Stephen Hales

"And if we reflect upon the discoveries that have been made in the animal œconomy, we shall find that the most considerable and rational accounts of it have been chiefly owing to the statical examination of their fluids, viz. by enquiring what quantity of fluids, and solids dissolved into fluids, the animal daily takes in for its support and nourishment: And with what force and different rapidities those fluids are carried about in their proper channels, according to the different secretions that are to be made from them: And in what proportion the recrementitious fluid is conveyed away, to make room for fresh supplies; and what portion of this recrement nature allots to be carried off, by the several kinds of emunctories and excretory ducts."

"And since in vegetables, their growth and the preservation of their vegetable life is promoted and maintained, as in animals, by the very plentiful and regular motion of their fluids, which are the vehicles ordained by nature, to carry proper nutriment to every part; it is therefore reasonable to hope, that in them also, by the same method of inquiry, considerable discoveries may in time be made, there being, in many respects, a great analogy between plants and animals."

"The bodies which I distilled... (Fig. 38.) were Horn, calculus humanus, Oystershell, Oak, Mustard seed, Indian-wheat, se, Tobacco, oil of Anniseed, oil of Olives, Honey, Wax, Sugar, , , Earth, Walton Mineral, sea Salt, Salt-petre, Tartar, Sal Tartar, , Minium."

"We have from the foregoing Experiments many proofs of the very great and different quantities of moisture imbibed and perspired by different kinds of Trees, and also of the influence of the several states of the air, as to warm or cold, wet or dry, have on that perspiration. We see also what stores of moisture nature has provided in the Earth against a dry season, to answer this great expence of it in the production and support of vegetables; how far the dew can contribute to this supply, and how insufficient its small quantity is towards making good the great demands of perspiration: And that plants can plentifully imbibe moisture thro' their stems and leaves as well as perspire it."

"We have... many proofs of the great force with which plants and their several branches and leaves imbibe moisture, up their capillary sap vessels: The great influence the perspiring leaves have in this work..."

"I have here, and as occasion offered under several of the foregoing Experiments, only touched upon a few of the most obvious instances, wherein these kind of researches may possibly be of service in giving us useful hints in the culture of plants: Tho' I am very sensible, that it is from long experience chiefly that we are to expect the most certain rules of practice, yet it is withal to be remembred, that the likeliest method to enable us to make the most judicious observations, and to put us upon the most probable means of improving any art, is to get the best insight we can into the nature and properties of those things which we are desirous to cultivate and improve."

"I was at first much discouraged, when I reflected on my Rashness, in venturing on an Undertaking, which had baffled the repeated Attempts of the best Philosophers and Chymists, both Ancient and Modern: In so much that they looked upon it as almost impracticable to find out any way to procure a wholesome Drink from Sea-Water."

"I shall... give an Account of what has been formerly attempted for making Sea-Water drinkable, especially what was done by Mr. Walcot and Mr. Fitz-gerald in King Charles the Second's Time."

"St. Basil, in his Homilies, says that when Men were cast on an Island, where there was no fresh Water; and they boiled Sea-Water; and catched the Vapour with Sponges, which they squeezed into another Boiler; and having passed thus, four or five Times from Boilers thro' Sponges, it became drinkable. This tedious way was used before the method of Disttiling was known, which was an Invention of the Arabs."

"Johannes Gadesden [i.e.,] Johannes Anglicus, Anno 1516, says that Sea-Water may be sweetened four ways, viz. by filtrating thro' Sand: By clean Linnen laid over a Boiler, and squeesing the Moisture out, as from the Sponges: By Distillation: As alfo by thin Bowls made of white Virgin Wax, which 'tis said will free the Water from its Saltness, and from some part of its nauseous Bitter. But this is only a matter of curiosity, because but a very small Quantity can be thus prepared; and in order to make those waxen Bowls fit for farther Filtration, they must be cleansed from the Salt, by being washed in fresh Water."

"About the Year 1675, William Walcot, Brother to Sir , obtained a Patent for making Sea-Water fresh: And the King, before the Grant of this Patent, had the curiosity to go and see Mr. Walcot do it, which was by distilling it in a very large Still; into the Still he put some Ingredient, which was to cure the distilled Water of any noxious Quality: But what it was, he kept a great secret. I suspect that the principal thing was only Distillation, because in all his printed Accounts of it, he purposely avoids the calling it a Still, but calls it a Machine or Engine, and Distilling he calls the working of the Machine, not Distilling."

"The Reverend Dr. Colbatch... who some Years since desired me to attempt, to make Sea-Water wholesome, informs me that he had good Reason to believe that the Ingredient which Mr. Walcot put into Sea-Water, in order to make it wholesome, was some Preparation of by Fire."

"In the Year 1683 Mr. Fitz-gerald, a near Relation of the Famous Robert Boyle Esq; having upon Mr. Boyle's encouragement made a Discovery of a new easy and practicable way of making salt Water fresh... Mr. Walcot asserted before the House of Commons, that Mr. Fitz-gerald's Water was rough, harsh, fiery, corroding and tormenting the Body when constantly drank of. This I suspect was the true Reason why both their Methods of preparing fresh Sea-Water were disused..."

"Mr. Walcot says of his Water, that it was smooth, soft, cooling, and would not decay or putrify in many Years, no not in seven Years... But by its continuing so long in an unputrified State, I suspect there was Spirit of Salt in it, that came over in Distillation: For tho' distiiled common Water is known to keep longer without putrifying, than undistilled Water by reason of its greater purity; yet I found some of the good distiiled Sea-Water to putrify in some time after Distillation, but that which had in it Spirit of Salt never putrified."

"I find that a small Degree of Putrefaction in Water, kills Fish; but if, in order to prevent that Putrefacton, a few Drops of Spirit or Oil of Vitriol be dropped into the Water, then the Fish will live many Days in that Water."

"There is no doubt but it will fully answer your Lordships tender Care and Concern for the Welfare of Navigators, as it will contribute much to their Health, by supplying them, in exchange for a very noxious, with Plenty of fresh Air, that genuine Cordial of Life: For that wonderful Fluid the Air, which, by infinite Combinations with natural Bodies, produces surprizing Effects, as it is on the one Hand when pure, the chief Nourisher and Preserver of the Life of Animals and Vegetables; so, when foul and putrid, it is the great Principle of their Destruction."

"As Sea-farers, that Valuable and Useful Part of Mankind, have many Hardships and Difficulties to contend with, so it is of great Importance to obviate as many of them as possible: And as the noxious Air in Ships has hitherto been one of their greatest Grievances, by making sick and destroying multitudes of them; so the finding a Means to prevent this great Evil, is of vastly more Consequence to Navigation, than the Discovery of the Longitude; as being a Means of saving innumerable more Lives..."

"[It] is evident, not only from considering the Effects of the Engine, which exchanges great Quantities of bad, for good Air; but also from the Event it having been found very salutary by the Swedes who have made the Trial."

"'Tis a good Symptom that we are got upon a right Scent, when it leads not only to the Thing first sought for; but also to many other useful Discoveries, as we see this does."

"We have here an Instance, that the Study of is not a meer trifling Amusement... For it not only delights the Mind, and gives it the most agreeable Entertainment, in seeing in every thing the Wisdom of the great Architect of Nature: But it is also the most likely Means, to make the Gift of kind Providence, this natural World, the more beneficial to us, by teaching us how, both to avoid what is Hurtful, and to pursue what is most Useful and Beneficial to us."

"In the Year 1740, I wrote to Dr. Martin Physician to Lord Cathcart, General of the Forces which lay imbarked at Spithead, for an Expedition in America, to propose (besides the usual sprinkling between Decks with Vinegar) the hanging up very many Cloths dipped in Vinegar, in proper Places between Decks, in order to make the Air more wholesome: And in case an infectious Distemper should be in any Ship, to cure the Infection with the Fumes of burning Brimstone."

"[I]t occurred to me the March following, that large Ventilators would be very serviceable, in making the Air in Ships more wholesome; this I was so fully satisfied of, that I immediately drew up an Account of it; several Copies of wbich were communicated, both by my self and others, to many Persons of Distinction, and Members of the Royal Society: Before whom I laid a large Account of it, which was read in their Presence the May following..."

"November the sixth following, viz. in the Year 1741 Martin Triewald, Captain of Mechanicks and Military Architect to the King of Sweden, and Fellow of the Royal Society at London, in a Letter to M.D. and Secretary of the Royal Society, says, that "this Spring he had invented a Machine, for the Use of his Majesty's Men of War, which went to block up Petersburgh, in order to draw out the bad Air from under their Decks, the least of which does exhaust 36172 cubick Feet of Air in an Hour,"..."

"It were a very extraordinary Circumstance that two Persons at so great a Distance from each other, without getting a Hint of it one from the other, should happen to hit on inventing a like very useful Engine."

"For this Engine [] had a Privilege for Life granted him by the King and Senate of Sweden, dated the 20th October 1741..."

"A Translation of which ingenious Treatise, was communicated to me by Dr. Mortimer; in which he says, "In Hospitals and Barracks for the Sick, this Machine is placed in the , from whence two or three Pipes go down, some Inches thro' the Ceiling, into each Room where the Sick lie; and thus draw out all the unwholesome Air and Stench, which does more harm than any Physick can repair. And at the same time, has this accidental Benefit, That those who begin to mend, may give themselves a proper Exercise, in working the Machine: Only they ought to take care to keep all the Garret-Windows open, while the Machine is a going. In Men of War and Hospital-Ships, this Machine is placed on the upper Deck, directly over the great other Hatch: And then the Pipe, which goes down between the Decks, draws out the unwholesome Air; which is instantly supplied by fresh."

"This Treatise, he says, was read before the Royal Academy of Sweden the third day of April 1742. ...This was eleven Months after mine was laid before the Royal Society."

"And in his Letter to Baron Wasenberg, Envoy from the King of Sweden, dated the 22d of April 1743... he says, "that every Swedish Man of War, and Hospital Ship, was last Year furnished with one of my Engines; which had not been done, in case so they had not experienced the Benefit of the same, the Campaign so before that." So that a Trial was made with these Ventilators in the Year 1741, which proved a very sickly Summer in the Swedish Fleet, except only in the Ship or Ships, which were refreshed by Ventilators: A strong Instance of their great Usefulness; which induced the Swedes to put them into every Man of War and Hospital-Ship, the rear following."

"And Mr. Triewald further says, that in the Summer of the Year 1742, be bad sent one of his Engines, calculated for a Sixty Gun Man of War, to France; which being approved of by the Royal Academy of Sciences at Paris, the King of France has ordered all the Men of War to be furnished with the like Ventilators."

"Being informed, while this Book was printing, that it was said that M.D. F.R.S. had long since made a like Proposal, for sweetning the Air of Ships, in a Treatise called Aëro-Chalinos, or a Register for the Air, printed in the Year 1677... In which Book is the following Proposal, viz. In order to have the Benefit of Change of Air, to another Country or Climate, almost at any Season, and that without going out of the House; he would have a Room, which he calls an Air-Chamber, to be built... Air-tight every where; with a very large Pair of Organ-Bellows to be placed in the Room; to or from which, Air is to be conveyed through the Wall, by a Copper Pipe; with Valves to open inward or outward as Occasion shall require. With these Bellows, the Air in the Room is either to be condensed and made heavier, by forcing Air in, or lighter, by conveying Air out of the Room."

"He proposes by this means to cure intermitting Fevers, by having the Air in the Room rarefied in the cold Fit, and condensed in the hot Fit; during the whole time of which, the Patient is to continue therein: And recommends the use of it, among other Distempers, to cure the Stone and the Pox."

"He proposes also to prevent Sea-Sickness thereby, by having a Man thus shut up in a close Cabin in a compressed Air: This, I suppose, has led some to say, that this and my Proposal are the same. But bow wide is their Difference! My Ventilators are intended to promote a free Perspiration and Breathing, by conveying great Quantities of fresh Air into Ships, in exchange for very bad Air. On the contrary, Dr. Henshaw's Conetrivance would make a good Air, by confining it, very bad, and thereby retard Perspiration, and incommode the Breathing, and so cause, instead of preventing, Sickness... Besides, the Make of my Ventilators is very different from that of Organ-Bellows."

"As these Ventilators are like to prove of great Benefit to Mankind, in many other Respects than are here mentioned, or can as yet be thought of; so it will be of great use, if those who shall have made farther Improvements, will... communicate them; as also an Account of the Difficulties or Success they have met with in putting the Things here proposed in execution."

"As the celebrated Tar-water, recommended by the worthy and learned Bishop Berkeley, is said to be taken with great Benefit by some, and Detriment by others; I thought it might probably be of use to inquire whether any, or what Quantity of Tar, there was in Tar-water, made with different kinds of Tar, different Degrees of stirring, and in different Ways of making it. A short Account of which I shall give, without interesting myself, either in Favour or Disfavour of a Medicine that is under the Inspection of the proper Judges, as well as of all the rest of the World."

"Upon Inquiry from knowing Persons, I find that Norway or Swedish Tar, which is dark, thick and clear... is accounted the best for the general Uses... But that the Tar which is made of the Tops of -Trees... having lain long dead... after having either fallen... or being killed by the draining off their Sap... (These Tops are commonly called Light-wood, the poorer People making use of them instead of Candles:) This Tar being burned in a very strong Fire of such dry Wood, is of a very caustick, corroding Nature, so as to be hurtful to Ropes, &c. for which reason it is not used in the Royal Navy. But the American Tar, which is made of green Fir-Trees, with a less degree of Fire, is esteemed good, and is called green Tar..."

"Having procured some Norway or Swedish Tar which was thirty Years old... I, according to the Bishop's Prescription, made Tar-water in the proportion of a Gallon of Water to a Quart of Tar, stirring it four Minutes: I then took a Pint of this Tar-water, and evaporated it away in a , cut to a wide Orifice... and weighed."

"When Tar-waters of different Degrees of Strength were put into Florence Flasks, with other inverted Flasks fixed on them, and all were placed in the same Vessel of hot Water; on breaking the upper Flasks, the volatile acid Spirit could very sensibly be tasted, especially that of the stronger Tar-water; which shows that these Waters are impregnated therewith: and which when distilled from Turpentine, Dr. Boerhaave in his Chemistry says, is the best vegetable Acid that is known."

"This Acid in Tar-water will curdle Milk; yet Turpentine-water will not... which shows that Tar is considerably acidulated, by the action of Fire in making."

"We have seen in the Course of these Experiments, the Quantity of Tar that there is in Tar-Water; and the great Difference of that Quantity, made with different kinds of Tar, and different Degrees of Stirring. Now, since, notwithstanding these Quantities of Tar, and the additional more subtile volatile Oil, which flies off in Evaporation, it has yet undoubtedly proved an efficacious Remedy in many Cases and Instances; it may hence be reasonably concluded, that the Medicinal Virtue of the Water does not reside solely in the Acid, but partly also in the unctuous oily Parts, which are so temper'd by the Acid, as in some Cases to prevent their heating too much."

"But whereas in some Cases, it is observed by Physicians to be too inflammatory, it is probable, that heating Quality, may in some Degree be abated, by making Tar-Water with the Strainer... without Stirring; thereby to divest the Water of a good Quantity of its grosser, tarrish Particles, and yet retain whatever Powers it may have to do good."

"It is hoped, that the Light given by these Researches, may be of use in skilful Hands, for regulating and adapting the due Proportions of the acid, and the oily Principles, to different Cases and Constitutions. This is the proper Province of the Physician, which I am no ways qualified to meddle in."

"Man, not contented with the Liquors, which his bountiful Creator intending for his Comfort, has wisely tempered with such a due Proportion of Strength, as would (if taken in Moderation,) make his Heart glad, has unhappily found Means to extract, from what God provided for his Refreshment, a most intoxicating and baneful Spirit, to which, in a great measure, is owing the remarkable Increase of Drunkenness of late Years; which Vice reigns to a most enormous Degree, among the habitual Drinkers of Gin, Brandy, and other Distilled Liquors; which are found to be most pernicious and destructive. For at the same shat they coagulate and thicken the Blood, they also contract and narrow the Blood-Vesels; which has, in fact, been found to be true, by Experiments I have purposely made with Brandy, on the Blood and Blood-Vesels of Animals."

"Whence we may evidently see the Reason why those Liquors do so frequently cause those Obstructions and Stoppages in the Liver; which occasion the Jaundice, Dropsy, and many other fatal Diseases."

"It is in like manner also that they destroy and burn up the Lungs. Hence also it is, that by frequently contracting and shrivelling, and then soon after relaxing, they weaken and wear out the Substance and Coats of the Stomach, on which they more immediately prey, every time they are drank."

"Hence likewise it is, that these spirituous Liquors rarely fail to destroy the Appetite and Digestion of those, who habituate themselves to them; for by drying up, and spoiling the Nerves, they make them insensible; they destroy also many of the very fine Blood Vessels, especially where their Fibres are most tender, as in the Brain; by which means, the Memory and intellectual Faculties are ruined: Nay, by inflaming the Blood, and disordering the Blood-Vessels and Nerves, they vitiate and deprave the Natural Temper."

"Could anything increase the pleasure I have in a literary intercourse with you, it would be to find that it answered your end in promoting the publick good. ... It does honour to those noble and other worthy personages that join you in acts of such extensive humanity as the introduction of ventilators into hospitals, prisons, ships of war, and transports, &c. as they must necessarily render the miseries of the first more supportable, and the close and constant confinement of the others less prejudicial and fatal to their health and life. It is to be lamented, that they are not more generally made use of... Those of your invention which I had were of singular service to us; they kept the inside of the ship cool, sweet, dry, and healthy: The number of slaves which I buried was very inconsiderable, and not one white man of our crew (which was thirty four) during a voyage of fifteen months; an instance very uncommon. The 340 negroes were very sensible of the benefits of a constant ventilation, and were always displeased when it was omitted. Even the exercise had an advantage not to be despised among people so much confined. ...Could I but see the immoderate use of spirituous liquors less general, and the benefit of ventilators more known and experienced, I might then hope to see mankind better and happier."

"The following Character of the late Dr. Hales, may he relied upon in every particular, and it is to he regretted that we have not more particulars concerning his useful Life from the same hand. On Sunday the 4th instant [1761], died, at his parsonage-house at Tedington, universally lamented, in the 83rd year of his age, the Rev. Dr. Stephen Hales, F.R.S., member of the royal academy of sciences at Paris and clerk of the closet to her Royal Highness the Princess Dowager of Wales. If any man might ever be said to have devoted his whole life to the public, to all mankind, it was Dr. Hales. He possessed a native innocence and simplicity of manners, which the characters of other men, and the customs of the world, could never alter; and though he often met with many unworthy objects of his kind and charitable offices, yet they never once lessened his natural and unwearied disposition of doing good and relieving distress. His temper, as well as the powers of his understanding, were happily fitted for the improvement of natural philosophy, possessing, as he did, in an uncommon degree, that industry and patient thinking, which Sir Isaac Newton used modestly to declare, was his own only secret by which he was enabled so fortunately to trace the wonderful analysis of nature. Dr. Hales began his inquiries into natural knowledge very early in life, and he continued it uniformly as his darling amusement, being engaged in experiments until within a few weeks of his death. His industry had this farther excellence, that it was always pointed at the general good of his fellow creatures, agreeable to the almost unlimited benevolence of his heart; and being animated with the success of some of his more useful discoveries, his knowledge appeared to everybody near him to feed his mind with a nourishment which gave him, in the decline of his life, and even in its last stages that vigor and serenity of understanding, and clearness of ideas, which so few possess, even [in] the flower of manhood; and which he used often to say, he valued as the most perfect of human pleasures. ...There are two things in his character, which particularly distinguish him from almost every other man; the first was, that his mind was so habitually bent on acquiring knowledge, that, having what he thought an abundant income, he was solicitous to avoid any farther preferment in the church, lest his time and attention might thereby be diverted from his other favorite and useful occupations. The other feature of his character was no less singular: He could look even upon wicked men, and those who did him unkind offices without any emotion of particular indignation; not for want of discernment or sensibility; but he used to consider them only as those experiments which, upon trial, he found could never be applied to any useful purpose, and which he therefore calmly and dispationately laid aside."

"Green s serene retreat, For Philosophic studies meet, Where the good Pastor, Stephen Hales Weigh'd moisture in a pair of scales, To ling'ring death put s and dogs, And stripp'd the skin from living frogs (Nature he loved, her works intent To search, and sometimes, to torment!)"

"[T]he first important conception to be grasped by the student is that of the blood pressure, and the first experiment is designed to demonstrate its existence and to estimate its amount. ...It consists in connecting the of a dog to a long glass tube. Into this tube the blood mounts up and up to a height of five or six feet and then oscillates up or down with each contraction or relaxation of the heart. Such a tube... is called... the "Hales manometer" after its inventor... Dr. Hales."

"During his residence in the college, a period of about twelve years (1696-1708 or 1709), he applied himself with great zeal to the study of natural and experimental philosophy."