metallic substance, analogous to the perfect metals, especially to gold, as many properties are common to both.

Although metals, from their great utility, have been always diligently searched for, yet this has remained undiscovered till lately; which is a very surprising cir- cumstance, and which seems to prove, that platina is not, like the other metals, scattered in different parts of the world, and in all climates. Platina is found in the golden mines of Spanish America, and chiefly in those of Santa Fé near Carthagena, and in the Bail- liwick of Choco in Peru.

This metal was probably known to the workers of these mines long before it was brought into Europe: but as its colour is not very fine, and as it is almost intractable, especially by fusion, without addition, they seem to have neglected it, considering it as some refractory mineral or marcasite: some of them, how- ever, had attempted to melt it, and to make toys of it, as tobacco-boxes and other things of that kind; but this must certainly have been by alloying it with other metals, as we shall soon see the impossibility of their doing it otherwise.

Nevertheless, this metal continued to be so neglec- ted, that it was entirely unknown in Europe till Don Antonio Ulloa, a Spanish mathematician, who accom- panied the French academicians sent by the king of France to Peru to determine the figure of the earth by measuring a degree of the meridian, first mention- ed it in the relation of his voyage, printed at Madrid in the year 1748: but he says little of it, and repre- sents it as an untractable metallic stone, which impe- ded the extraction of gold from the ore when it was in a large quantity. This account was not very like- ly to excite the curiosity of chemists concerning a new perfect metal, and a matter so interesting and surpri- sing as they afterwards found it to be.

But before that time, that is, in 1741, an English metallurgist, called Wood, who had brought from Ja- maica some specimens of it, which he was informed had come from Carthagena, attended more to it, and made some good chemical trials of it. Since that time, several chemists, the chief of which are M. Scheffer,

Vol. VIII.

of the Swedish Academy, and Dr Lewis, of the Royal Society of London, have very particularly exami- ned this singular metal, and have published their ex- periments. Dr Lewis has in some measure exhausted this matter, in four excellent memoirs communicated to the Royal Society. Platina was, nevertheless, little known in France till the year 1758, when Mr Morin collected, translated into French, and publish- ed, an account of all that had hitherto been done upon platina, in a work entitled, Platina, white gold, an eighth metal.

This publication excited the curiosity of French chemists, to whom it was a new and interesting ob- ject; but the difficulty of obtaining a matter so dear, prevented all of them from being able to satisfy their desire of examining it. Messrs Macquer and Beaumé were the only persons who made experiments upon it, which they have published amongst the Memoirs of the Academy for the year 1751.

About the same time also, Mr Margraaf exami- ned platina, and published a dissertation concern- ing it.

These are the only chemists who have examined, at least who published their researches concerning this new metal. But although their number be small, yet their experiments are so numerous, made with such ac- curacy, and in general so consistent with each other, that, by collecting and comparing them, we may ac- quire a certain and almost as extensive knowledge of platina as of the other metals that have been known from time immemorial. The most general and certain results of the experiments made by the above-men- tioned chemists are the following.

Spanish word, is a diminutive of plata, which in that language signifies silver. It is therefore called by the Spaniards little silver. This name is im- proper; since it resembles silver only in being inde- structible, and very imperfectly in its colour. The name of white gold, given to it by some chemists, is more suitable: for we shall see that it resembles gold more than any one metal resembles any other; and hence we shall chiefly compare it to gold.

We do not certainly know the origin and natural history of platina. We can only assert, that all that we see in masses, or worked into forms, is not pure nor in its natural state; for we are certain that it is unfusible, without addition, by the most violent fire of our furnaces, unless perhaps where the fire is blown up by depoliticated air, or when precipitated from aqua regia, as we shall afterwards see. All the platina that is found in the cabinets of curious persons con- sists of small angular grains, the corners of which are a little rounded. It is mixed with a considerable quantity of small black sand, as attractive by mag- nets as the best iron, but insoluble by acids, unfusible, and untractable. This sand is perfectly similar to that which is found at St Quay in Bretagne. The grains of platina are also frequently intermixed with par- ticles of spar and quartz, and sometimes with spangles of gold. Messrs Macquer and Beaumé found a pretty large spangle of gold in the platina examined by them. But these heterogeneous matters are quite fo- reign to platina, and are not combined with it; for it contains nothing extraneous excepting a little gold and mercury, which latter substance it probably receives during the operations for extracting gold from the ores by the means of mercury. These matters may easily be separated from the platina without decomposing it, by washing and by magnets. Some chemists, who know platina only by name, and deny that it is a peculiar metal, have therefore, with great impropriety, advanced, that Mr Margraaf had decomposed it, and had obtained from it gold, iron, and arsenic. The contrary appears from Mr Margraaf's Dissertation. Mr Margraaf only separated the heterogeneous matters which were merely mixed with platina, as other chemists have done; but he is too good a chemist to pretend that he has decomposed it: on the contrary, he does not hesitate to call it a perfect metal, which name is also given to it by all who understand metals.

The colour of the grains of platina is metallic, white, livid, not very brilliant, intermediate between the white of silver and the grey of iron. At first view they resemble large filings of iron. They are smooth, and are nearly as hard as iron; they are somewhat ductile; so that some of them may be flattened upon an anvil, while others are bruised into small pieces.

The specific gravity of platina is very great, and nearly equal to that of gold. In water it loses only something between an eighteenth and a nineteenth part of its weight.

The tenacity of the parts of this metal has not been determined, because it cannot be formed into a proper figure to make the experiment. But if this quality is proportionate to the ductility and hardness of metals, we may presume, that as platina is much harder than gold, its tenacity is also greater, if all the ductility of which it seems susceptible could be given to it by art.

Platina is, like pure gold and silver, free from all smell and taste. It is unalterable by the combined action of air and water, and is no more susceptible than the other perfect metals of acquiring rust. Like them also it is indestructible by the most violent and long-continued fire: but the property which peculiarly distinguishes this metal is its unfusibility by the most intense heat.

As fusion is necessary for the application of metals to use, chemists have made their utmost efforts to melt platina. The most violent heat which could be raised in air-furnaces, or by the united action of several large bellows, has been applied repeatedly, and continued a long time, without success. In all these trials, the grains of platina remained unaltered in form and weight, and were only agglutinated to each other, nearly as sand is by exposure to violent heat, but so slightly, that by the smallest effort they were separable. Messrs Macquer and Beaumé exposed platina during five days and five nights to the greatest heat of a glass-house furnace, which trial did only confirm the unfusibility and unalterability of platina by ordinary fires, as it was found to be only a little agglutinated, and its weight to be a little increased; which latter phenomenon has been also observed by Mr Margraaf, and which was undoubtedly owing to the fixed air absorbed by the calcareous of the imperfect metals mixed with it. Lastly, Messrs Macquer and Beaumé, having exposed platina to the focus of a large burning-glass, melted a little of it in a minute. It first smoked, then emitted sparks, and those parts of it melted well which were exposed to the centre of the focus. These chemists carefully examined the properties of this platina. According to their memoirs, the melted parts were distinguishable from the others by a brilliancy like that of silver, and by a rounded, shining, polished surface. They were easily flattened upon an anvil, and formed into very thin plates without cracking or splitting; so that these grains seemed to be much more malleable than platina in its natural state. These metals by repeated strokes of the hammer became hard and brittle, as all other metals do, particularly gold and silver; and by annealing, their malleability was restored, as it is also to other metals by the same means. After experiments so certain and well authenticated, we cannot doubt that platina is truly a metal, and even a third metal, as perfect in its kind as gold and silver are in theirs. This proposition will be further confirmed by the other properties of platina.

Platina resists as perfectly as gold the action of the vitriolic, marine, or nitrous acids; in a word, of any pure acid, in whatever manner applied. These acids, concentrated or diluted, may be boiled any length of time upon platina without dissolving an atom of it: but a mixture of nitrous and marine acids, aqua regia, the solvent of gold, is also the solvent of platina. Messrs Macquer and Beaumé have observed, that an aqua regia composed of equal parts of the two acids dissolves most of this metal. But, however the aqua regia is made, more of it is required to dissolve platina than gold. These chemists employed a pound of aqua regia to dissolve an ounce of platina. All the acid of this quantity of aqua regia was not indeed employed to dissolve the platina, because much of it was dissipated in vapours during the operation, from the long time employed in the solution; and therefore, if the operation had been performed in close vessels, and by distillation and cohabitation, as Dr Lewis did, a less quantity of aqua regia would have been sufficient; but this is a matter of small importance.

Aqua regia requires to be assisted by the heat of a sand-bath, and also a considerable time, to dissolve platina well. Although the colour of this metal is white, its solution is very yellow, even deeper than that of gold. When a small quantity of platina only is dissolved in aqua regia, or when a saturated solution is much diluted, a beautiful yellow colour is produced, undistinguishable from that of a solution of gold; but while the aqua regia becomes more and more saturated with platina, its colour becomes more and more intense, and at last red; but this apparent redness evidently proceeds from nothing but the intensity of the yellow colour; for this saturated solution is rendered yellow by dilution with water. In this circumstance it is similar to tincture of saffron.

The solution of platina in aqua regia is acid and corrosive, and from it a neutral crystallizable salt may be obtained. When the acids employed are concentrated, and when the solution is nearly saturated, a confused crystallization is formed at the bottom of the matras, which may be found to be a heap of very small, yellow, transparent crystals. These crystals of platina may be obtained much larger and more beautiful by evaporating the solution of platina with a very flow Platina. flow fire, and by cooling it very slowly. The solution of platina tinges the skin and other animal matters with a blackish brown colour in certain circumstances, (in which respect it resembles the solutions of gold, silver, and of mercury); and ether mixed with this solution by agitation quickly separates from it, and becomes tinged with a fine yellow colour, precisely as it does when it is treated in the same manner with a solution of gold. This experiment shews, that ether, and probably other attenuated oily matters, take platina, as they do gold, for aqua regia; and hence we may perceive another instance of the conformity of those two metals. But as ether does not acquire nearly so intense a colour as the solution of platina, we may infer that it only receives a small quantity of this metal. Besides, the platina soon separates spontaneously from the ether.

Platina may be precipitated from its solvent by fixed and volatile alkalis: and these precipitates are all of a yellow brick-colour, when only so much alkali is employed as is necessary to saturate the acid of the solution; but are of a paler colour when a superabundant quantity of alkali is employed, or when they are digested in alkali. Mr Margraaf mentions a very singular fact concerning the precipitation of platina by alkalis; namely, that although vegetable fixed alkali, and even volatile alkali, precipitated this metal from aqua regia; yet the mineral alkali, though in other instances equal in power of union to the former alkali, and superior to the latter, produced no precipitation, even when so much of it was added as to saturate the acid, nor even disturbed the transparency of the liquor. The above colours of precipitates of platina, according to Mr Macquer, proceed from a large quantity of saline matters which precipitate along with them, and which strongly adhere to them, and not from any calcination of this metal, or loss of its phlogiston. The proof of this is, that if the crystals or precipitates of platina be exposed to strong heat, the saline matters which adhere to them are expelled, the colour occasioned by them is lost, and the platina recovers, without any addition, its ordinary metallic state.—However, there is no reason here to suppose an adhesion of saline matter to the precipitate, which never can be proved, and besides is very improbable, since we know not any substance which has so great an attraction for salts as water. Under the article Phlogiston, it is explained how the calx of a metal may be revived merely by heat, without any apparent addition of phlogistic matter.

All the above-mentioned phenomena exhibited by platina treated with acids and alkalis are similar to those which gold exhibits in similar circumstances: but platina has also in this respect some peculiar properties, by which it differs from gold. 1. The solution of platina acquires a deeper colour than that of gold. 2. The precipitate of platina made by volatile alkali does not fulminate as that of gold does. 3. Tin does not produce from the solution of platina a purple precipitate, capable of tinging glass, as it does from a solution of gold.

Neither nitre, which quickly and effectually calcines all imperfect metals; nor corrosive sublimate, the acid of which, being very much concentrated, acts upon almost all metals; nor any other neutral salt, could occasion the smallest alteration upon platina or upon gold.

This singular metal resists, as well as gold does, the action of sulphur, which so powerfully dissolves other metals. From Dr Lewis's experiments we find, that liver of sulphur is capable of dissolving platina, as it does also gold, by fusion. Mr Margraaf's experiments leave this matter uncertain; but if, as we have reason to believe, liver of sulphur does dissolve platina, this is another instance of the conformity of this metal with gold.

Almost all metallic substances are capable of separating platina from aqua regia, as they also separate gold. Platina precipitated by these substances has its metallic appearance. In this respect it conforms with a general rule, that metals precipitated by other metals have their metallic appearance.

Mr Margraaf relates, in his memoir, a great number of experiments which he made to discover the effects of mixing a solution of platina with other metallic solutions, and also of digesting pure platina with these solutions and other saline substances. These experiments furnished many curious and interesting facts; but as several of them do not seem to be consistent with the essential and acknowledged properties of platina, nor even with similar experiments made by other chemists, there seems reason to believe that these singularities observed by this able chemist proceeded from some extraneous matters with which his platina was alloyed. From most of these experiments, as, for instance, from the yellow flowers obtained by subliming platina with sal ammoniac, and from the blue precipitate formed by mixing his solution of platina with a lixivium of Prussian blue, we may conclude, that iron was the metal with which his platina was alloyed, as he himself says.

Platina, like gold, is capable of being alloyed with all metals, and in these alloys exhibits interesting phenomena. Dr Lewis has examined these alloys more carefully and fully than any other person. The following is an epitome of Dr Lewis's observations on the subject.

Platina, although very unsuitable when alone, may however be fused along with other metals with which it is capable of combining. Equal parts of gold and platina may be melted in a violent fire, and the alloy which is formed may be easily poured into an ingot mould. It is whitish, hard, and may be broken by a violent blow. Nevertheless, when it has been well annealed, it is capable of considerable extension under the hammer. One part of platina and four parts of gold may be melted and alloyed with a much less fire than is requisite in the preceding experiment. This alloy is so ductile, that it may be extended into very thin plates, without being broken, or even split at the edges. Dr Lewis observed a remarkable circumstance concerning this alloy, namely, that the platina, which was \( \frac{1}{5} \) of the whole mass, rendered the gold no paler than guineas are, which contain only \( \frac{1}{5} \) of silver.

Silver and platina may be melted and alloyed together in equal parts with a very violent fire. The alloy which is formed is much harder and darker-coloured than silver, and of a large grain, although it preserves some ductility. These qualities are less sensible when one part of platina is added to seven parts of the silver; but this alloy is still coarser-grained and less white than silver. This coarseness of grain shows an imperfect union; and indeed silver and platina do not seem to unite very intimately; for Dr Lewis observes, that when the alloy of these two metals was left after fusion in the crucible, a considerable part of the platina was separated and sunk to the bottom. The platina did not appear to communicate any good quality to the silver, excepting a greater hardness.

Copper seems to be most improved by being alloyed with platina. When indeed a large proportion of platina is added to copper, as equal parts or two-thirds, the alloy is hard, brittle, and coarse; but when a less quantity of platina is added, as from $\frac{1}{2}$ to $\frac{3}{4}$, or even less, a golden-coloured copper is produced, very malleable, harder, susceptible of a finer polish, smoother-grained, and much less subject to calcination and rust, than pure copper.

Dr Lewis was not able to fuse forged iron with platina; which is not surprising, when we consider the refractory qualities of these two metals: but he alloyed platina with cast-iron, by throwing one part of platina to four parts or more of the iron when it was just beginning to flow. This alloy was much harder, and much less subject to rust, than pure iron. It was susceptible of a very fine polish.

Platina may be melted with tin in all proportions, from equal parts of the two metals to 24 parts of tin. This alloy was observed to be so much harder, more brittle, more dark-coloured, and coarser, as the proportion of the platina was larger. No advantage seemed to be acquirable by this alloy. Lead also may be alloyed in different proportions with platina, nearly as tin may; with this difference, that a much greater fire is necessary for the formation of this latter alloy, particularly when the quantity of platina is great. The metal resulting from it has a dark colour, somewhat approaching to a purple or violet, or it easily acquires these colours when exposed to the air. When the two metals fused together are left in a crucible to cool, a considerable part of the platina separates and falls to the bottom, in the same manner as it does from the alloy of silver.

From Dr Lewis's experiments, platina appears to be capable of amalgamating with mercury, but difficultly, and by a very long trituration with water, as, for instance, during a week.

If mercury be triturated with an alloy of gold and platina, it seizes the gold, and does not touch the platina. Dr Lewis proposes this amalgamation as a method of separating these two metals; and it is that which is employed in the ores of Peru, in which gold and platina are mixed together: but we do not yet know whether this separation be perfectly complete.

Platina may be alloyed with bismuth nearly as with lead, and in a similar manner separates from the bismuth after fusion. It gives to bismuth also, as it does to lead, the property of acquiring, by exposure to air, violet, purple, or blue colours. This alloy is always very brittle.

Of all metallic matters, zinc may be most easily alloyed with platina, and most effectually dissolved by fusion. Dr Lewis observed, that these alloys did not appear very different from pure zinc; but that when the proportion of platina is considerable, their grain is closer, their colour less clear and more bluish than of zinc. They do not tarnish nor change colours by exposure to air. Lastly, they are harder than zinc, and have not the semi-malleability of this semi-metal.

With regulus of antimony platina formed a darker and harder compound than the pure regulus.

Dr Lewis has combined platina at the same time with two metallic matters, such as with brats composed of copper and zinc, and with bronze composed of copper and tin. The most singular phenomenon of this latter alloy was, that the copper and tin acting conjointly upon the platina were capable of dissolving more of it than they both could do separately. This alloy was hard, and capable of receiving a fine polish, but is subject to tarnish; which seems to happen to all the alloys of tin or of lead with platina.

Equal parts of platina and brats formed a compound very hard and very brittle, capable of receiving a very fine polish, and not subject to tarnish. It is possible, therefore, that it might be employed for speculums of telescopes, and would be much preferable to those now used; all which have the great disadvantage of tarnishing by exposure to air, and even very quickly.

Dr Lewis does not mention the effects of alloying platina with arsenic; but Mr Scheffer affirms, that if only a twentieth part of arsenic be added to platina when red-hot in a crucible, these two substances will be perfectly fused, and will form a brittle grey mass. This remarkable experiment requires confirmation; for Mr Margraaf, having also treated these two matters together, did not perceive any such action of arsenic upon platina. From one of his experiments we find, that having exposed to a violent fire during an hour a mixture of an ounce of platina with a fusible glass, composed of eight ounces of minium, two ounces of flints, and one ounce of white arsenic, he obtained a regulus of platina, well united and fused, which weighed an ounce and 32 grains, the surface of which was smooth, white and shining, and the internal parts grey, but which nevertheless appeared sufficiently white when it was filed.

The cupellation of platina was one of the most important experiments to be made; because if this operation succeeded perfectly, we might thereby obtain compact and malleable masses of pure platina, in the same state as a metal which had been well fused, and of which all sorts of utensils might be made, if not by casting it, at least by forging. All the chemists who have examined this metal, and particularly Dr Lewis, have used their utmost endeavours to cupel it well. But although they have used every expedient to apply the strongest heat, they have not perfectly succeeded. The scoriification proceeds well at the beginning of the operation, as when gold and silver are cupelled; but the cupellation afterwards becomes more and more difficult; because, as the quantity of lead diminishes, the matter becomes less and less fusible, and at last ceases to be fluid, notwithstanding the most violent heat; and also because, when the quantity of platina is greater than that of the lead, this latter metal is protected, and is not converted into litharge. Hence the regulus obtained is always dark-coloured, rough, adhering to the cupel, brittle, and weighing more than the platina originally employed, from the lead which remains united with it. Melle Macquer and Beaumé appear appear nevertheless to have carried this experiment further than any other chemists, as they kept the matter exposed to a violent fire during a longer time, that is, about 50 hours successively; therefore, although their platina was tarnished and rough on its surface, it was internally white and shining, easily separable from the cupel, and a little diminished in weight; a certain proof that no lead remained in it. This platina was also ductile, and capable of extension under the hammer.

Cupellation is therefore a certain method of applying platina to use, and of forming it into utensils.

Some further and very important experiments have been made on this singular metallic substance by Messrs Buffon, De Lisle, and Morveau. M. Buffon separated, by means of a magnet, five parts out of seven of a parcel of platina. He distinguished two different matters in platina; of which one is black, friable, and attractable by magnets; and the other consists of larger grains, is of a livid white or yellowish colour, much less attractable, and is extensible. Between these two different matters are many intermediate particles, some partaking more of the former, and some of the latter. He thinks that the black matter is chiefly iron; and he says, that he has observed a similar black powder in many ores of iron. M. Morveau found, that a Prussian blue could be obtained from the black part of the platina, by pouring upon it spirit of nitre, and afterwards adding to the solution diluted some phlogisticated alkali; and that the particles of platina which could not be attracted by magnets, did not by this method shew any sign of their containing iron.

But the most important discovery that has been made concerning platina, is a method of melting it, by which it becomes a perfect metal, malleable, and denser than gold. M. De Lisle effected this, by dissolving crude platina in aqua regia, precipitating it from the acid menstruum by sal ammoniac, and by using this precipitate, without addition, in a double crucible, exposed to the intense heat of a forge-fire excited by double bellows. M. Morveau has repeated this experiment. From 72 grains of platina he obtained a regulus, which weighed 50½ grains, and seemed to have undergone a very imperfect fusion; for it did not adhere to the crucible, nor take its form, but seemed to be the platina merely revived. Its specific gravity also was found to be that of water no more than as 10.045 to 1. But it was found to be nearly as malleable as silver; and when it had been sufficiently hammered, its specific gravity was found to be to water as 20.170 to 1. M. Morveau found that he could melt the precipitate with several fluxes; such as, a mixture of white glass, borax, and charcoal, and a mixture of white glass and neutral arsenical salt; and that the regulus thus obtained was more completely fused, but was not malleable, and was capable of being attracted by magnets; whereas the regulus obtained without addition did not give this mark of containing iron. He further found, that by means of the above-mentioned flux of white glass, borax, and charcoal, he could melt crude platina, and could alloy together platina and steel in various proportions.

The sciences, commerce, and arts, must receive great advantages from the application of a new perfect metal to useful purposes, which to the fixity and indestructibility of gold, unites a hardness and solidity almost equal to those of iron; which is unalterable by the action of water and air; is not subject to rust; and resists, as well as glass or earthen vessels, all salts, even aquafortis and other pure acids. It is to be regretted, that, although large quantities of it are found in America, it is so exceedingly rare here.

The cause of this great scarcity of platina is, that the Spanish ministry have prohibited the sale of it, or the extraction of it from the mines. These prohibitions were certainly from good motives and wise intentions: for this metal was no sooner known, than it was employed for the adulteration of gold; for which purpose it is very fit, as it sustains all the ordinary trials of gold, has the same specific gravity, and renders gold much less pale than silver. The use of a metal with which frauds so prejudicial might be committed with impunity, was necessarily interdicted: but since the best chemists of Europe have examined platina, they have published certain and easy methods by which the smallest quantity of platina mixed with gold may be discovered, and by which these metals may be separated, in whatever proportion they may happen to be united. As a particular detail of these methods would exceed our bounds, we shall here relate only one of the most convenient and least troublesome. It is founded on a property which gold has, and not platina, of being capable of precipitation from aqua regia by martial vitriol; and upon a property which platina has, and not gold, of being capable of precipitation from aqua regia by sal ammoniac. When therefore we would discover if gold be alloyed with platina, let it be dissolved in aqua regia; and to this solution, which will contain both metals, let some sal ammoniac, dissolved in water, be added; upon which the platina will be precipitated in form of a brick-coloured sediment. If, on the other side, we would know if platina contained any gold, let this platina be dissolved in aqua regia, and to the solution add a solution of martial vitriol in water; upon which the liquor will become turbid, and the gold will form a precipitate which may be easily separated by decanting and filtrating the liquor.

We may then affirm, that the reasons which induced the Spanish ministry to interdict the use of platina no longer subsist; and we hope, that, when they are once convinced of this, society shall no longer be deprived of a substance which may be so advantageous to them, and which may be a new source of wealth to the crown of Spain, the sole proprietor of this precious treasure.

* PLATO, a most illustrious philosopher of antiquity, was born at Athens about 430 B.C. He was a person of very great quality; being descended by his father's side from royal ancestors, and by his mother's side from Solon. He was educated in a manner suitable to his rank: he learned grammar, mathematics, music, and painting. In his first years he addicted himself much to poetry; he wrote odes and dithyrambics first, and afterwards epic poetry: which last, finding much inferior to Homer's, he burned. Then he betook himself to writing tragedies, and had prepared one to contend for the prize at the Olympic theatre: but the day before it should have been presented, he happened to hear Socrates, and was so charmed charmed with his way of discoursing, that he not only forbore the contest at that time, but neglected poetry ever after, and even destroyed all his poems.

He was about the 20th year of his age, when he became a follower of Socrates, and began to study philosophy. This great master, soon observing in Plato a greater genius than common, was mightily taken with him; he advised him to read Homer often; and from thence Plato brought himself to conceive and speak of things in a lofty, copious, and striking manner. Plato was equally attached to Socrates: he raised a considerable sum of money to procure his release, after he was imprisoned upon the accusations of his enemies; and when this failed, had the boldness to harangue in defence of him to the people, which he began to do so pathetically, that the magistrates, fearing a tumult, caused him to be silenced. Eight years he lived with Socrates; in which time he committed, as did Xenophon and his other disciples, the substance of his master's discourses to writing. Of this he composed dialogues; but with so great additions of his own, that Socrates, hearing him recite his Lyfs, cried out, "O Hercules! how many things does this young man feign of me!" for, as Laertius adds, many of those things which Plato wrote, Socrates never spoke.

The philosophers who were at Athens were so alarmed at the death of Socrates, that most of them fled the city to avoid the injustice and cruelty of the government. Plato, whose grief upon this occasion is said by Plutarch to have been excessive, retired to Megara; where he was friendly entertained by Euclid, who had been one of Socrates's first scholars, till the storm was over. Afterwards he determined to travel in pursuit of knowledge; and from Megara he went to Italy, where he conferred with Eurytus, Philolaus, and Archytas. These were the most celebrated of the followers of Pythagoras, whose doctrine was then become famous in Greece; and from these the Pythagoreans have affirmed that he had all his natural philosophy. He dived into the most profound and mysterious secrets of the Pythagorean doctrines; and perceiving other knowledge to be connected with them, he went to Cyrene, where he learned geometry of Theodorus the mathematician. From thence he passed into Egypt, to acquaint himself with the theology of their priests, to study more nicely the proportions of geometry, and to instruct himself in astronomical observations; and having taken a full survey of all the country, he settled for some time in the province of Sais, learning of the wise men there, what they held concerning the universe, whether it had a beginning, whether it moved wholly or in part, &c.; and Pausanias affirms, that he learned from these the immortality, and also the transmigration, of souls. Some of the fathers will have it, that he had communication with the books of Moses, and that he studied under one Sechnuphis, a learned man of Heliopolis, who was a Jew: but there is nothing that can be called evidence for these assertions. St Austin once believed that Plato had some conference with Jeremiah; but afterwards discovered, that that prophet must have been dead at least 60 years before Plato's voyage to Egypt.

Plato's curiosity was not yet satisfied. He travelled into Persia, to consult the magi about the religion of that country: and he designed to have penetrated even to the Indies, and to have learned of the Brachmans their manners and customs; but the wars in Asia hindered him.

Being returned to Athens from his travels, he applied to the teaching philosophy, which at that time was the most honourable profession there. He set up his school in the academy, a place of exercise in the suburbs of the city, beset with woods; and this, not being a very healthy situation, brought a quartan ague on him, which lasted 18 months. The physicians advised him to remove to the Lyceum; but he refused, and answered, "I would not live on the top of Athos, to linger away life:" and it was from the academy, that his feet took the name of Academicus. Yet settled as he was, he afterwards made several voyages abroad: one particularly to Sicily, in order to view the fiery ebullitions of Mount Ætna. Dionysius the tyrant reigned then at Syracuse; a very bad man; for, as Cicero relates, after he had robbed a temple at Locris, and was returning by sea to Sicily with a prosperous gale, he said to his companions, "You see, my friends, how the gods favour sacrilege." Plato went to see him; but instead of flattering him like a courtier, reproved him for the disorders of his court and the injustice of his government. The tyrant, not used to disagreeable truths, grew enraged at Plato; and would have put him to death, if Dion and Aristomenes, formerly his scholars, and then favourites of that prince, had not powerfully interceded in his behalf. Dionysius was content to deliver him into the hands of an envoy of the Lacedæmonians, who were then at war with the Athenians; and this envoy, touching upon the coast of Ægina, sold him for a slave to a merchant of Cyrene, who as soon as he had bought him sent him away to Athens. Some time after, he made a second voyage into Sicily in the reign of Dionysius the Younger; who sent Dion, his minister and favourite, to invite him to court, that he might learn from him the art of governing his people well. Plato accepted the invitation, and went; but the intimacy between Dion and Plato raising jealousy in the tyrant, the former was disgraced, and the latter sent back to Athens.

His fame was now spread far and wide; and several states, among which were the Arcadians and Thebans, sent ambassadors with earnest requests that he would come over, not only to instruct the young men in philosophy, but also to prescribe them laws of government. The Cyrenians, Syracusians, Cretans, and Eleans, sent also to him: he did not go to any of them, but gave laws and rules of governing to all. He lived single, yet soberly and chastly. He was a man of great virtues, and exceedingly affable; of which we need no greater proof, than his civil manner of conversing with the philosophers of his own times, when pride and envy were at their height. His behaviour to Diogenes is always mentioned in his history. The Cynic was vastly offended, it seems, at the politeness and fine taste of Plato, and used to catch all opportunities of snarling at him. He dined one day at his table with other company, and, trampling upon the tapestry with his dirty feet, uttered this brutish sarcasm, "I trample upon the pride of Plato;" to which Plato wisely replied, "With greater pride."

The fame of Plato drew disciples to him from all parts: parts: among whom were Speusippus, an Athenian, his sister's son, whom he appointed his successor in the academy; the great Aristotle; two ladies, Laethenia a Mantinian, and Axiothia a Phliasian, who went habited as men, and thereby gave occasion to injurious suspicions of Plato; Hyperides, Demosthenes, and Isocrates, with the last of whom Plato was very intimate. In the mean time, as his great reputation gained him on the one hand many disciples and admirers, so on the other it raised him some emulators, especially among his fellow-disciples, the followers of Socrates. Xenophon and he were particularly disaffected towards each other; and their emulation appears in nothing more than in their having written upon the same subjects. They both wrote a Symposium; they both wrote about Socrates; they both wrote upon government; for the Commonwealth of Plato, and the Institution of Cyrus, are works of the same nature; the latter being pronounced by Cicero, as much a work of invention as the former.

This extraordinary man, being arrived at 81 years of age, died a very easy and peaceable death, in the midst of an entertainment, according to some; but, according to Cicero, as he was writing. Both the life and death of this philosopher were calm and undisturbed; and indeed he was finely composed for happiness. Besides the advantages of a noble birth, he had a large and comprehensive understanding, a vast fund of wit and good taste, great evenness and sweetness of temper, all cultivated and refined by education and travel; so that it is no wonder if he was honoured by his countrymen, esteemed by strangers, and adored by his scholars. The ancients thought more highly of Plato than of all their philosophers: they always called him the Divine Plato, and they seemed resolved that his descent should be more than human. "There are (says Apuleius) who assert Plato to have been sprung from a more sublime conception; and that his mother Perictione, who was a very beautiful woman, was impregnated by Apollo in the shape of a spectre." Plutarch, Suidas, and others, affirm this to have been the common report at Athens. When he was an infant, his father Ariston went to Hymettus, with his wife and child, to sacrifice to the muses; and while they were busied in the divine rites, a swarm of bees came and distilled their honey upon his lips. This, says Tully, was considered as a prelude of his future eloquence. Apuleius relates, that Socrates, the night before Plato was recommended to him, dreamed that a young swan flew from Cupid's altar in the academy, and settled in his lap, thence soared to heaven, and delighted the gods with its music; and when Aristo the next day presented Plato to him, "Friends (says Socrates), this is the swan of Cupid's academy." The Greeks loved fables: they show however in the present case, what exceeding respect was paid to the memory of Plato. Tully perfectly adored him; tells us, how he was justly called by Panætius the divine, the most wise, the most sacred, the Homer of philosophers; entitled him to Atticus, Deus ille noster; thinks, that if Jupiter had spoken Greek, he would have spoken in Plato's language; and made him so implicitly his guide in wisdom and philosophy, as to declare, that he had rather err with Plato than be right with any one else. But, panegyric aside, Plato was certainly a very wonderful man, of a large and comprehensive mind, an imagination infinitely fertile, and of a most flowing and copious eloquence. Nevertheless, the strength and heat of fancy prevailing in his composition over judgment, he was too apt to soar beyond the limits of earthly things, to range in the imaginary regions of general and abstracted ideas; and on which account, though there is always a greatness and sublimity in his manner, he did not philosophise so much according to truth and nature as Aristotle, though Cicero did not scruple to give him the preference.

The writings of Plato are all in the way of dialogue; where he seems to deliver nothing for himself, but everything as the sentiments and opinions of others, of Socrates chiefly, of Timaeus, &c. He does not mention himself anywhere, except once in his Phaedo, and another time in his Apology for Socrates. His style, as Aristotle observed, is betwixt prose and verse: on which account, some have not scrupled to rank him with the poets. There is a better reason for so doing, than the elevation and grandeur of his style: his matter is oftentimes the offspring of imagination, instead of doctrines or truths deduced from nature. The first edition of Plato's works in Greek was put out by Aldus at Venice in 1513: but a Latin version of him by Marsilius Ficinus had been printed there in 1497. They were reprinted together at Lyons in 1588, and at Frankfurt in 1602. The famous printer Henry Stephens, in 1578, gave a most beautiful and correct edition of Plato's works at Paris, with a new Latin version by Seranus, in three volumes folio; and this deservedly passes for the best edition of Plato: yet Seranus's version is very exceptionable, and in many respects, if not in all, inferior to that of Ficinus.