results of various experiments I have made; but they have led me to conclude, that the ferruginous substance is phosphate of iron, that is, the oxi'e of iron united with phosphoric acid, which it is well known gives the red colour to the blood of animals. The phosphate of iron therefore, which in animals has the property of giving the lively red colour to the blood, and even the vermilion hue to the skin, serves to colour the solid part of coral, and give it the brilliant sanguineous tinge.

"The first variety, as I have remarked, is esteemed the most perfec; it is more solid than the other kinds, of a fin r and more compact texture, and hence takes a higher polish In the other kinds, in proportion as the bright colour fades, these qualities gradually deerease, so that the white sort, which is the softest and lightest, is very unft to be wrought, and takes but a trifling polish. The deficiency in the quantity of phosphate of iron diminishes the colour, and at the same time decreases the density of its texture; or perhaps the light texture by its porosity permits the water to wash away the colouring matter, and consequently that which would tend to bring it to perfect maturity.

"To this may be attributed the peculiarities of son e corals, in which the trunk is red, and the branches white; or the branches rea within, and externally white; or the branches balf white and half red, which is often seen in coralligenous productions; but the red pa t always proves of firmer texture then he others.

While naturalists have been employed in investigating the origin of coral, and the nature of its

growth, each applying it to dif ferent purposes; the fair sex, OCH cupied by the natural desire of pleasing, have been much indebted to the brilliant colour and fine lustre of this marine production, Coral formed into beads is worn as an ornament of the neck and arms; and there is no doubt, that the lively colour of coral gives additional grace to a fine face and beautiful complexion, which cannot be obtained by the use of the precious stones, so that these can only be considered as ornaments of luxury and show. The ladies who are always led away by fashion, because they consider it as depending on the existing taste of the other sex, laid aside this beautiful ornament, to load themselves with jewels brought from distant countries. Thus coral gave place to other ornaments, the rage of pleasing being only gratified by variety. Works of amber have latterly obtained a very high estimation from the softness of its substance and its transparency.

66

This substance, which for a time was in high repute, and which the discovery of the precious stones had almost thrown into oblivion, has of late, by the accustomed versatility of capricious fashion, recovered its former value, and has rivalled in price even the ofnaments composed of jewels..

When the value of female or naments shall depend no longer on the price or scarcity, but on the effect they produce on the complexion, all will yield to the natural beauty of coral. Most certainly Galatea, emerging from the ocean, would select from the numerous offerings of the nymphs the lucid branches of the coral to adorn herself with, which would alone assimilate

similate with the roundness of her lips, and with the vermilion of her cheeks.

"The working of coral consists in removing the outer bark, and exposing the interior solid and highly coloured part, which takes a fine polish. The coarse part of the bark being removed by the file, it is rubbed with tripoli powder, and lastly, with a metallic earth, which gives the polish. Some bring it to the finest polish imaginable by the use of the oxide of tin.

"The ancients ornamented their swords, bucklers, and helmets with coral; this custom is still in vogue in some part of Asia, where coral is as much esteemed as in the time of Pliny. The soothsayers and priests of that age attributed many mystic properties to it; hence they were in the habit of wearing coral, as well from religious motives, as from regard to its beauty. Para celsus recommends it to be worn round the necks of infants, as an admirable preservative against fits, sorcery, charms, and even against poison. Many other follies of that man are still prevalent, and of great credit with the common people; and it is very usual in the inland parts of Sicily, to see children wearing amulets of coral round the neck for the above purpose. In the cities it is worn by many in the shape of a horn, as a protection against the influence of evil eyes. It was even believed, that coral would drive away devils and evil

spirits, hence perhaps arose the custom of making crowns of it. Nor have the medicinal properties of coral been less exaggerated, as may be sufficiently seen in the writings of Pliny and Dioscorides. It certainly may be considered as an absorbent; it is used in dentifrice powder, in the Alkermes for indigestion, and in the Troches of Carabe.

"The Trapanese appear to have been the first who worked the coral, being induced thereto by the great quantity of it found in their seas. It is asserted, that Antonio Ciminello, a Trapanese, was the first who discovered the art of engraving coral. In the time of King Alphonso the coral fishery was so assiduously, and so advantageously pursued by the Trapanese, that the ministers of that king proposed to subject the fishery to a tax. In the last century, when it was again proposed, instead of a tax, which probably would have ruined this branch of industry, King Ferdinand instituted some very useful regulations in favour of it.

"Beside forming necklaces and bracelets, the Trapanese have the art of engraving it in the same manner as they do amber and shells, and most certainly many of these works display great spirit, boldness, and grace in the execution, talents natural to the genius of the Sicilian nation.

ON

"TU

URKEY has a considerable trade in a composition known by the name of rose pearls; and as this composition is very simple, I imagine it may not be uninteresting to make it known, that it may be imitated in other countries. Nothing more is necessary than to take the petals of fresh gathered roses, and pound them carefully in a cast iron mortar well polished. They are to be pounded till they are thoroughly bruised and form a smooth paste. This paste is to be spread on a sheet of iron, and dried in the air. When it is nearly dry, it is to be pounded again with some rose water, and dried afresh. This is to be repeated, till the mass is reduced to a very fine paste, when it is fashioned into the proper shape with the fingers, or with an instrument similar to that used for cutting pills. The sort of beads thus formed are then perforated for stringing, and the paste is dried afresh, till it becomes very hard. When they are smooth and well polished, they are rubbed with oil of roses, to increase their fragrance and lustre. By this simple process the paste of rose leaves takes a very decided black colour, owing to a combination of the gallic acid in them with iron.

"With a similar paste beads of various colours are formed. The most common, next to the black, are red and blue. The colouring matter is added to the paste. It is possible however, that these red or blue beads, which are said to be nothing but the paste of rose leaves so coloured, may be made of a particular paste; and if I must give my opinion, I should think this is the case, from the difficulty of giving a red or blue colour to a paste so black as that of roses. The red necklaces in question must not be confounded with those made of pimento, or those of the fruit of the red bead vine, abrus precatorius.

Frequently to render the Turkish rose pearls more fragrant, oil of roses, storax, and musk, are mixed with the paste; but this addition makes no alteration in the mode of preparing it.

"The black beads are most prized, either because they set off the colour of the skin to more advantage, or because their perfume is more agreeable. These beads find their way over Europe through Austria, and are of some consequence as an article of trade.

PRODUCTION

"N°

O chemist has hitherto been able to form sugar by chemical agents. It is true, that Four croy and some others supposed, that at some time or other we should perhaps effect the conversion of starch into sugar, as the compo nent parts of these two substances come infinitely near each other.

an

«Starch,' says Fourcroy, nounces itself as a little less carbonated than gum: we may say, that it comes very near to saccharine matter; and we shall see hereafter, that it appears in fact capable of forming it by a particular alteration of its own substance."

"Under the head gum, the same chemist expresses himself as follows: It is not improbable, that art may effect the conversion of gums into saccharine matter; and already I have several times remarked, that an aqueous solution of gum, through which oximuriatic gas is passed, acquires a saccharine taste, mixed with a strong bitterness. This view of the subject, at present quite novel, will lead to many researches, and to useful resulis.'

"It is even pretended, that several authors say they have effected this transmutation of fecula into saccharine matter: but how is it possible, that they should have succeeded, and been silent on a fact of such importance?

"On looking over what has been published by natural philoso

phers, it appears incontestable, that it was reserved for Mr. Kirchoff, of the imperial academy of Petersburgh, to convert starch into gummy matter, and this into saccharine matter.

"His discovery, which opens a new career to vegetable analysis, and may lead to interesting results, has induced Mr. V gel to pursue these new facts. His fir-t experi ments, some particulars of which he has given in the Journal de Physique, differ scarcely in my thing from those of Mr. Kirchoff, except in his observing, that part of the saccharine matter is formed in the course of two hours boiling, and that the proportion of two hundredths of sulphuric acid produces more than that of one bundredth, the quantity mentioned by the chemist of Petersburgh

"Since that time Mr Vogel has followed up his experiments with more care, in order to acquire an intimate knowledge of the saccharine matter, and the mode of its formation.

"To remove every idea of the saccharine matter being the result of simple extraction; a matter that, having escaped fermentation, was concealed by the starch; he washed · the starch with a stream of cold water, before he made use of it.

"When well dried and reduced to powder, he mixed 2 kil [4b. 61 oz. avoird.] with 8 kil. of Seine water, acidulated with 40 gr. [002

of

of the weight of the starch] of sulphuric acid at 56o [1·631].

"He then boiled the mixture in a silver basin for thirty-six hours. There is no danger of its burning, except during the first hour, when it must be kept constantly stirring with a broad wooden spatula. Af ter that time the mixture grows much more fluid, and requires only to be stirred occasionally.

"It is essential to keep up the quantity of water, by adding fresh as it evaporates,

"After this boiling, it is to be clarified when cold by means of charcoal and chalk, and the whole is to be filtered through flannel.

"The liquid having been evaporated nearly to a sirupy consistence, it must be left to cool, that more of the sulphate of lime may fall down; after which the clear liquid is to be decanted off, and the evaporation

finished.

"The sugar thus obtained with two hundredths of sulphuric acid in a silver basin was much more saccharine, and less high coloured, than that made in a basin of tinned copper.

"In general the latter cannot be used for the purpose, the tin being strongly attacked by the long continued boiling. A leaden vessel has been substituted for it with success.

"The 2 kil boiled with two hundredths of sulphuric acid yielded, in several comparative experiments, sometimes a little less, sometimes a little more than 2 kil. of sirup at 33" of the areometer [1295]; so from a mean of them we may conclude, without any material errour, that starch yields its own weight of sirup.

"As many substances have a decidedly sweet taste, for instance sugar of milk, the sweet matter in liquorice, the sweet principle of

Scheele (formed during the action of fat oils on litharge in making plasters), without however, containing an atom of sugar,, Mr. Vogel thought it necessary to ascertaia, in the first place, whether the sweet liquor from starch contained real sugar.

"For this purpose he mixed some yeast with 200 gr [3089 grs.] of sirup of starch in warm water, and put the whole into a phial, communicating with the pneumatic apparatus, by means of a sigmoid tube.

"Fermentation soon took place, with a very brisk extrication of carbonic acid gas.

1

"The 200 gr. of sirup yielded by the fermentation upwards of 5 lit. [near 6 quarts] of carbonic acid gas; and a notable quantity of alcohol was obtained by distillation.

"It is certain, that all sirup of starch contains more or less gum, the quantity of which varies extremely, cording to the time of boiling, and the weight of the acid employed.

The most saccharine sirup evaporated slowly in a stove, and dried in tin moulds, afforded a perfectly transparent elastic substance, in every respect similar to the paste of jujubes.

"The author has no doubt, that apothecaries may avail themselves of the sirup of starch, for all this kind of gummy sacchariue medicaments, particularly those that may remain in a soft state; for the si rup of starch, thus reduced to a solid state, attracts moisture from the air.

"Mr. Vogel substituted the fe cula of potatoes for starch, and equally obtained a very saccharine gummy sirup.

"The gum was separated by boiling