Philosophical Transactions/Volume 1/Number 3

Numb. 3



Munday, May 8. 1665.

The Contents.

Some Observations and Experiments upon May-Dew.The Motion of the Second Comet predicted, by the same person, who predicted that of the former.A Relation of the Advice, given by a French Gentleman, touching the Conjunction of the Ocean and the Mediterranean.Of the way of killing Ratle-snakes, used in Virginia.A Relation of Persons kill'd with Subterraneous Damps.Of the Mineral of Liege, yielding both Brimstone, and Vitriol, and the way of extracting them out of it, used at Liege.An Account of Mr. Boyle's Experimental History of Cold.

Some Observations and Experiments upon May-Dew.

THAT ingenious and inquisitive Gentleman, Master Thomas Henshaw, having had occasion to make use of a great quantity of May-dew, did, by several casual Essayes on that Subject, make the following Observations and Tryals, and present them to the Royal Society.

That Dew newly gathered and filtred through a clean Linnen cloth, though it be not very clear, is of a yellowish Colour, somewhat approaching to that of Urine.

That having endevoured to putrefy it by putting several proportions into Glass bodies with blind heads, and setting them in several heats, as of dung, and gentle baths, he quite failed of his intention: for heat, though never so gentle, did rather clarify, and preserve it sweet, though continued for two months together, then cause any putrefaction or reparation of parts.

That exposing of it to the Sun for a whole Summer in Glasses, that hold about two Gallons, with narrow mouths, that might be stopp'd with Cork, the only considerable alteration, he observed to be produced in it, was, that Store of green stuff (such as is seen in Summer in ditches and standing waters) floated on the top, and, in some places, grew to the sides of the Glass.

That putting four or five Gallons of it into a half Tub, as they call it, of Wood, and (training a Canvas over it, to keep out Dust and Insects, and letting it stand in some shady room for three weeks or a month, it did of it self putrefy and stink exceedingly, and let fall to the bottom a black sediment like Mudd,

That, coming often to see, what Alterations appeared in the putrefaction, He observed, that at the beginning, within twenty four hours, a stimy film floated on the top of the water, which after a while falling to the bottom, there came another such film in its place.

That if Dew were put into a long narrow Vessel of Glass, such as formerly were used for Receivers in distilling of Aqua Fortis, the slime would rise to that height, that He could take it off with a Spoon; and when he had put a pretty quantity of it into a drinking Glass, and that it had stood all night, and the water drained from it, if He had turned it out of his hand, it would stand upright in figure of the Glass, in substance like boyled white Starch, though something more transparent, if his memory (saith he) fail him not.

That having once gotten a pretty quantity of this gelly, and put it into a Glass-body and Blind-head, He set it into a gentle Bath, with an intention to have putrefied it, but after a few days He found, the head had not been well luted on, and that some moisture exhaling, the gelly was grown almost dry, and a large Mushrom grown out of it within the Glass. It was of a loose watrish contexture, such an one, as he had seen growing out of rotten wood.

That having several Tubs with good quantity of Dew in them, set to putrefy in the manner above said, and coming to pour out of one of them to make use of it, He found in the water a great bunch, bigger then his first, of those Insects, commonly called Hog lice or Millepedes, tangled together by their long tailes, one of which came out of every one of their bodies, about the bigness of a Horsehair: The Insects did all live and move, after they were taken out.

That emptying another Tub, whereon the Sun, it seems, had used sometimes to shine, and finding, upon the straining it through a clean linnen cloth, two or three spoonfulls of green stuff, though not so thick nor so green as that above mentioned, found in the Glasses purposely exposed to the Sun, He put this green stuff in a Glass, and tyed a paper over it, and coming some dayes after to view it, He found the Glass almost filled with an innumerable Company of small Flyes, almost all wings, such as are usually seen in great Swarms in the Aire in Summer Evenings.

That setting about a Gallon of this Dew (which, he faith, if he misremember not, had been first putrefied and strained) in an open Jarre-Glass with a wide mouth, and leaving it for many weeks standing in a South-window, on which the Sun lay very much, but the Casements were kept close shut; after some time coming to take account of his Dew, He found it very full of little Insects with great Heads and small tapering Bodies, somewhat resembling Tadpoles, but very much less. These, on his approach to the Glass, would sink down to the bottom, as it were to hide themselves, and upon his retreat wriggle themselves up to the top of the water again. Leaving it thus for some time longer, He afterwards found the room very full of Gnats, though the Door and Windows were kept shut. He adds, that He did not at first suspect, that those Gnats had any relation to the Dew, but after finding the Gnats to be multiplied and the little watry Animals to be much lessened in quantity, and finding great numbers of their empty skins floating on the face of his Dew, He thought, he had just reason to perswade himself, the Gnats were by a second Birth produced of those little Animals.

That vapouring away great quantities of his putrefied Dew in Glass Basons, and other Earthen glased Vessels, He did at last obtain, as he remembers, above two pound of Grayish Earth, which when he had washed with more of the same Dew out of all his Basons into one, and vapoured to siccity, lay in leaves one above another, not unlike to some kind of brown Paper, but very friable.

That taking this Earth out, and after he had well ground it on a Marble, and given it a smart Fire, in a coated Retort of Glass, it soon melted and became a Cake in the bottom, when it was cold, and looked as if it had been Salt and Brimstone in a certain proportion melted together; but, as he remembers, was not at all inflammable. This ground again on a Marble, he saith, did turn Spring water of a reddish purple Colour.

That by often calcining and filtring this Earth, He did at last extract about two ounces of a fine small white salt, which, look'd on through a good Microscope, seemed to have Sides and Angles in the same number and figure, as Rochpeeter.

The Motion of the Second Comet predicted by the same Gentleman, who predicted that of the former.

Monsieur Auzout, the same Person, that not long since communicated to the World his Ephemerides touching the course of the former Comet, and recommended several Copies of them to the Royal Society, to compare their Observations with his Account, and thereby, either to verifie his Predictions, or to shew, wherein they differ, hath lately sent another Ephemerides concerning the Motion of the Second Comet, to the same end, that invited him to send the other.

In that Tract he observes, first in General that this second Comet is contrary to the precedent, almost in all particulars: seeing that the former moved very swift, this, pretty slow; that, against the Order of the signs from East to West, this, following them, from West to East: that, from South to North, this, from North to South, as far as it hath been hitherto, that we hear off, observed: that, on the side opposite to the Sun, this, on the same side: that, having been in its Perigee at the time of its Opposition, this, having been there, out of the time of its Conjunction: where he taketh also notice, that this Comet differs in brightness from the other, as well in its Body, which is far more vivid and distinct, as in its Train, whose splendor is much greater, since it may be seen even with great Telescopes, which were useless in the former, by reason of its dimness. After this he descends to particulars, and informs us, that he began to observe this Comet April the second, and continued for some days following, and that as soon as he had made three or four Observations, he resolved to try again an Ephemerides; but that, having no instruments exact enough, and the Comet being in a place, destitute of Stars, and subject to Refractions, he feared to venture too much upon Observations so neer one another, since in such matters a perfect exactness is necessary, and wished to see some precedent Observations to direct him: which having obtained, he thereby verified what he had begun, and resolved to carry on his intended Ephemerides, especially being urged by his Friends, and engaged by his former undertaking, that so it might not be thought a meer hazard, that made him hit in the former; as also, that he might try, whether his Method would succeed as well in slower, as in swifter Comets, and in those, that are neer the Sun; as in such as are opposite thereunto, to the end, that men might be advertised of the determination of its use, if it could not serve but in certain particular Cases.

He relateth therefore, that he had finish'd this New Ephemerides April the sixth, and put it presently to the Press; in doing of which, he hopes, he hath not disobliged the Publick: seeing that, though we should loose the sight of this Star within a few days, by reason of its approach to the Sun, yet having found, that it is always to rise before the Sun, and that we may again see it better, when it shall rise betimes, towards the end of May, and in the beginning of June, if the clearness of the Day-break hinder us not; he thought it worth the while to try, whether the truth of this Ephemerides could be proved.

He affirms then, that the Line described by this Star resembles hitherto a Great Circle, as it is found in all other Comets in the midst of their Course. He finds the said Circle inclined to the Ecliptique about 26.d. 30′. and the Nodes, where it cuts it, towards the beginning of Gemini and Sagittary: that it declines from the Equator about 26.d. and cuts it towards the 11.d. and consequently, that its greatest Latitude hath been towards Pisces, where it must have been March 24. and its greatest Declination, towards the 25. d., of the Equator, where it was to have been April 11.

He puts it in its Perigee March 27. about three of the Clock in the Afternoon, when it was about the 15. degrees of Pisces, a little more Westerly then Marchab, or the Wing of Pegasus, and that it was to be in Conjunction with the Sun, April 9. Where yet he noteth, that according to another Calculation, the Perigee was March 27. more towards Night, so that the Comet advances a little more towards the East, and retards towards the West; which not being very sensible in the first days, differs more about the end, and in the beginning; which he leaves to Observation.

He calculateth, that the greatest Motion it could make in one day, hath been 4. d. and 8′. or 9′; in one hour, about 10′. and 25″. so that its Diurnal Motion is to its left distance from the Earth a little more than as 1. to 14. and its Hourly Motion, as 1. to 330.

He wonders, that it hath not been seen sooner; the first Observations that he hath seen, but made by others, being of March 17. Whereas he finds, that it might have been seen since January, at least in the Months of February and March, when it rose at 2 of the Clock and before: because it is very likely, that, considering its bigness and brightness, when it was towards its Perigee, it was visible, since that towards the end of February it was not three times as much remote from the Earth, than when it was in its Perigee, and that towards the end of January it was not five times as much.

In the interim, saith he, the other Comet could be seen with the naked eye until January 31. when it was more than ten times further remote, than in its Perigee, although it was not by far so bright, nor its streamer shining as this hath appeared.

He wishes, that all the changes that shall fall out in this Comet, might be exactly observ'd; because of its not being swift, and the Motion of the Earth very sensible, unless the Comet be extreamely remote, we should find much more light from this, than the former Star, about the Grand Question, whether the Earth moves or not: this Author having all along entertained himself with the hopes, that the Motion of Comets would evince, whether the Earth did move or not; and this very Comet seemed to him to have by design appeared for that end, if it had had more Latitude, and that consequently we might have seen it before Day-break. He wishes also, that, if possible, it may be accurately observed, whether it will not a little decline from its great Circle towards the South; Judging, that some important truth may be thence deduced, as well as if its motion retarded more, than the place of its Perigee (which will be more exactly known when all the passed Observations shall have been obtained) and its greatest Motion doe require.

He fears only, that it being then to rise at Break of Day, exact Observations cannot be made of it: but he would, at least have it sought with Telescopes, his Ephemerides directing whereabout it is to be.

April 10. it was to be over against the point of the Triangle, and from thence more Southerly by more than two degrees; and April 11. over against the bright Star of Aries: April 17. over against the Stars of the Fly, a little more Southerly, and May 4, it is to be over against the Pleiades, and about the fourth or fifth of the same Month, it is to be once more in Conjunction with the Sun; after which time, the Sun will move from it Eastward, and leave it towards the West; which will enable us to see it again at a better hour, provided the cleerness of the Day-break be no impediment to us; He addeth, that this Star must have been the third time in Conjunction with the Sun, about the time when it first began to appear: and foresees, that from all these particulars many considerable consequences may be deduced.

It will cut the Ecliptick about the end of July, new Style, a little more Eastwards than the Eye of Taurus: at which time there will be no seeing of it, except it be with a Telescope.

It will be towards the End of April, new style, twice as far distant as it was in its Perigee, thrice as far, May the fourth, four times, May the eighteenth, and five times, June the first, &c.

He would not have Men surprised, that there have been two Comets within so short a time; seeing, saith he, there were four, at least, three, in the Year 1618. and in other Years there have been two and more at the same time. What he adds about their signification, we leave to Astrologers to dispute it with him. He concludeth with asking pardon, if he have committed mistakes, which he hopeth he shall obtain the sooner, because of the small time he hath had for these calculations: and he wishes that he could have made all the Observations himself, seeing that it is easie to fail, when one must trust to the Observations of others, whereof we know not the exactness: where he instanceth, that, according to his Observations, the way of the Comet should go neerer the Ecliptick than he hath marked it, even without having any great regard to the Refractions: but since he would subject himself to others, he hath made it pass a little higher, which, he saith, was almost insensibly so, in those few days that he was observing and writing, but that this may perhaps become sensible hereafter: which if it be so, he affirms that it will cut the Ecliptick and Equator sooner, than he hath marked it, &c. However, he thinks it convenient, to have given forehand a common Notion of what will become of a Comet, to prepare men for all the Changes that may fall out concerning it: which he affirms he hath endeavoured to do; the rest being easie to correct, as soon as any good Observations, somewhat distant, have been obtained, considering, that there need but two very exact ones, a little distant when the Star is not swift, to trace its Way; although there must be at least three, to find out all the rest. But, then would he have it considered, that although his Method should be very exact. if there be not at hand Instruments big enough, and Globes good enough to trust to, nothing can be done perfectly in these kind of Predictions.

A Relation of the advice given by Monsieur Petit, Intendant of the Fortifications of Normandy, touching the Conjunction of the Ocean and Mediterranean.

This Intelligent Gentleman, Monsieur Petit, having been consulted with, touching the Conjunction of the Ocean and Mediterranean, delivers first the Proposition, and then giveth his thoughts upon it.

The Proposition is, That there being about two Leagues below Castres in Languedoc a Rivolet, called Sor, passing to Revel, there may by the means thereof be made a Communication of the two Seas, by joyning the Waters of this Rivolet by a Channel (to be kept full all the year long) With those of St. Papoul, and others, which fall into Fresqueil (another small River) that runs into the Aude below Carcassone, and go together to Narbonne, situated upon the Meediterranean.

Having given the Proposition, he adds some particulars, to illustrate the same, before he declares his judgment upon it. For he relateth, that there is but one way, after the division of the Waters, to pass to the Mediterranean, which is by a Rivolet, called Fresqueil, that is conjoyn'd with the Aude: But, to pass to the Ocean, there are three; One, by Riege, entring into the Garome above Tholouse; the other, by Lers, passing on the side, and below the same Town; and the third, by Sor, falling into the River Agoust under Castres, afterwards into the Tarne, and thence to Montauban, and lastly into the Garonne. And that, to compass this design, all these Rivers and Rivolets are first to he made Navigable unto their Sluces; that of Aude and Fresqueil for the Mediterranean, and one of the others, such as shall be chosen, for the Ocean. He addeth, that, as to the several Ways passing to the Ocean, all of them commended as proper and convenient, and the three Countries concerned therein, speaking every one for their advantage: Those of Castres and Montauban, are for the River Agoust; those of Tholouse, for Riege; and the rest, for Lers.

Now concerning his Opinion upon this Proposition, he thinks, that all that hath been represented touching this matter, can signify very little seeing that the main thing is wanting, which is the assurance, and certain and positive mensuration of the height and quantity of the Waters, necessary to fall into both the Channels of the Aude and Garonne; that there must be plenty of that, to furnish at all times and alwaies the highest and first Sluces, since what once issues thence, doth never cuter again into them; and after some Boats are passed, if there should not be a sufficient supply for those that come after, either to go up, or to go down, all would stand dry, and Merchants and their Commodities would stay long enough expecting the supply of Rains, to their great detriment. He concludeth therefore, that no knowing and discreet Person is able, in matters of this nature, to give a positive answer, without having before him a large and exact Topographical Map of those places, and of the sources of all the Rivolets, that are to supply the Water to the Head of the pretended Channel, together with a full account of the survey and mensuration of all the places, through which it is to pass; of the Nature of the Ground, whether it be stony, sandy, rocky, &c. of the exact level of all the places, where it is to be made, and of the several risings and depressions thereof; to be assured that the Water may be conveyed to the greatest rising, and to the highest Sluce; and lastly, of the quantity, that may be had at high, middle, and low Water, to have enough for all times; that all these things being first made out, 'tis then time enough to judge of the possibility of the thing, and to calculate the Charges necessary for Execution.

This Artist having thus prudently waved this Proposition, diverts himself with reflecting upon several others of the like nature, among which he insists chiefly upon two, whereof one is that so much celebrated in Egypt,; the other, of Germany. And he is of Opinion, that the most important of all is that, of conjoining the Red sea by the Nile with the Mediterranean, which he looks upon as the most excellent convenience to go into the East-Indies without doubling the Cape of Good-Hope; and yet it could not be executed by those great Kings of Egypt, that raised so many stupendious Pyramids; although in his Opinion the reasons alleged by Historians to justifie them for having abandoned that undertaking, are of no validity, and that the Red Sea cannot be, as they feared, higher than the Nile, and therefore not indanger the inundation of Egypt.

The other Proposition was made to Charles Magne, Anno 793. for joyning the Euxine Sea and the Ocean together, by a Channel, which was begun for that end, and designed to be 2000. paces long, and 100 paces broad, betwixt the River Altmull, falling into the Danube above Ratisbone, and the River Rott, passing at Nurenberg, and thence running into the Main, and so into the Rhine. But yet this also proved abortive, though there was great appearance of success at first.

Of a Way[errata 1] of killing Ratle-Snakes.

There being not long since occasion given at a meeting of the Royal Society to discourse of Ratle-Snakes, that worthy and inquisitive Gentleman, Captain Silas Taylor, related the manner, how they were killed in Virginia, which he afterwards was pleased to give in writing, attested by two credible persons in whose presence it was done; which is, as follows.

The Wild Penny-royal or Ditany of Virginia, groweth streight up about one foot high, with the leaves like Penny royal, with little blue tufts at the joyning of the branches to the Plant, the colour of the Leaves being a reddish green, but the Water distilled, of the colour of Brandy, of a fair Yellow: the Leaves of it bruised are very hot and biting upon the Tongue: and of these, so bruised, they took some, and having tyed them in the cleft of a long stick, they held them to the Nose of the Ratle-Snake, who by turning and wriggling laboured as much as she could to avoid it; but she was killed with it, in less than half an hour's time, and, as was supposed, by the scent thereof; which was done Anno 1657, in the Month of July, at which season, they repute those creatures to be in the greatest vigour for their poison.

Captain Taylor did affirm, that, in those places, where the Wild Penny-Royal or Dittany grows, no Ratle-Snakes are observed to come.[errata 2]

A Relation of Persons killed with subterraneous Damps.

This Relation was likewise made to the Royal Society, by that Eminent Virtuoso Sir R. Moray, who was pleased, upon their desire, to give it them in writing; as followeth,

In a Coal-pit, belonging to the Lord Sinclair in Scotland, where the Coal is some 18 or 20 foot thick, and antiently wasted to a great depth: The Colliers, some Weeks agoe, having wrought as deep as they could, and being to remove into new Rooms (as they call them) did, by taking off, as they retired, part of the Coal that was left as Pillars to support the Roof and Earth over it, so much weaken them, that within a short space, after they were gone out of the Pitt, the Pillars falling, the Earth above them filled up the whole Space, where the Colliers had lately wrought, with its ruins. The Colliers being here-by out of work, some of them adventured to work upon old remains of Walls, so near the old wastes, that striking through the slender partition of the Coal wall, that separated between them and the place, where they used to work, they quickly perceived their Errour, and fearing to be stifled by the bad Air, that they knew, possessed these old wastes, in regard not onely of the Damps, which such wastes do usually afford, but because there having for many years been a Fire in those wastes, that filled them with stifling fumes and vapours, retired immediately and saved themselves from the eruptions of the Damp. But next day some seven or eight of them came no sooner so far down the staires that led them to the place, where they had been the day before, as they intended, but upon their stepping into the place, where the Air was infected, they fell down dead, as if they had been shot: And there being amongst them one, whose Wife was informed he was stifled in that place, she went down so far without inconvenience, that seeing her Husband near her, ventured to go to him, but being choaked by the Damp, as soon as the came near him, she fell down dead by him.

This Story Sir R. Moray affirmed to have received from the Earl of Weymes, Brother in Law to the Lord Sinclair, as it was written to him from Scotland.

Of the Mineral of Liege, yielding both Brimstone and Vitriol, and the way of extacting them out of it, used at Liege.

The Account of this Mineral, and of the way of extracting both Brimstone and Vitriol out of it, was procured from Liege, by the lately mentioned Sir Robert Moray, and by him communicated to the Royal Society, as follows.

The Mineral, out of which Brimstone and Vitriol are extracted, is one and the same, not much unlike Lead-ore, having also oft times much Lead mingled with it, which is separated from it by picking it our of the rest. The Mines resemble our English Coal-Mines, dugg according to the depth of the Mineral, 15, 20, or more fathoms, as the Vein leads the Workmen, or the subterranean waters will give them leave, which in Summer so overflow the Mines, that the upper waters, by reason of the drought, not sufficing to make the Pumps goe, the Work ceases.

To make Brimstone, they break the Stone or Ore into small pieces, which they put into Crucibles made of Earth, five foot long, square and pyramid wise. The Entry is near a foot square. These Crucibles are laid sloaping, eight undermost, and seven above them, as it were betwixt them, that the Fire may come at them all, each having its particular Furnace or Oven. The Brimstone being dissolved by the violence of the hear, drops out at the small end of the Crucible, and falls into a Leaden-Trough or Receptacle, common to all the said Crucibles, through which there runs a continual Rivolet of cold water, conveyed thither by Pipes for the cooling of the dissolved Sulphur, which is ordinarily four hours in melting. This done, the Ashes are drawn out with a crooked Iron, and being put into an Iron Wheel-barrow, are carried out of the Hutt, and being laid in a heap, are covered with other elixed or drained Ashes, the better to keep them warm; which is reiterated, as long as they make Brimstone.

To make Coperas or Vitriol, they take a quantity of the said Ashes, and throwing them into a square planked pit in the Earth, some four foot deep, and eight foot square, they cover the same with ordinary water, and let it lye twenty four hours, or untill an Egge will swim upon the liquor, which is a sign, that it is strong enough. When they will boyl this, they let it run through Pipes into the Kettles, adding to it half as much Mother-water, which is that water, that remains after boyling of the hardned Coperas. The Kettles are made of Lead, 41/2 foot high, 6 foot long, and 3 foot broad, standing upon thick Iron Barrs or Grates. In these the Liquor is boyled with a strong Coal-fire, twenty four hours or more, according to the strength or weakness of the Lee or Water. When it is come to a just consistence, the fire is taken away, and the boyled liquor suffered to cool somewhat, and then it is tapp'd out of the said Kettles, through holes beneath in the sides of them, and conveyed through wooden Conduits into several Receptacles, three foot deep and four foot long (made and ranged not unlike our Tan-pits) where it remains fourteen or fifteen dayes, or so long till the Coperas separate it self from the water, and becomes icy and hard. The remaining water is the above-mentioned Mother-water; and the elixed or drained Ashes are the Dreggs, or Caput mortuum, which the Lee, whereof the Vitriol is made, leaves behind it in the planked Pitts.

A further Account of Mr. Boyle's Experimental History of Cold.

In the first Papers of these Philosophical Transactions, some promise was made of a fuller account, to be given by the next, of the Experimental History of Cold, composed by the Honourable Mr. Robert Boyle; it being then supposed, that this History would have been altogether printed off at the time of publishing the Second Papers of these Transactions; but the Press, employed upon this Treatise, having been retarded somewhat longer than was ghessed, the said promise could not be performed before this time: wherein it now concerns the inquiring World to take notice, that this subject, as it hath hitherto bin almost totally neglected, so it is now, by this Exceellent Author, in such a manner handled, and improved by near Two hundred choice Experiments and Observations, that certainly the Curious and Intelligent Reader will in the perusal thereof find cause to admire both the Fertility of a Subject, seemingly so barren, and the Author's Abilities of improving the same to so high a Degree.

But to take a short view short view of the particulars of this History, and thereby to give occasion to Philosophical men, to take this Subject more into their consideration, than hitherto hath been done; the ingenious Readers will here see,

1, That not only all sorts of Acid and Alcalizate Salts, and Spirits, even Spirit of Wine; but also Sugar, and Sugar of Lead mixed with Snow, are capable of freezing other Bodies, and upon what account they are so.

2, That among the Substances capable of being frozen, there are not only all gross sorts of Saline Bodies, but such also as are freed from their grosser parts, not excepting Spirit of Urine, the Lixivium of Pot-ashes, nor Oyl of Tartar, per deliquium, it self.

3, That many very spirituous liquors, freed from their aqueous parts, cannot be brought to freeze, neither naturally, nor artificially: And here is occasionally mentioned a way of keeping Moats unpassable in very cold Countries, recorded by Olaus Magnus.

4, What are the wayes proper to estimate the greater or lesser Coldness of Bodies; and by what means we can measure the intensness of Cold produced by Art, beyond that, which Nature needs to employ for the freezing of Water; as also, in what proportion water of a moderate degree of Coldness will be made to shrink by Snow and Salt, before it begin by Congelation to expand it self; and then, how to measure by the differing Weight and Density of the same portion of Water, what change was produced in it, betwixt the hottest time of Summer, and first glaciating degree of Cold, and then the highest, which our Author could produce by Art: Where an Inquiry is annex'd, whether the making of these kind of Tryals with the waters of the particular Rivers and Seas, men are to sail on, may afford any useful estimate, whether or not, and how much, ships afford those waters be safely loaden more in Winter, than in Summer. To which is added the way of making exact Discoveries of the differing degrees of Coldness in differing Regions, by such Thermometers, as are not subject to the alterations of the Atmosphere's gravitation, nor to be frozen.

5. Whether in Cold, the diffusion from Cold Bodies be made more strongly downwards, contrary to that of Hot Bodies: Where is delivered a way of freezing Liquors without danger of breaking the Vessel, by making them begin to freeze at the bottom, not the top.

6. Whether that Tradition be true, that if frozen Apples or Eggs be thaw'd neer the Fire, they will be thereby spoil'd, but if immersed in cold water, the Internal Cold will be drawn out, as is supposed, by the External Cold; and the frozen Bodies will be harmlesly thawed? Item, Whether Iron, or other Metals, Glass, Stone, Cheese, &c. expos'd to the freezing Air, or kept in Snow or Salt, upon the immersing them in Water will produce any Ice? Item, What use may be made of what happens in the different waies of thawing Eggs and Apples, by applying the Observation to other Bodies, and even to Men, dangerously nipp'd by excessive Cold. Where is added not only a memorable Relation, how the whole Body of a Man was succesfully thawed and cased all over with Ice, by being handled, as frozen Eggs and Apples are; but also the Luciferousness of such Experiments as these: and likewise, what the effects of Cold may be, as to the Conservation or Destruction of the Textures of Bodies: and in particular, how Meat and Drink may be kept good, in very Cold Countries, by keeping it under Water, without glaciation? as also, how in extreme Cold Countries, the Bodies of Dead Men and other Animals may be preserved very many years entire and unputrefied? And yet, how such Bodies, when unfrozen, will appear quite vitiated by the excessive Cold? Where it is further inquired into, whether some Plants, and other Medicinal things, that have specifique Vertues, will loose them by being thoroughly congealed and (several wayes) thawed? And also, whether frozen and thawed Harts-horn will yield the same quantity and strength of Salt and saline Spirit, as when unfrozen? Item, Whether the Electrical faculty of Amber, and the Attractive or Directive Virtue of Loadstones will be either impaired, or any wayes altered by intense Cold? This Head is concluded by some considerable remarks touching the operation of Cold upon Bones, Steel, Brass, Wood, Bricks.

7, What Bodies are expanded by being frozen, and how that expansion is evinced? And whether it is caused by the intrusion of Air? As also, whether, what is contained in icy bubbles, is true and Springy Air, or not.

8, What Bodies they are, that are contracted by Cold; and how that Contraction is evinced? Where 'tis inquired, whether Chymical Oyles will, by Congelation, be, like expressed Oyles, contracted, or, like aqueous Liquors, expanded?

9, What are the wayes of Measuring the Quantity of the Expansion and Contraction of Liquors by Cold? And how the Author's account of this matter agrees with what Navigators into cold Climats, mention from experience, touching pieces of Ice as high as the Masts of their Ships, and yet the Depth of these pieces seems not at all answerable to what it may be supposed to be.

10, How strong the Expansion of freezing water is? Where are enumerated the several sorts of Vessels, which being filled with water, and exposed to the cold Air, do burst; and where also the weight is expressed, that will be removed by the expansive force of Freezing? Whereunto an Inquiry is subjoined, whence the prodigious force, observed in water, expanded by Glaciation, should proceed? And whether this Phænomenon may be solved, either by the Cartesian, or Epicurean Hypothesis?

11. What is the Sphere of Activity of Cold, or the Space, to whose extremities every way the Action of a cold Body is able to reach: where the difficulty of determining these limits, together with the causes thereof; being with much circumspection mentioned, it is observed, that the Sphere of Activity of Cold is exceeding narrow, not onely in comparison of that of Heat in Fire, but in comparison of, as it were, the Atmosphere of many odorous Bodies; and even in comparison of the Sphere of Activity of the more vigorous Loadstones, insomuch, that the Author hath doubted, whether the Sense could discern a Cold Body, otherwise then by immediate Contract. Where several Experiments are delivered for the examining of this matter, together with a curious relation of the way used in Persia, though a very hot Climate, to furnish their Conservatories with solid pieces of Ice of a considerable thickness: To which is added an Observation, how far in Earth and Water the Frost will pierce downwards, and upon what accounts the deepness of the Frost may vary. After which, the care is inculcated, that must be had, in examining, whether Cold may be diffused through all Mediums indefinitely, not to make the Trials with Mediums of two great thickness: where it is made to appear, that Cold is able to operate through Metalline Vessels, which is confirmed by a very pretty Experiment of making Icy Cups to drink in; whereof the way is accurately set down. Then are related the Trials, whether, or how, Cold will be diffused through a Medium, that some would think a Vacuum, and which to others would seem much less disposed to assist the diffusion of Cold, than Common Air it self. After which follows a curious Experiment, shewing whether a Cold Body can operate through a Medium actually hot, and having its heat continually renewed by a fountain of heat.

12, How to estimate the solidity of the Body of Ice, or how strong is the mutual adhesion of its parts? and whether differing Degrees of Cold may not vary the Degree of the compactness of Ice. And our Author having proceeded as far as he was able towards the bringing the strength of Ice to some Estimate by several experiments, he communicateth the information, he could get about this matter among the Descriptions that are given us of Cold Regions: And then he relateth out of Sea-mens Journals, their Observations touching the insipidness of resolved Ice made of Sea-water; and the prodigious bigness of it, extending even to the height of two hundred and fourty Foot above water, and the length of above eight Leagues. To which he adds some promiscuous but very notable Observations concerning Ice, not so readily reducible to the foregoing Heads: videlicet, Of the blew Color of Rocky pieces of Ice; and the horrid noise made by the breaking of Ice, like that of Thunder and Earthquakes, together with a Consideration of the Cause, whence those loud Ruptures may proceed.

13, How Ice and Snow may be made to last long; and what Liquor dissolves Ice sooner than others, and in what proportion of quickness the solutions in the several Liquors are made, where occasion is offered to the Author, to examine, whether Motion will impart a heat to Ice? After which, he relates an Experiment of Heating a Cold Liquor with Ice, made by himself in the presence of a Great and Learned Nobleman, and his Lady, who found the Glass wherein the Liquor was, so hot that they could not endure to hold it in their Hands. Next, it is examined, whether the effects of Cold do continually depend upon the actual presence and influence of the manifest Efficient Causes, as the Light of the Air depends upon the Sun or Fire, or other Luminous Bodies. To this is annexed an Account of the Italian way of making Conservatories of Ice and Snow, as the Author had received it from that Ingenious and Polite Gentleman, Master J. Evelyn.

But want of time prohibiting the accomplishment of the intended account of this Rich Piece: what remains, must be referred to the next Occasion. lt shall only be intimated for a Conclusion, that the Author hath annexed to this Treatise, an Examen of Master Hobs's Doctrine touching Cold; wherein the Grand Cause of Cold and its Effects is assigned to Wind, in so much that 'tis affirmed, that almost any Ventilation and stirring of the Air doth refrigerate.

Printed with Licence, By John Martyn, and James Allestry, Printers to the Royal-Society. 1665.

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