitherto the richest and ablest bodied Sea-men have been averse from undertaking long Voyages, by reason of endangering their Healths, and Lives, by making use of putrified Water, which inconvenience is not now to be feared, their be∣ing such useful hopes of Fresh Water by the use of this Engine; and possibly a smaller num∣ber of men may serve the use of Ships than do at present, by which much Charges will be saved to the Masters and Owners of Ships; and Merchants may Trade upon easier Terms.

In Portsmouth, Rochester, the Fenns of Lin∣colnshire, and any other places near the Sea, where Waters are Brackish, and consequently unwholsome, this Engine, &c. may be very useful, and where there is room enough to place it, very great quantities of Water may be had for the use of whole Families, and the Ingredients when used in great quantities may be afforded at a cheaper Rate.

A LETTER of Mr. BOYLE's to the Learned Dr. JOHN BEALE, Fellow of the Royal So∣ciety, concerning Fresh-water made out of Sea-water: Printed at the desire of the Patentees.

SIR,

TO give you a short Account (suitable to the little time I have to do it in,) of the Transaction, which I suppose must have given the rise to the Mention made of my Name in the publick Gazette,: I must inform you, that one of my nearest Relations, (Captain Fitz-Gerald,) and some other Worthy Gentlemen, having ac∣quainted his Majesty, that They had an Invention for making Sea-water sweet and wholsom in great quantity, and with small Charge, and that I had examin'd, and did approve the Water so prepar'd; His Majesty was pleas'd with very Gracious Ex∣pressions, to command Me to attend him with a further and more particular Information. Ha∣ving readily obey'd this Order, and been made ac∣quainted with the Objections the King thought fit to make against the Practicableness of the Inven∣tion; which, (tho a private Man had urg'd them,) I should think the most Judicious that have been fram'd against it; I humbly presented to him, that I look't upon this Invention as Comprizing two differing things; a Mechanical part, which related to the Engine it self, and the use of it a Ship-board▪ and a Physical part which 〈◊〉〈◊〉

the Potableness and Wholsomness of the Liquour. About the former of these I did not pretend to clear the Difficulties, especially such strong ones, as His Majesty had propos'd; but left it to the Paten∣tees to give him Satisfaction, which they were in a readiness to offer. But as to the Wholsomness of the prepar'd Water, I had made some Tryals upon the Liquour, which gave me no just Grounds of su∣specting it to be unwholsom, but several Motives to believe it well condition'd, and of great use to Na∣vigators, and not to them only. And having here∣upon briefly acquainted His Majesty with the chief Tryals I had made to examin this Sweetned Wa∣ter, He was pleas'd to look upon them as Satisfacto∣ry, and vouchsafed on that occasion to Discourse as a Virtuoso, of the Sea and Brackish-waters, and gave me some new, as well instructive Observations about them: and in conclusion, dismiss'd the Patentees with a Gracious Promise of his Royal Protection, and peculiar Favour.

To this short Narrative it now remains, that I briefly Subjoyn the chief things that perswaded me of the Salubrity of this Water, (whence may be justly and easily inferr'd, the Ʋtility the Publick may receive by a cheap and easie way of preparing it.) First, then I consider'd that almost all the Rain-water that falls from the Clouds on the Main Oce∣an, and which (except perhaps in very few Places in Torrid Climates) is unquestionably receiv'd as wholsom, must be afforded by the Sea, and conse∣quently

be but Sea-water freed from its Salt, (ac∣cording to the famous Motto, Redit Agmine dulci.) Next I found, (as his Majesty himself had done,) that the Liquour was well tasted, and without any sensible Brackishness; and some of it continued for between 4 or 5 Months in a large Christal Bottle, that I purposely kept unstopt, and for the most part in a South Window, where it neither did, nor probably in a long time, will putrifie, or so much as appear troubled or less transparent; during which time, it was with Approbation tasted and smell'd by several Learned Physicians of the famous Colledge of London. Thirdly, I found it laver very well, which most Pump-waters, and many o∣thers that have some little (tho unperceiv'd) com∣mon Salt in them, will not do. Fourthly, this Wa∣ter will boyl Pease tender, which amongst Sea∣men is one of the principal signs of good Water. Fifthly, In very good Ballances, with an Instrument that I purposely caus'd to be made for the nice weighing of Liquours, I found this Water far less heavy than one would expect; for if it differ'd at all in weight from the like quantity of undistill'd Water, (I speak with an If, because it is far more difficult to be exact in such nice Tryals, than the unpractic'd will imagine) the difference was not considerable, being but one part in 400, and that dif∣ference is very small in comparison of that which Navigators and learned Authors relate to be ob∣servable in natural Waters, all of them good 〈◊〉〈◊〉

potable: I might tell you on this Occasion, that the last Great Duke of Tuscany, who was an Emi∣nent Virtuoso, and the Patron of the celebrated Academy of the Lyncean Philosophers, is af∣firm'd, among other prudent Courses that he took for his Health, whereof he was very Sollicitous, to have constantly made use of distill'd Water, when he us'd any Water, for his own Drinking. And I could add other things favourable enough to the Patentees Water, if Haste, and perhaps Discre∣tion too, did not oblige me to leave them yet un∣mention'd, that I might now have time to say some∣what of the main thing of all that convinced me of the Saltlessness of the Water I speak of. I consi∣der'd then, Sixthly, that the thing that was aim'd at by those ingenious men, that at differing times, and in several Countries have attempted to make Sea-water sweet, and the thing that was requir'd by proposing Recompences, or otherwise to encou∣rage the Makers of such Attempts, was to free the Sea-water from the Brackishness without any noxi∣ous Additament: so that on all sides it was taken for granted, that the only thing that kept the Sea-wa¦ter from being safely Potable, was its Brackishness From which reflection it was natural for Me to infer a Conclusion very favourable to our prepar'd Water. For having long since written a short Dis∣course of the Saltness of the Sea; I had been in dustrious to devise ways of comparing Waters 〈…〉〈…〉. And by these I found th••

Patentees water to be more free from Common-salt, than Waters that are usually drunk here in London, of which I remember I shewed those Gentlemen an experiment that surpriz'd, as well as convinc'd them. And that which more satisfi'd me my self, was a Tryal that I carefully made by a way which having men∣tion'd, but not yet (for want of opportunity) disclos'd to His Majesty, the Respect I owe Him forbids me to impart without His leave: On which account I hope you'll be content to be at present assur'd of these two Things; One, that by this way of Tryal, I found▪ (what possibly you will think strange;) that if there were in Water, so much as one Grain of Salt, in above two Ounces of Water, I could readily disco∣ver it: The other, that even by this critical Exa∣men, I could not detect so much as a thousandth par•• of Salt in Our Prepar'd Water; whereas I found by Tryals purposely and carefully made, that ou•• English Sea-water contain'd a 44, or 45th par•• of good dry Salt; or, which is all one, that 44 Pints or near so many Pounds of Marine Water, woul•• yield about one Pound of dry Common-Salt.

Thus Sir, you have a short and Art-less Account such as my haste will permit, and the nature of th•• Subject requires, of my part in promoting this pro¦fitable Invention; to which I own my self a grea•• well-wisher, not out of any private Interest (th•••• that was obligingly proffer'd me by the Patentees but as I think the bringing it into general us•• may prove a real Service to Mankind, upon th••

Score of divers Ʋtilities and Advantages, which yet, (tho I had leisure,) I should think very need∣less to enumerate to so discerning a Person as Dr. B. to whom I shall therefore hasten to subscribe my self,

SIR,

A very Affectionate Friend, and Humble Servant, R. BOYLE.