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mines the law by which the elements of bodies, electrified by the fame kind of electricity, mutually repel each other. As we cannot give an account of the ballance, without the plate, we shall transcribe our author's law. The repulfive force of two finall globes, electrified with the fame kind of electricity, is, in the inverfe ratio of the fquare of the distance of the centres of the two globes.'

In the fecond memoir, he determines the laws by which the electrical and magnetical fluids act, either in attracting or repelling. He finds, that either the repulfion or the attraction of two electrified globes, and confequently of two electrical molecules, is in the ratio compounded of the denfities of the electrical fluid of the globes, and the inverfe ratio of the fquare of the distance. In a needle from twenty to twenty-five inches long, rendered magnetic, by the method of the double touch,' the magnetic fluid may be fuppofed to be concentered at ten lines (five-fixths of an inch), from the extremity of the needles. Whatever pofition a magnetic needle be placed in, on an horizontal plane, relative to its magnetic meridian, it is always brought to that meridian, by a conftant force parallel to the meridian, and of which the refult always paffes through the fame point of the needle. The attractive force of the magnetic, as well as of the electrical fluid is exactly in the direct ratio of the denfities, and the inverfe ratio of the fquares of the distances.

The third memoir is on the quantity of electricity which an infulated body lofes in a given time, either by the contact of air, more or lefs moift, or through the fupports, more or less electrics per fe. It is difficult to procure bodies, which, when the electricity is accumulated, are perfectly infulating ones. But, when the electricity was not very denfe, a fmall cylinder of Spanish wax' or gum lac, of an inch in diameter, and about an inch and a half long, is fufficient to infulate perfectly an elder ball of about half an inch in diameter. When the air was dry, a fine filk passed through boiling wax, fo as to make a cylinder about of an inch in diameter, would, he found, be equally useful. With thefe precautions our author began a feries of experiments which are comprised in a table. The los was nearly uniform, when the moisture of the air was the fame, and the electric denfity of the balls feemed to diminish on an average about in a minute; when the mafs and the density were very different the lofs, was fill in the fame proportion, or rather was indeed the fame. The fize and the shape as well as the nature of the body make no variety in the event. When we fpeak of moisture, we mean that ftate of water in the air, in which it affects the hair hygrometer; that is, when its affinity to other bodies is greater than to air. In a fecond table, our author collects the refult of experiments, which fhow the decrease of electricity from the incompleteness of the infulating fupports. This part of the fubject is, however, left imperfect: we need only obferve, that the infulating power of gum lac is three times

as great, as that of filk; or, in other words, that the density of the electricity, when the filk is a perfectly infulating body, may be increased triple, to that affecting the infulating power of the gum.

M. le Monnier has next communicated bis obfervations on the first comet of 1785, discovered in January: it is the twenty-third that he has obferved. He fouud it on the seventh of January, in the neck of the Whale, parallel with the ftar of that conftellation; and it was loft chiefly by bad weather when it had arrived nearly between 1 and of the fame constellation. ę If lines were drawn from the points of thefe ftars to the comet, the angle at e would be nearly half a right angle.

M. Mechain difcovered the fecond comet on the eleventh of March, near the ftar of the left shoulder of Andromeda; and M. Meffier continued to obferve it till the 17th of April, when it was obfcured by the twilight. It was then in the wing of Pegafus, and about the middle of the 16th had nearly 10° declination, and 360° right afcenfion. This, of course, is the twenty-fourth comet obferved by this aftronomer.

M. Meffier has also observed the occultation of some stars of the Pleiades by the moon, on the 11th of April, and the 13th of Lecember, as well as the occultation of Venus by the moon on the 12th of April, 1785. The volume concludes with a continuation of the effay on the population of France, which we have mentioned fo fully, in our review of Dr. Price's fermon.

Carol. Lud. L'Heritier Cornus, Specimen Botanicum, fiftens De-. fcriptiones Icones Specierum Corni, minus cognitarum. Paris. Large Folio. Didot.

IT

T was a remark of Scopoli, that the palm of excellence is due to the monographi; thofe authors, who looking only at one object, perceive its relations, dependencies, and contrafts more minutely than those who roam at large, and aim at making a great comprehenfive fyftem. The cornel-tree fhared the attention of Virgil, either as it flourished by grafting on the trunk of a pear-tree, or as it furuifhed, by its light tough wood, arrows and fpears for the warrior. We have lince feen it add a strength to the grafts of the more tender Afiatic cherry, giving to it the name of the cornelian. The cornus is an inhabitant of cold or temperate climates; Africa is too hot for this plant, probably in its whole extent; but it is found in Europe, on the neighbouring coafts of Afia, and in North America: it conftantly avoids the torrid zone. In England we can boast of but two fpecies, the Suecica, and the fanguinea. The cornel alfo is one of the oldeft genera of the ancient botanifts. The cornel of Pliny, the cornus mas of Linnæus, was called by Theophraftus xea; the cornus famifa of Pliny (cornus fanguinea, Lin.) uxgava. On all thefe accounts, M. l'Heritier purposes to give a more fall account of this ge

nus;

aus; to add fome fpecific diflinctions to thofe already known, without mentioning the economical ufes of this tree except accidentally and tranfiently. He gives the effential and the natural character of the plant, and divides the fpecies into two fections; the involucrata umbellatæ, and the cymofæ. Under the first is ranked the Linnæan fpecies cornus Suecica, Canadenfis, Florida mafcula; under the fecond the fanguinea, fe ricea, alba, and alternifolia of Linnæus, with the new fpecies, the circinata, ftricta, and paniculata. Of these the cornus fericea, alternifolia, and Canadentis, befides the new fpecies, are illuftrated by plates; and our author paffes more quickly over those which are known than those which have been lefs accurately described, or with which botanists have been hitherto unacquainted.

The first fpecies is the Suecica, formerly called, in the Flora Laponica, the cornus herbacea, which name Hudfon yet retains, though akered by Linnæus, to avoid the confufion which would arife in confequence of the cornus Canadenfis being alfo herbaceous. M. 'Heritier refers to the figure of Clufius, which is copied by Gerard, Parkinson, and Taberna Montanus, from the laft work of that author; Pallas fuppofes the cornus Suecica and Canadenfis to be only varieties of the fame plant.

Of the cornus Canadenfis, which is found alfo in Labrador and the island of Miquelon, our author has given a plate. From the laft island it has lately been introduced into France, though it is well known in England.

The cornus Florida is chiefly remarkable for its large coloured involucra, and for flowering fo foon as the leaves appear: it grows fo low down as Carolina.

The cornus mafcula is delineated in Clufius, Mathiolus, Zorn, Regnault, &c. It occurs in France, Germany, and, Switzerland, and is chiefly remarkable for the flowers appearing before the leaves. Du Roi's cornus mafcula foliis eleganter variegatis, our author fuppofes to be a variety of the cornus fanguinea.

The first species of cornus nude cymofe is the fanguinea, known every where, and engraved frequently: of the cornus fericea, (arborea, Lin.) a plate is fubjoined. It is found in Pennfylvania and South Carolina. The cornus alba, (Tartarica of Millar), from Siberia and South America, furnishes little that is important.

The cornus circinata appears, from the plate, to be a bold and beautiful plant: its specific character is, cornus ramis verrucofis; foliis orbiculatis, fubtus tomentofis, canis; cymis depreffis. It is found in Pennsylvania, and has been fome time known. It fcarcely, however, ripens its fruit, though it flowers with feemingly fufficient ftrength.

The cornus firicta is another new fpecies, but it flowers too late to ripen its berries. Cornus ramis ftrictis; foliis ovatis, concoloribus, nudiufculis: cymis paniculatis. It refembles in habit the cornus fanguinea and fericea, from which, however, it

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greatly differs in the paniculated flowers. The antheræ are blue.

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The cornus paniculata has its name from the paniculæ being very long it is a beautiful plant from North America, and, for fome months, is loaded with fruit. There are two varieties, cornus ramis erectis; foliis ovatis, fubtus canis; cymis paniculatis & B- cornus cymis, floribus & foliis intermixtis.

It

The last fpecies, cornus alternifolia (Lin. Supplem. 125.) is very fingular, as all the other fpecies have oppofite leaves. is now known to be a plant originally from Pennfylvania, and grows from fifteen to twenty feet in height. The tree flowers in fpring, but the cymæ are unfruitful, or very rarely contain berries. It has been grafted with fuccefs on the cornus fanguinea and cornus alba. The branches are dichotomous, and the petioli longer than in the other species.

M. l'Heritier next examines the dubious or fpurious fpecies. Among thefe he places the cornus Japonica of Thunberg, which Murray has admitted into the last edition of the Vegetable Syftem. Our author fays it is clearly a fpecies of viburnum, from its offeous, lentiform feed, in an unilocular pod; though he confeffes he has not feen the flower. Plukenet's corno fæminæ fimilis, arbufcula Floridana (Pluken. Anial. tab. 385. fig. 1.) M. l'Heritier believes to be a cornel with paniculated flowers; but does not seem to have decided whether it is the cornus ftricta or cornus paniculata.

Cornus foliis citri anguftioribus of Ammanus (Ruth 200, tab. 33), which Du Hamel fuppofed to be cornus alternifolia, was found by Gmelin and Pallas, who examined it on the spot, to be a fpecies of rhamnus. The former fuppofed it to be the rhamnns catharticus; the latter called it the rhamnus dauricus. Our author fufpects that Du Hamel's mistake introduced the difficulty of afcertaining the native foil of the cornus alternifolia; for, on his authority only, was this genus fuppofed to come from Siberia.

Our author next gives a fummary view of the fpecific differences of the various kinds, and then proceeds to the ufc. All the fhrubby corni are used for ornament; the alba and fanguinea afford the best flocks on which the rarer fpecics may be grafted. The wood is hard; but most fo in the cornus mafcula: the Indians in Lodoifia, like the ancient Romans, fill ufe it for arrows. The berries of the cornus mafcula are eatable, and recommended by the European authors on the materia medica; but the Americans prefer the berries of the cornus Florida. Shoepfus tells us *, that a decoction of the cornus Florida is as efficacious, in intermittents, as the Peruvian bark; and that the leaves of the cornus fericea are put, by the inhabitants of America, into tobacco. From the kernels of the cornus fanguinea the Italians frequently exprefs oil.

This author's Materia Medica Americana, chiefly from the vegetable kingdom, has not yet occurred to us in this country.

MONTHLY

MONTHLY CATALOGUE.

POETRY.

Poems. By Sufanna. 4to. 15. 6d. Dilly.

THE

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HE title is fomewhat peculiar.-We never heard but of one Sufanna without a furname. As, however, we cannot fuppofe that these Poems were written by Daniel's well-known cotemporary, we fhall hazard no conjectures on this occafion. Why her name is not given to the public, is fatisfactorily accounted for: because the poems were publifhed without either her knowledge or confent.' Can the editor as fatisfactorily vindicate himfelf for doing fo? He thinks he can, and tells us that Sufanna is but fourteen years old, and in appearance quite a child of her age; that with difficulty he procured fome of her poems; and that they were read with much avidity, and with as much astonishment;' that he trufts the true lovers of nature and fimplicity will read with pleafure thefe artless efforts of fo young a genius, and feel themfelves happy in nourishing a flower which might otherwife have withered in obfcurity.' He difdains, however, the idea of procuring any pecuniary advantage to himself or the young lady. The utmost which is folicited in their behalf is a little approbation, a little fame; that, if poffible, a genius which is naturally retired and fhy, may by thefe means be ftimulated to exert itself, and brought more juftly to appreciate its own force and value.' The preface concludes in the following rapturous manner:

'Hereafter, methinks, I fhall behold her fame, not (as now) glimmering with a faint and pallid luftre, but thining with the brilliancy of a diamond of the first water; not (as at prefent) twinkling in a meteor ray, but glowing a fixed and lucid tar in the literary hemisphere.'

With what pleafing illufions the partiality of friendship will fometimes delude the mind! However extravagant the editor's encomiums may appear, we firmly believe they proceed from actual feeling, and conviction that the poems deferve them. It is cruel to difpel fuch agreeable day dreams, to take away thofe gratiffimi mentis errores that afford fuch pure and harmlets enjoyment. We will therefore throw no envious cloud to obfruct the rifing fplendors of this future poetic luminary, or give a pang to her enraptured editor. From the following little poem written by the young lady on quitting ******** hall, her father's fummer-refidence, the reader may form a judgment of her abilities: it is no unkind nor unfair fpecimen :

• Adicu, sweet spot! here many an hour
I carelessly have tray'd,
And watch'd the flow declining fun,
Nor fear'd the nightly fade.

No

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