afcribes folely to the diffolution of the pure air, the principle of which unites itself with the metal; as, in these experiments, the mercury had not acquired any fenfible heat. Two inches and three-quarters of the fame kind of air being placed over water, and electrified in the fame manner during half an hour, loft a quarter of an inch; and being fuffered to ftand twelve hours in the tube, was found to have loft one-eighth of an inch more. This was very nearly the fame diminution of the air that had taken place, when it was electrified over mercury; but, in this cafe, the process appears to be more flow, and the detached principle not fo readily abforbed. The air remaining after these experiments, being tried by the eudiometer, did not differ from unelectrified pure air taken from the fame receiver.

To determine whether the pure air retained any of the acid employed in its production, the Doctor repeated the experiment with air, obtained from red precipitate, confined by an infufion of turnfole, but could not perceive in it the least change of colour. He alfo electrified air, obtained from minium and the vitriolic acid, placed over fome diluted vinegar of lead, but this was not rendered at all turbid.

Three inches of phlogisticated air being electrified, during the first five minutes, were augmented to 3 inches, and, in the next ten minutes, to 3 inches: fome lixivium was then introduced to try' whether this would abforb it; but, upon being electrified fifteen minutes, the column rofe to the height of 3 inches. It was fuffered to stand in the tube till the next day, when it was found to have funk to its original dimenfion.

Nitrous air, confined by lixivium, being electrified during half an hour, loft three-quarters of its bulk; the lixivium appeared to have abforbed a great deal of nitrous acid; and the air remaining in the tube did not feem to differ from common phlogisticated air. Some of the fame nitrous air, confined by lixivium, was, by ftanding three weeks, diminished to half its bulk, and this refiduum alfo proved to be phlogisticated air. Thus electricity very fpeedily effects that feparation of the nitrous acid from nitrous air, which is flowly produced by the lixivium alone.

Inflammable air, obtained from steel filings and the diluted 'vitriolic acid, being confined by an infufion of turnfole, was electrified for ten minutes without any change of colour in the infufion, or any alteration in the dimenfion of the air. The tube, being filled with the fame air to the height of 2 inches, and placed in diluted vinegar of lead, was expofed to the electric ftream during twelve minutes, in which time the inclosed air rofe to five inches; but the vinegar remained perfectly clear. Three inches of inflammable air, obtained from a mixture of Spirits of wine with oil of vitriol, on being electrified for

fifteen.

fifteen minutes, rofe to ten inches; thus dilated, it loft all its inflammability, and when nitrous air was added, no diminution enfued.

A column of alkaline air, obtained by heat from spirit of fal ammoniac, three inches high, was electrified four minutes, and rofe to fix inches, but did not rife higher when electrified ten minutes longer. It appears that this air is not expanded more by the powerful electric ftream from this machine, than by the common spark. Water would not absorb this electrified

air, which was in part inflammable.

The tube, being filled, to the height of an inch, with fpirit of fal ammoniac, and inverted in mercury, was electrified four minutes; in which time, the tube was filled with eight inches of air, which proved to be equally inflammable, and as little abforbed by water, as the alkaline air. Hence Dr. VAN MARUM conjectures that this air is only the volatile alkali rendered elaftic.

The last chapter contains an account of a very ingenious experiment to illuftrate fome phenomena observed in thunderftorms. Two balloons, made of the allantoides of a calf, were filled with inflammable air, of which each contained about two cubic feet. To each of these was fufpended, by a filken thread about eight feet long, fuch a weight, as was juft fufficient to prevent it from rifing higher in the air; they were connected, the one with the pofitive, the other with the negative conductor, by fmall wires about thirty feet in length, and being kept near twenty feet afunder, were placed as far from the machine, as the length of the wires would admit. On being electrified, these balloons rofe up in the air as high as the wire allowed, attracted each other, and uniting, as it were, into one cloud, gently defcended. The rifing of thefe artificial clouds is afcribed to the expansion of the air they contained, in confequence of the repulfive force communicated to its particles by electricity: when in contact, their oppofite electrical powers deftroyed each other, and they recovered their specific gravity, by lofing the caufe of its diminution. In order to render this experiment more perfectly imitative, the Doctor fufpended to the balloon which was connected with the negative conductor, a bladder filled with a mixture of inflammable and atmospherical air, which, being kindled by the fpark that took place on the union of thefe clouds, gave a confiderable explofion. From thefe experiments, the Doctor explains the fudden elevation of the clouds, and the violent showers of rain and hail, which often accompany thunder-ftorms.

Dr. VAN MARUM intends to make confiderable additions to his battery, as he finds that the machine is capable of charging a larger furface of coated glais; and defigns, in his next pub

lication,

lication, to give an account of experiments on femi-metals, and of those which have been propofed to him by other electricians, whom he here invites to communicate any hints, that may tend to further discoveries in this important branch of phyfics.

For the unusual length of this article, perhaps fome apology may be neceffary; but we hope our readers will excufe it, when they are informed, that on account of the plates, and the comparatively small number of copies, this interefting work will probably foon become very fcarce.

ART. XIII.

The Forms of Herkern: corrected from a Variety of Manufcripts, fupplied with the diftinguishing Marks of Conftruction, and tranflated into English, with an Index of Arabic Words, explained and arranged by their proper Roots. By Francis Balfour, M. D. 4to. 1. s. Printed at Calcutta; and fold by Richardson, London.

PERFECT knowledge of the Eaftern languages is a matA ter of great importance to the merchant as well as the linguift. The encouragement which Mr. Haftings gives to every attempt toward illuftrating the antiquity and cuftoms of the Eaftern nations, and to the ftudy of their languages, has, in a great measure, been the means of producing the learned performance before us. It is an edition of a work held in much estimation among the teachers of the Perfian language, and which is put into the hands of every beginner, being more immediately ufeful to ftrangers, as it relates to the common forms of bufinefs and correfpondence. Dr. Balfour has collated feveral manufcripts, in order to render the copy as perfect as poffible; and this will appear to have been a work of no fmall labour and difficulty, when it is confidered that the Perfian manuscripts are extremely inaccurate, the diftinguishing points of letters being often fuperfluous or misplaced, and the letters themfelves contracted and deformed, not to mention the great obfcurity that is occafioned by words being wrongly divided, or written without any diftinction or spaces between them, and even whole books without the divifion of fentences. Dr. B. having given a correct edition, where the words are properly marked and divided, has certainly prefented the learners of this language, and the curious in Eastern literature, with a moft valuable performance: in order to make this work more generally useful, the Doctor has given an English tranflation of the original on the oppofite page, and annexed a copious vocabulary, or dictionary, of Arabic words, with the derivatives under their proper roots.

As the Infha-i herkern contains forms of oriental correfpondence and bufinets, we taal! prefent our Readers with the following hort fpecimen of an Eaftern love-letter: O moon

O moon of the heaven of good nefs! O cyprefs of the garden of affection; O light of the eye of lovers; O joy of the affectionate heart! out of your benignity and kindness you promifed to enlighten the cell of my melancholy with the ray of your exhilarating prefence. Verily, fince that time, the eye of hope is upon the high road of expectation. Since the days you faid, I will come, mine eye is upon the road: why do you burn me with the cauftic of expectation? why don't you come? If agreeable to your promife, you should give, by a joyful fight of you, illuminating brightnefs to the longing eye of your friends; no wonder at the excefs of your kindness.

"Come, come, for I love you with an hundred fouls.

"Come, for I am torn from myself and united with thee.” The Answer to the above.

O afflicted lover and forfaken expectant! I have understood that you long to fee me, and ftill preferve your attachment to me. But you ought not to depend on the promise of beauties; you ought not to fet your heart on their affurances.

Amongst beauties nobody ever met with fidelity; "Nor with any thing but fchemes to torment."

Nevertheless, if the lover be fincere, and content with beholding, what objection is there?

"When lovers are fincere in their affection,

"What harm though beauties attach themselves to them ?" Want of firmnefs will not do; patience is requifite. The moon of my beauty may foon fhine from the window, and the tree of my fature may caft its fhadow on the terrace.

"Patience is bitter, but it bears fweet fruits."

Among the forms of business is the following certificate of the fale of a flave girl.

Khojeh Abdulla, fon of Khojeh Mahommed, being of age, and in full poffeffion of all his faculties, affirms and declares to this effect: "I have fold to Meer Darvaish Mahommed, fon of Mahommed Morad, a flave girl named Gulbehar, of a copper complexion, and middle fize, with grey eyes, high nofe, joined eye-brows, and both ears pierced, fuppofed about twenty years of age, for the fum of twenty current rupees, the half of which is ten, which fum I have received." Thefe few lines were drawn out in court, by way of certificate, on the eleventh of the month Zeekkadeh.'

This work is a curiofity, on account of its being the firft printed book in the Taleek character. Confiderable merit is due to Mr. Wilkins, without whofe affiftance the Infha-i berkern could never have appeared in its prefent form; as is evident from the following paffage in the Preface:

The only printed Perfian character that has hitherto been in use, except in exhibiting fair copies of dictionaries and grammars, has been fubfervient to no public purpose; and is but ill calculated for becoming the channel of authority, or the medium of business, over an extenfive empire, where it is almost unknown, and scarcely underftood; whereas the types which Mr. Wilkins has invented, being a perfect imitation of the Taleek, the character in which all Perfian books are written, and confequently familiar and univerfally read, are not only well calculated for promulgating the edicts of govern

ment,

ment, but for every tranfaction in business where the Perfian character is required.

By this invention (which is perfectly new and peculiar to Mr. Wilkins, and at the fame time the labour of his own hand, from the metal in its crudeft ftate, through all the different stages of engraving and founding) the Perfian language may now receive all the affiftance of the Prefs. The most valuable books may be brought into print; the language may be more eafily and perfectly acquired; and the improvements of the learned and induftrious conveniently communicated to the Public, and preferved to pofterity.'

We congratulate the cultivators of Eaftern literature on the acquifition of fo great an affiftance in facilitating the study of it; and we hope that by this means not only the languages, but the learning and philofophy of the Eaft, will be more generally known among Europeans.

ART. XIV.

De la France et des Etats-Unis, &c. i. e. On France and the United States; or, on the Importance of the American Revolution to the Kingdom of France, and the reciprocal Advantages which will accrue from a commercial Intercourfe between the two Nations. By Stephen Claviere and J. P. Briffot de Warville. 8vo. 6s. Boards. Phillips, London. 1787.

E

VERY nation is benefited by commerce, and the advantages

of a commercial intercourfe between two nations, will always be proportional to the neceffities of the one, and the productions of the other. The Authors of the prefent publication, by comparing the wants of the Americans with the productions of France, and the contrary; and by confidering the relative fituations and circumftances of the two countries, prove, that a well-regulated commerce must be highly beneficial to each.

The first Chapter is employed in defining feveral terms, and in explaining the general principles of a foreign trade [commerce exterieur]. The Authors fhew that a direct trade (i. e. a trade carried on between two nations immediately) is preferable to that which is carried on by the intervention of a third; it enables the merchant to afford his goods at a cheaper rate; and the cheapnefs of goods is the very bafis of a foreign trade. They point out the circumftances which enable a nation to fell its productions cheap, and alfo the circumftances which oblige two nations to enter into a commercial intercourfe. They confider the mutual intereft of the two nations, and the nature of things, to be the only means of establishing a fure trade. Treaties, regulations, laws, and force, are of no effect; all of them muft give way to the nature of things.

The authors next enter into an examination of what is meant

by a balance of commerce. Here we are prefented with fome cuAPP, Rev. Vol. LXXVI.

Sf

rious