though the salt of silver is very sparingly soluble in water, a yellowish-brown precipitate suddenly falls down, the liquid becomes clear, and retains nothing but naked sulphuric acid, if the proportion of the sulphate of silver has been sufficient to engage the whole of the chlorine of the auriferous solution. Nitrate of silver has the same effect on the solution of gold, only more marked, on account of its greater solubility; the clear liquid containing the whole of the acid of the nitrate of silver employed. What can be the nature of the precipitate thus obtained? Considering the affinity of chlorine for silver, it would at first be concluded that the silver is in the state of chloruret in this precipitate; but to unite with chlorine the silver should be reduced to the metallic state; therefore, in this case, as no chlorate of silver is formed, and no oxygen given out, the latter must unite with the gold. The precipitate, therefore, must consist of an intimate mixture of chloruret of silver and oxyd of gold. Therefore, if this precipitate is treated with hydrochloric (muriatic) acid, all the oxyd of gold is taken up, and is found in the solution in the state of chloruret. At the same time the precipitate loses its colour, diminishes in bulk, and is reduced to simple chloruret of silver. An artificial mixture of chloruret of silver and oxyd of gold, shows exactly the same appearances with muriatic acid. If the precis pitate is heated by itself in a proper apparatus, a large quantity of pure oxygen gas is obtained.-Annal. de Chimie.

niger, and is not easily altered even at a red heat. It crystallizes in long prisms, and when saturate with sulphuric acid or nitric acid, forms very characteristic salts. In examining the constituent alkaline principles of narcotic plants, much care must be taken, as the venomous properties of the plants are concentrated in them. The vapour is very injurious to the eyes, and the smallest fragment placed on the tongue is extremely dangerous.-Journ. de Physique.

New Metal.-Counsellor Giesse of Dorpat has communicated to the world the discovery of what he at present thinks to be a new metal, extracted from the residue of English sulphuric acid, on distilling it to dryness. One variety left, out of 16 ounces, 9 grains of a white residuum, in which there was no sulphate of lead. It changed colour several times during the experiments made upon it, and he thinks it was formed of the sulphur employed in manufacturing the acid. It is susceptible of oxidation, and its alkaline combinations form double salts with acids. Still the professor's details are judged, on the whole, to be inconclusive.

Vegetable Alkali: Daturium.A substance supposed to be a new vegetable alkali, has been obtained from the seeds of the daturium stramonium, by M. R Brandes, and distinguished by the name daturium. It is combined in the seeds with malic acid, and is obtained in the usual way. It is nearly insoluble in water and cold alcohol, but is soluble in hot alcohol, from which it precipitates on cooling in flocculi. It has been obtained with difficulty in crystals, which are

col

Culture of Opium in Great Britain. Mr. Young, who has successfully and lucratively cultivated British opium, says, in a communication to the Society of Arts, "Last summer I produced 19 pounds of opium, 25 gallons of poppy oil, and at the rate of 40 bolls of early potatoes, from 129 falls 18 yards, being 30 falls less than one acre of ground, by the mode of cultivating communicated to the Society of Arts, and afterwards more particularly detailed in the second and third numbers of the Edinburgh Philosophical Journal, with this diffe rence, that the gatherers lected the milky juice with their thumbs instead of brushes, which I consider to be a material improvement in the mode of gathering; and although I had from twelve to twenty boys, from twelve to fourteen years of age, employed during the season, only two were affected with drowsiness, and I could not be certain whether this was the effect of the absorption of the opium, or of the extreme heat of the weather. By this new mode of gathering the milky fluid of the poppy, one of the boys, more than once during the season of gathering, filled his flask in one day, of ten hours work: the flask contained four teen ounces, which, when evaporated, gave three ounces and two drachms of solid opium. I may observe, that owing to the extreme heat, and want of rain, during the last opium harvest, my plants came so rapidly to maturity, that I did not get so much opium as I probably should have done had there been occasional showers."

New Carrot.-A new description of carrot, called amak, was

last year introduced into Scotland, and is found to be uncommonly productive, as an ounce of the seed raised 36 pecks of this vegetable: one amak weighed 4lbs. 12 ounces, another 4lbs. 10 ounces.

Cork Tree. It is generally believed, that cork is the bark of the cork-tree: on the contrary, it is an excrescence formed by exudation on the cuticle, or outer bark of the tree. The trees are stripped the first time before they are twenty years old, and generally once in eight or ten years after. It would appear, this contributes to their health and vigour; for if left unstripped, they begin to decay in a few years, and, in 50 or 60 years, a whole plantation, thus neglected, is destroyed; but those regularly peeled live and thrive more than 200 years.

When the cork is removed, an exudation takes place, which acquires consistency by the action of the air, and thus the succeeding layer of cork is formed. The oldest trees afford the best cork, which, after every successive peeling, improves in quality.

New Plant.-A plant of the Arbor Tristis has recently been brought to England from the coast of Malabar: at about nine o'clock in the evening, this curious exotic is covered all over with flowers of a beautiful white colour, and a most delicate smell.

Spinage. Mr. Phillips has discovered a marine plant, which he considers a true species of spinage, growing on the beach between Worthing and Lancing in Sussex, the leaves of which are as thick as those of cabbage, and the flavour very superior to the common spinage; yet it is neglected by the neighbouring inha

bitants, and suffered to wither on the shore, either through ignorance of its quality, or their fear of eating any herb that has not found its way into either the market or the garden. As it is a perennial, it cannot fail of being a valuable addition to the gardens of those who have residences near the sea. It should be sown on a heap of decayed sea-weed, covered with large gravel or small flints. The root is of the tap kind, but often branches among the stones on the beach; it is sweeter than even the carrot. The flowers are formed of five petals of a pale green colour, but of so solid a nature, that when expanded they cannot be closed without breaking; but to counteract this apparent inconvenience, and to secure the pollen from the weather, to which from its natural situation it is particularly exposed, each petal forms a kind of hood.

On promoting the early Puberty of Apple and Pear Trees when raised from Seed, by J. Williams, Esq. Many persons inclined to become experimentalists in rais ing fruit-trees from seed, with a view of obtaining new, improved, and more hardy varieties, have been deterred from the attempt by the great length of time requisite for ascertaining the result of their industry; for the appletree, when raised in the common way from the kernel, rarely affords its first blossom before it is eight or ten years old, and the pear tree requires even a longer period, twelve or fifteen summers often elapsing before the leaves of seedling-trees are capable of forming their first blossom-buds. In November and December, 1809, I sowed the kernels of several ripe

pears, in separate pots, and placed them in a green-house during the winter. They began to vegetate in the following month of February, and in March the pots were removed into my grapery, where they remained till after Midsummer. The plants were then carefully removed into a seed-bed, and planted in rows, about fourteen inches apart, where they remained till the autumn of 1811, when they were again transplanted into a nursery, at distances of six feet. Every succeeding winter I pruned away all small trifling lateral shoots, leaving the stronger laterals at their full length to the bottom of the plants, and made such a general disposition of the branches, as that the leaves of the upper shoots might not shade those situated underneath; every leaf, therefore, was thus rendered an efficient organ, by its full exposure to the light. At the height of about six feet, I had the satisfaction to observe, that the branches ceased to produce thorns, and the leaves began to assume a more cultivated character. Several of these trees afforded blossoms and fruit last year. One seedling Siberian variety of the apple, thus treated, yielded fruit at four years old, and many more at the age of five and six years.

The Golden Pippin.-Mr. Phillips, of Bayswater, who has lately written an historical account of fruits, tells us, that there are at this time a considerable number of the true golden pippin trees growing on the mountains in Madeira, about 14 miles from the capital of that island, and at an elevation of about 3,000 feet above the sea, which regularly

produce abundance of fruit, not withstanding the trunks and branches are covered with a white lichen or moss. Grafts which were sent from these trees by Thomas Harrison, esq. about three years ago, produced fruit at Cheshunt in Hertfordshire the second year, and proved to be the original golden pippin.

In several parts of America these trees are in a thriving state, which has been proved by the excellent quality of the fruit lately sent to this country. In addition to which he tells us he saw, notwithstanding the late unfavourable season, many trees of this variety in Sussex, as healthy

in appearance as most other kinds of apples, particularly in the garden of Messrs. Humphreys, at Chichester, where the fruit was of a size and perfection that he had never seen surpassed.

Mr. Phillips admits that the golden pippin is a more delicate tree than many other varieties, but by no means so much so as is generally supposed, and it only requires, as it deserves, the most genial situation of the orchard to render it as prolific as formerly. About the year 1685 lord Clarendon had, at his seat at Swallowfield, Berks, an orchard of 1,000 golden and other cider pippins.

New Style of Engraving on Copper.-THE new style of engraving upon copper, which Mr. Lizars has invented, is a substitute for wood-engraving, in the same manner as lithography is a substitute for copper-plate engraving; but while Mr. Lizars has given us a cheaper art for a more expensive one, he has also given us a more perfect art for one which is full of imperfections. The invention of lithography, on the contrary, was the substitution of an imperfect for a perfect art, and whatever progress it may yet make, we can never expect it to exhibit that union of bold and delicate touches by which strokeengraving is characterised.

In wood-engraving, all the white parts are cut below the general surface of the wood, while VOL. LXIII.

all the black lines, which constitute the picture, are left on the level of the general surface. Hence it is impracticable to hatch or to leave upon the surface of the wood elevated lines, which cross each other, without cutting out the small white lozenges, which would be a work of immense labour, and by no means perfect, even if it could be accomplished. All the shadings, therefore, in wood engravings, are formed by parallel lines, which never cross one another. In copper-plate engravings, on the contrary, all the black lines are cut below the general surface, while the white parts correspond with the general surface of the copper. The art of hatching is therefore extremely easy in this art, and we have only to cross the lines 2 Ꮓ