Part 3
The mines of _Mercury_ in _Friuli_, a Territory belonging to the _Venetians_, are about a days Journey and a half distant from _Goritia_ Northwards, at a place call'd _Idria_, scituated in a Valley of the _Julian Alps_. They have been, as I am inform'd, these 160. years in the possession of the Emperor, and all the Inhabitants speak the _Sclavonian_ Tongue. In going thither, we travell'd several hours in the best Wood I ever saw before or since, being very full of _Firrs_, _Oakes_, and _Beeches_, of an extraordinary thickness, straitness, and height. The Town is built, as usually Towns in the _Alps_ are, all of wood, the Church only excepted, and another House wherein the Overseer liveth. When I was there, in _August_ last, the Valley, and the Mountains too, out of which the _Mercury_ was dug, were of as pleasant a verdure, as if it had been in the midst of Spring, which they there attribute to the moistness of the _Mercury_; how truly, I dispute not. That Mine, which we went into, the best and greatest of them all, was dedicated to Saint _Barbara_, as the other Mines are to other Saints, the depth of it was 125. paces, every pace of that Country being, as they inform'd us, more than 5 of our Feet. There are two ways down to it; the shortest perpendicular way is that, whereby they bring up the Mineral in great Buckets, and {22} by which oftentimes some of the workmen come up and down. The other, which is the usual way, is at the beginning not difficult, the descent not being much; the greatest trouble is, that in several places you cannot stand upright: but this holds not long, before you come to descend in earnest by perpendicular Ladders, where the weight of on's body is found very sensible. At the end of each Ladder, there are boards a-cross, where we may breath a little. The Ladders, as we said, are perpendicular, but being imagined produced, do not make one Ladder, but several parallel ones. Being at the bottom, we saw no more than we saw before, only the place, whence the Mineral came. All the way down, and the bottom, where there are several lanes cut out in the Mountain, is lined and propt with great pieces of Firr-trees, as thick as they can be set. They dig the Mineral with Pick-axes, following the veins: 'tis for the most part hard as a stone, but more weighty; of a Liver-colour, or that of _Crocus Metallorum_. I hope shortly to shew you some of it. There is also some soft Earth, in which you plainly see the _Mercury_ in little particles. Besides this, there are oftentimes found in the Mines round stones like Flints, of several bignesses, very like those Globes of Hair, which I have often seen in _England_, taken out of Oxes bellies. There are also several _Marcasites_ and stones, which seem to have specks of Gold in them, but upon tryal they say, they find none in them. These round stones are some of them very ponderous, and well impregnated with _Mercury_; others light, having little or none in them. The manner of getting the _Mercury_ is this: They take of the Earth, brought up in Buckets, and put it into a Sive, whose bottom is made of wires at so great a distance, that you may put your finger betwixt them: 'tis carried to a stream of running water, and wash'd as long as any thing will pass through the Sive. That Earth which passeth not, is laid aside upon another heap: that which passeth, reserved in the hole, G. in Fig. 1. and taken up again by the second Man, and so on, to about ten or twelve sives proportionably less. It often happens in the first hole, where the second Man takes up his {23} Earth, that there is _Mercury_ at the bottom; but towards the farther end, where the Intervals of the wires are less, 'tis found in very great proportion. The Earth laid aside is pounded, and the same operation repeated. The fine small Earth, that remains after this, and out of which they can wash no more _Mercury_, is put into Iron retorts and stopt, because it should not fall into the Receivers, to which they are luted. The fire forces the _Mercury_ into the Receivers: the Officer unluted several of them to shew us; I observed in all of them, that he first poured out perfect _Mercury_, and after that came a black dust, which being wetted with water discover'd it self to be _Mercury_, as the other was. They take the _Caput mortuum_ and pound it, and renew the operation as long as they can get any _Mercury_ out of it.
This is the way of producing the _Mercury_, they call _Ordinary_, which exceeds that, which is got by washing, in a very great proportion, as you will perceive by the account annext. All the _Mercury_ got without the use of Fire, whether by washing, or found in the Mines (for in the digging, some little particles get together, so that in some places you might take up two or three spoonfuls of pure _Mercury_) is call'd by them _Virgin Mercury_, and esteem'd above the rest. I inquir'd of the Officer what vertue that had more, than the other; he told me that making an _Amalgama_ of Gold and _Virgin Mercury_, and putting it to the fire, that _Mercury_ would carry away all the Gold with it, which common _Mercury_ would not do.
The Engins, employed in these Mines, are admirable; the Wheels, the greatest that ever I saw in my life; one would think as great as the matter would bear: all moved by the dead force of the water, brought thither in no chargeable Aqueduct from a Mountain, 3 Miles distant: the water pumpt from the bottom of the Mine by 52 pumps, 26 on a side, is contrived to move other wheels, for several other purposes.
The Labourers work for a _Julio_ a day, which is not above 6 or 7 pence, and indure not long; for, although none stay {24} underground above 6 hours; all of them in time (some later, some sooner) become _paralitick_, and dye _hectick_.
We saw there a man, who had not been in the Mines for above half a year before, so full of _Mercury_, that putting a piece of _Brass_ in his mouth, or rubbing it in his fingers, it immediately became white like Silver: I mean he did the same effect, as if he had rubb'd _Mercury_ upon it, and so paralitick, that he could not with both his hands carry a Glass, half full of Wine, to his mouth without spilling it, though he loved it too well to throw it away.
I have been since informed, that here in _Venice_, those that work on the back-side of Looking-glasses, are also very subject to the _Palsey_. I did not observe, that they had black Teeth; it may be therefore, that we accuse _Mercury_ injustly for spoiling the Teeth, when given in _Venereal_ diseases. I confess, I did not think of it upon the place; but, black Teeth being so very rare in this Country, I think I could not but have markt it, had all theirs been so.
They use exceeding great quantity of Wood, in making and repairing the Engins, and in the Furnaces (whereof there are 16. each of them carrying 24. Retorts;) but principally in the Mines, which need continual reparation, the Fir-trees lasting but a small time under ground. They convey their Wood thus: About four miles from the Mines, on the sides of two mountains, they cut down the Trees, and draw them into the interjacent Valley, higher in the same Valley, so that the Trees, according to the descent of the water lye betwixt it and _Idria_: with vast charges and quantities of Wood they made a Lock or Dam, that suffers not any water to pass; they expect afterwards till there be water enough to float these Trees to _Idria_; for, if there be not a spring, (as generally there is,) Rain, or the melting of the Snow, in a short time, afford so much water, as is ready to run over the Dam, and which (the Flood-gates being open'd) carries all the Trees impetuously to _Idria_, where the Bridge is built very strong, and at very oblique Angles to the stream, on purpose to stop them, and throw them on shore neer the Mines. {25}
Those Mines cost the _Emperour_ heretofore 70000. or 80000. _Florens_ yearly, and yielded less _Mercury_ than at present, although it costs him but 28000. _Florens_ now. You may see what his Imperial Majesty gets by the following account, of what _Mercury_ the Mines of _Idria_ have produced these last three years.
1661. l. Ordinary _Mercury_ 198481 Virgin _Mercury_ 6194 -------- 204675 --------
1662. l. Ordinary _Mercury_ 225066 Virgin _Mercury_ 9612 -------- 234678 --------
1663. l. Ordinary _Mercury_ 244119 Virgin _Mercury_ 11862 -------- 255981 --------
There are alwaies at work 280 persons, according to the relation I received from a very civil person, who informed me also of all the other particulars above mentioned, whose name is _Achatio Kappenjagger_; his Office, _Contra-scrivano per sua Maestà Cesarea in Idria del Mercurio_.
To give some light to this Narrative, take this Diagramme: F. is the water, C. B. a vessel, into which it runs. DG. EH. FI. are streams perpetually issuing from that vessel; D. E. F. three sives, the distance of whose wires at bottom lessen proportionably. G. the place, wherein the Earth, that pass'd through the sive D. is retained; from whence 'tis taken by the second man; and what passes through the sive E. is retained in H. and so of the rest. K. L. M. wast water, which is so much impregnated with _Mercury_, that it cureth Itches and sordid Ulcers. See Fig. 1.
I will trespass a little more upon you, in describing the contrivance of blowing the Fire in the _Brassworks_ of _Tivoli_ neer _Rome_ (it being new to me) where the Water blows the Fire, not by moving the Bellows, (which is common) but by affording the Wind. See Fig. II. Where A. is the {26} River, B. the Fall of it, C. the Tub into which it falls, LG. a Pipe, G. the orifice of the Pipe, or Nose of the Bellows, GK. the Hearth, E. a hole in the Pipe, F. a stopper to that hole, D. a place under ground, by which the water runs away. Stopping the hole E, there is a perpetual strong wind, issuing forth at G: and G. being stopt, the wind comes out so vehemently at E, that it will, I believe, make a Ball play, like that at _Frescati_.
* * * * *
_An Extract of a Letter, containing some Observations, made in the ordering of _Silk-worms_, communicated by that known _Vertuoso_, Mr. _Dudley Palmer_, from the ingenuous Mr. _Edward Digges_._
I herewith offer to your _Society_ a small parcel of my _Virginian_ Silk. What I have observed in the ordering of Silk-worms, contrary to the received opinion, is:
1. That I have kept leaves 24. hours after they are gathered, and flung water upon them to keep them from withering; yet when (without wiping the leaves) I fed the worms, I observed, they did as well as those fresh gathered.
2. I never observed, that the smell of _Tobacco_, or smels that are rank, did any waies annoy the worm.
3. Our country of _Virginia_ is very much subject to Thunders: and it hath thundered exceedingly when I have had worms of all sorts, some newly hatched; some half way in their feeding; others spinning their Silk; yet I found none of them concern'd in the Thunder, but kept to their business, as if there had been no such thing.
4. I have made many bottoms of the Brooms (wherein hundreds of worms spun) of _Holly_; and the prickles were so far from hurting them, that even from those prickles they first began to make their bottoms.
I did hope with this to have given you assurance, that by retarding the hatching of seed, two crops of silk or more {27} might be made in a Summer: but my servants have been remiss in what was ordered, I must crave your patience till next year.
* * * * *
_An account of _Micrographia_, or the _Physiological Descriptions_ of _Minute Bodies_, made by _Magnifying Glasses_._
The Ingenious and knowing Author of this _Treatise_, Mr. _Robert Hook_, considering with himself, of what importance a faithful _History of Nature_ is to the establishing of a solid Systeme of _Natural Philosophy_, and what advantage _Experimental_ and _Mechanical_ knowledge hath over the Philosophy of _discourse_ and _disputation_, and making it, upon that account, his constant business to bring into that vast Treasury what portion he can, hath lately published a Specimen of his abilities in this kind of study, which certainly is very welcome to the Learned and Inquisitive world, both for the _New discoveries_ in _Nature_, and the _New Inventions_ of _Art_.
As to the _former_, the Attentive Reader of this Book will find, that there being hardly any thing so small, as by the help of _Microscopes_, to escape our enquiry, a new visible world is discovered by this means, and the Earth shews quite a new thing to us, so that in every _little particle_ of its matter, we may now behold almost as great a variety of creatures, as we were able before to reckon up in the whole _Universe_ it self. Here our Author maketh it not improbable, but that, by these helps the subtilty of the composition of Bodies, the structure of their parts, the various texture of their matter, the instruments and manner of their inward motions, and all the other appearances of things, may be more fully discovered; whence may emerge many admirable advantages towards the enlargement of the _Active_ and _Mechanick_ part of knowledge, because we may perhaps be enabled to discern the secret {28} workings of _Nature_, almost in the same manner, as we do those that are the productions of _Art_, and are managed by _Wheels_, and _Engines_, and _Springs_, that were devised by Humane wit. To this end, he hath made a very curious _Survey_ of all kinds of bodies, beginning with the _Point of a Needle_, and proceeding to the _Microscopical_ view of the _Edges_ of _Rasors, Fine Lawn, Tabby, Watered Silks, Glass-canes, Glass-drops, Fiery Sparks, Fantastical Colours, Metalline Colours, the Figures of Sand, Gravel in Urine, Diamonds in Flints, Frozen Figures, the Kettering Stone, Charcoal, Wood and other Bodies petrified, the Pores of Cork, and of other substances, Vegetables growing on blighted Leaves, Blew mould and Mushromes, Sponges, and other Fibrous Bodies, Sea-weed, the Surfaces of some Leaves, the stinging points of a Nettle, Cowage, the Beard of a wild Oate, the seed of the Corn-violet, as also of Tyme, Poppy and Purslane._ He continues to describe _Hair, the scales of a Soal, the sting of a Bee, Feathers_ in general, and in particular those of _Peacocks; the feet of Flies; and other Insects; the Wings and Head of a Fly; the Teeth of a Snail; the Eggs of Silk-worms; the Blue Fly; a water Insect; the Tufted Gnat; a White Moth; the Shepheards-spider; the Hunting Spider, the Ant; the wandring Mite; the Crab-like insect, the Book-worm, the Flea, the Louse, Mites, Vine mites._ He concludeth with taking occasion to discourse of two or three very considerable subjects, viz. _The inflexion of the Rays of Lights in the Air; the Fixt stars; the Moon._
In representing these particulars to the Readers view, the Author hath not only given proof of his singular skil in delineating all sorts of Bodies (he having drawn all the _Schemes_ of these 60 _Microscopical_ objects with his own hand) and of his extraordinary care of having them so curiously engraven by the Masters of that Art; but he hath also suggested in the several reflexions, made upon these Objects, such conjectures, as are likely to excite and quicken the Philosophical heads to very noble contemplations. Here are found inquiries concerning the _Propagation of Light_ through {29} differing mediums; concerning _Gravity_, concerning the _Roundness_ of Fruits, stones, and divers artificial bodies; concerning _Springiness_ and _Tenacity_; concerning the _Original_ of _Fountains_; concerning the _dissolution of Bodies into Liquors_; concerning _Filtration_, and the ascent of Juices in Vegetables, and the use of their _Pores_. Here an attempt is made of solving the strange _Phænomena_ of _Glass-drops_; experiments are alleged to prove the _Expansion_ of _Glass_ by heat, and the _Contraction_ of _heated-Glass_ upon cooling; _Des Cartes_ his _Hypothesis of Colours_ is examined: the _cause of Colours_, most likely to the Author, is explained: Reasons are produced, that _Reflection_ is not necessary to produce _colours_, nor a _double refraction_: some considerable _Hypotheses_ are _offered_, for the explication of Light by Motion; for the producing of all colours by Refraction; for reducing all sorts of colours to two only, _Yellow_ and _Blew_; for making the _Air_, a dissolvent of all _Combustible Bodies_: and for the explicating of all the regular figures of _Salt_, where he alleges many notable instances of the _Mathematicks_ of _Nature_, as having even in those things which we account vile, rude & course, shewed abundance of curiosity and excellent _Geometry_ and _Mechanism_. And here he opens a large field for inquiries, and proposeth Models for prosecuting them, 1. By making a full collection of all the differing kinds of _Geometricall_ figur'd bodies; 2. By getting with them an exact History of their places where they are generated or found: 3. By making store of Tryals in Dissolutions and Coagulations of several Crystallizing Salts: 4. By making trials on metalls, Minerals and Stones, by dissolving them in severall _Menstruums_, and Crystallizing them, to see what Figures will arise from those several compositums: 5. By compounding & coagulating several Salts together into the same mass, to observe the Figure of that product: 6. By inquiring the closenes or rarity of the texture of those bodys by examining their gravity, and their refraction, &c. 7. By examining what operations the fire hath upon several kinds of Salts, what changes it causes in their figures, Textures, or {30} Vertues. 8. By examining their manner of dissolution, or acting upon those bodies dissoluble in them and the Texture of those bodies before and after the process. 9. By considering, by what and how many means, such and such figures, actions and effects could be produced, and which of them might be the most likely, &c.
He goes on to offer his thoughts about the Pores of bodies, and a _kind_ of _Valves_ in wood; about spontaneous generation arising from the Putrefaction of bodies; about the nature of the Vegetation of mold, mushromes, moss, spunges; to the last of which he scarce finds any Body like it in texture. He adds, from the naturall contrivance, that is found in the leaf of a Nettle, how the stinging pain is created, and thence takes occasion to discourse of the poysoning of Darts. He subjoyns a curious description of the shape, _Mechanism_ and use of the _sting_ of a _Bee_; and shews the admirable Providence of Nature in the contrivance and fabrick of _Feathers_ for Flying. He delivers those particulars about the Figure, parts and use of the head, feet, and wings of a Fly, that are not common. He observes the various wayes of the generations of Insects, and discourses handsomely of the means, by which they seem to act so prudently. He taketh notice of the _Mechanical_ reason of the _Spider's_ Fabrick, and maketh pretty Observations on the hunting Spider, and other Spiders and their Webs. And what he notes of a Flea, Louse, Mites, and Vinegar-worms, cannot but exceedingly please the curious Reader.
Having dispatched these Matters, the Author offers his Thoughts for the explicating of many _Phænomena_ of the Air, from the _Inflexion_, or from a _Multiplicate Refraction_ of the rays of Light within the Body of the _Atmosphere_, and not from a _Refraction_ caused by any terminating _superficies_ of the Air above, nor from any such exactly defin'd _superficies_ within the body of the _Atmosphere_; which conclusion he grounds upon this, that a _medium_, whose parts are unequally _dense_, and mov'd by various motions and transpositions as to one another, will produce all these {31} visible effects upon the rays of Light, without any other _coefficient_ cause: and then, that there is in the Air or _Atmosphere, such_ a variety in the constituent parts of it, both as to their _density_ and _rarity_, and as to their divers mutations and positions one to another.
He concludeth with two _Celestial Observations_; whereof the _one_ imports, what multitudes of Stars are discoverable by the _Telescope_, and the variety of their magnitudes; intimating with all, that the longer the Glasses are, and the bigger apertures they will indure, the more fit they are for these discoveries: the _other_ affords a description of a _Vale_ in the _Moon_, compared with that of _Hevelius_ and _Ricciolo_; where the Reader will find several curious and pleasant Annotations, about the Pits of the _Moon_, and the Hills and Coverings of the same; as also about the variations in the _Moon_, and its _gravitating_ principle, together with the use, that may be made of this Instance of a gravity in the _Moon_.
As to the _Inventions of Art_, described in this Book, the curious Reader will there find these following:
1. A _Baroscope_, or an Instrument to shew all the Minute Variations in the _Pressure of the Air_; by which he affirms, that he finds, that before and during the time of rainy weather, the Pressure of the Air is less; and in dry weather, but especially when an _Easterly_ Wind (which having past over vast Tracts of Land, is heavy with earthy particles) blows, it is much more, though these changes be varied according to very odd Laws.
2. A _Hygroscope_, or an Instrument, whereby the _Watery steams_, volatile in the Air, are discerned, which the Nose it self is not able to find. Which is by him fully described in the Observation touching the _Beard of a wild Oate_, by the means whereof this Instrument is contrived.
3. An Instrument for _graduating Thermometers_, to make them _Standards_ of _Heat_ and _Cold_.
4. A _New Engine_ for _Grinding Optick Glasses_, by means of which he hopes, that any Spherical Glasses, of what length {32} soever, may be speedily made: which seems to him most easie, because, if it succeeds, with one and the same Tool may be ground an _Object Glass_ of any length or breadth requisite, and that with very little or no trouble in fitting the _Engine_, and without much skill in the _Grinder_. He thinks it very exact, because to the very last stroke the Glass does regulate and rectifie the _Tool_ to its exact Figure; and the longer or more the _Tool_ and _Glass_ are wrought together, the more exact will both of them be of the desired Figure. He affirms further, that the motions of the Glass and Tool do so cross each other, that there is not one point of eithers surface, but hath thousands of cross motions thwarting it, so that there can be no kind of _Rings_ or _Gutters_ made, either in the _Tool_ or _Glass_.
5. A _New Instrument_, by which the _Refraction_ of all kinds of Liquors may be exactly measured, thereby to give the Curious an opportunity of making Trials of that kind, to establish the _Laws_ of _Refraction_, to wit, whether the _Sines of the Angles of Refraction are respectively proportionable to the Sines of the Angles of Incidence:_ This Instrument being very proper to examine very accurately, and with little trouble, and in small quantities, the _Refraction_ of any Liquor, not only for _one_ inclination, but for _all_; whereby he is enabled to make accurate _Tables_. By the same also he affirms to have found it true, that what _proportion_ the _Sine_ of the Angle of the one _inclination_ has to the _Sine_ of its Angle of _Refraction_, correspondent to it, the same proportion have all the other _Sines_ of Inclination to their respective _Sines_ of _Refractions_.