this for every country on the globe. By his diagram it appears that it will be annular in England, France, Turkey and even Cochin China.

Duvaucel has alfo delineated the eclipfe of February 11th, 1804, which will be total and in fome countries annular, accord

ing to the fun's altitude. It is fuppofed fome voyages will be undertaken on this occafion for determining the differences of the fun's and moon's diameters, the irradiation and inflection.

In the Philofophical Tranfactions for 1799 there is a new method of difcovering the longitude by two altitudes of the fun, and the interval of time elapfed, by Mr. Lax, Aftronomical Profeffor at Cambridge. Alfo a fourth catalogue of ftars, by Herschel, in order to ascertain their degree of light.

The Tranfactions for 1800 contain a very curious Memoir by Herschel, on the power which telescopes poffefs of penetrating into fpace; viz. rendering visible very remote and faint objects, which, by their want of light, would be imperceptible were it not for the affiftance of inftruments; useful remarks on the difference between that force of light and that of enlargement; on the fevcral cafes to which either may apply and the means of procuring a proper degree of light. Herfchel likewife calculates the lofs of light occafioned by mirrors. To him it appears that the greateft amplification does not exceed what is produced by a telescope of from 20 to 25 feet. The opinons of fuch a celebrated optician are worthy of credit. In the tranfactions for 1800, Herschel gives a paper on the different influence of folar rays; the yellow rays, he remarks, illuminate moft, while the red communicate the greatest degree of heat.

PRESENT STATE OF CHEMISTRY IN GERMANY. Extracted from a letter from Dr. Girtanner to Van Mofs.

"TH

HE fyftem of chemistry in Germany has undergone a revo ution. The exiftence of phlogifton is no longer defended, but by Gren (a man of diftinguished talents, though obftinate,) Weftrumb, Gmelin and Crell. The three last have declared eternal war against the anti-phlogistic doctrine. Their enthusiasm even proceeds fo far that, if we ftill lived in the age of martyrdom, they would not hesitate to fuffer themfelves to be burnt, in order to prove the existence of phlogiston in their bodies. Trommsdorf, who has embraced the new doctrine, ftill adheres, however, in fome fmall points to the old. Gottling defends his new hypothefis. Among our young chemists, Scherer of Jena promises great things. He is a zealous follower of the French chemistry, a good experimenter, and poffeffed of great knowledge; there is nothing but the res angufta domi which prevents him from labouring and making new difcoveries. Profeffor Mayer at Erlangen is a man

of great talents, who to natural philofophy and chemistry unites a profound knowledge of the mathematics like Monge at Paris. Hermbftädt does every thing he can for the advancement of the new doctrine. The above is a faint sketch of the present state of chemistry in Germany.

"As my occupations have not permitted me to continue my experiments on phofphorus and alkalies, I'am unwilling to communicate to you those I have made, until I repeat them: I will, however, venture to affure you, that phosphorus is a compound of azot and hydrogen. All phofphorus contains more or less carbon; but, in my opinion, that principle does not enter into its compofition.

66

"I have proved that phofphorus may fhine in azotic gas and carbonic acid gas by means of the water which thefe gafes contains, and which the phofphorus decompofes; as is proved by the phofphorated hydrogen gas obtained in thefe experiments. I explain by this the experiments of Göttling. I wait with impatience for the memoir you have announced, and in which you have prored that I was deceived in regard to the muriatic radical. I fhall repeat the experiments; and whatever be the refult, fhall render homage to truth."

The following obfervations on the above letter have been published by Van Mons : This letter might induce people to believe that the four chemifts, of whom Girtanner fpeaks, ftill profefs the principles of the theory of Stahl. On this fubject, I ought to undeceive thofe who have been prevented by the war from being fully acquainted with the progrefs of the new chemistry in Germany. That country has ceafed to have among its chemical writers any partizan of the unqualified fyftem of phlogifton, fince I convinced them of the prefence of oxygen in the oxyd of red mercury. They have all adopted the new doctrine without reftriction, or with reftrictions of very little confequence. Crell, Weftrumb, Wiegleb, Trommfdorf, Gmelin, Richter, Leonardi, &c. in endeavouring to unite the new theory with the existence of phlogiston in combuftible bodies, all admit it in general and all its confequences. They wish only to fave themselves from the appearance of a complete defeat. Thofe who ftill adhere to the prefervation of that agent, confider it as the bafis of light, or as dormant light. This bafis, abundantly contained in inflammable substances, when it meets and combines itself with caloric, conftitutes luminous fire; which explains why combuftible fubftances require a certain degree of heat before they are inflamed. This fyftem, and the applications of it which follow, are the only points in which they differ from us; in all other explanations they agree perfectly with our principles. We fhall fee how little influence thefe theories modified will have over the future progrefs of found chemistry in Germany.

"Gren, as profound a philofopher as a chemift, a great mathematician and geometrician, no longer attaches any importance to

the admiffion of a particular inflammable matter. His Foundations of the New Chemistry, the first volume of which he has just published, are entirely written according to the principles of the French fyftem. In his Manual of Chemistry, printed two years ago, he gave the theory of oxygen along with that of phlogiston. He did almost the fame thing, the preceding year, in the fecond edition of The Grounds of Natural Philofophy. A third edition of that work is now printing, in which he will give an account of the phenomena of that fcience according to the pure fystem of Lavoifier. His Journal of Natural Philofophy, of which eleven volumes have appeared, has always admitted indiscriminately ar. ticles for and against both theories. That Gren fhould fo long doubt, can astonish those only who are ignorant, that to think for onefelf gives birth to fcepticifm and diverfity of opinions.

1

"Gmelin is exclufively employed, as we may fay, with hiftorical and technical chemistry. In the fecond edition of his Manual of Chemistry, as applied to the Arts, which he has just finished, he gives the little theory required in fuch a work according to the old principles; but in addreffing himself to beginners, ought he not to speak in language that is known and fuited to their comprehenfion? His Introduction to General Chemistry gives an account of the state and progrefs of the fcience of both theories.

His

"Weftrumb gives alfo many articles of technical chemistry, which he treats of with a knowledge and difcernment which denote a chemist well verfed in the practical part of his art. writings on pharmacy evidently fhew that they are the work of a man who has feen much and reflected well on an art where a great deal still remains to be done. In both thefe kinds of labour he prefers facts to reafoning.

"Crell is ftill the editor of the Chemical Annals; a valuable collection, which has tended much to promote the cultivation of chemistry in Germany; and in which he gives, with fidelity, not only the opinions, but even the language of the authors. He ftill finds it difficult to adopt our principles; but at the age of that refpectable literary veteran it is not eafy to abandon old ideas. Befides, Crell has among his fubfcribers and correfpondents some difciples of Stahl, whofe fupport he muft endeavour to retain,"

An Account of TOALDO's Sylem refpealing the Probability of a Change of Weather at the different Changes of the Moon. From Journal des Sciences Utiles.

WER

The

ERE the fun the only caufe of the variations of the weather, the regular course of that luminary, from year to year, would produce the fame weather in the fame feafons. principal variations of the weather, however, depend upon fome other caufe not fo uniform, the difcovery of which has long given employment to philofophers; and as we find that the motion of

the fea feems to have an intimate connection with the motion of the moon, it has thence been believed, that the latter acts a prin cipal part, not only in this phenomenon of the flux and reflux, but that it could not produce these variations on the earth, without having at the fame time, a confiderable influence on the atmofphere. The difference of the fluids which compose it, and, above all, the great elafticity of the air, can alter this effect, but not entirely destroy it.

It is well known that no philofopher has yet been able, from mere theory, to form any proper conclufion refpecting these variations of the weather. To fupply this deficiency, M. Toaldo called in the aid of experience, and compared the state of the atmosphere with the fituation of the moon, where its activity appeared to be strongest and weakest. From obfervations made at Padua on this fubject, during the courfe of fifty years, he at length found that good and bad weather have been always determined by certain fituations of the moon; and this circumstance furnished him the means of foretelling, with fome degree of certainty, the state of the atmosphere by the fituation of that luminary deduced from aftronomical calculations. He diftinguishes ten fituations of the moon, each of which is capable of producing a fenfible effect on our atmosphere; and, in order to comprehend thefe, it must be obferved, that the motion of the moon has three different relations, from which there arife the fame number of revolutions, and that each of these has a particular duration, and at the fame time certain fituations, as expreffed in the following table:

REVOLUTIONS.

1. Synodical, in regard to the fun; continues 29 days 12 hours 44 minutes.

2. Anomaliftic, in regard to the moon's courfe; continues 27 days 13 hours 43 minutes.

3. Periodical, in regard to the moon's paffing the equator; continues 27 days 7 hours 43 minutes.

SITUATIONS OF THE MOON,

New moon
First quarter
Full moon
Last quarter

Apogeum
Perigeum

Afcending equinoxes
Northern luniftices
Defcending equinoxes
Southern luniftices

The fituations of the moon which have a relation to the fynodical revolution are well known. It may, however, be remarked, that new and full moon are called the fyzigies, and the first and last quarter the quadratures. The perigeum and apogeum are comprehended under the term apfides.

On account of the difference in the periods of these three revolutions, the fituations of the moon do not return in the fame order, till after a long feries of years; and in the difference of their coincidence, connected with the regular effect of the fun at

each season, lies the cause of the different variations of the wea ther. The following are the rules which M. Toaldo has deduced from his obfervations.

The probabilities that the weather will change at a certain. period of the moon are in the following proportions;

6: I

That is to fay, a person may bet fix to one, that the new moon will bring with it a change of weather. Each fituation of the moon alters that state of the atmosphere which has been occafioned by the preceding one; and it feldom happens that any change in the weather takes place without a change in the lunar fituations. These fituations are combined, on account of the inequality of their revolutions, and the greateft effect is produced by the union of the fyzigies with the apfides. The proportions of their power to produce variations are as follows: New moon coinciding with the perigeum

with the apogeum
with the perigeum
with the apogeum

33: I

7: I IO : I

8:

I

Ditto The combination of these fituations generally occafions ftorms and tempefts; and this perturbing power will always have the greater effect, the nearer thefe combined fituations are to the moon's paffage over the equator, particularly in the months of March and September. At the new and full moons, in the months of March and September, and even at the folftices, efpecially the winter folftice, the atmosphere affumes a certain character, by which it is diftinguifhed for three, and, fometimes, fix months, The new moons which produce no change in the weather, are those that happen at a distance from the apfides.

As it is perfectly true that each fituation of the moon alters that state of the atmosphere which has been produced by another, it is however obferved that many fituations of the moon are favourable to good and others to bad weather. Those belonging to the latter clafs are the perigeum, new and full moon, paffage of the equator, and the northern luniftice. Those belonging to the former are the apogeum, quadratures, and the fouthern luniftice. Changes of the weather feldom take place on the very days of the moon's fituations, but either precede or follow them. It has been found by obfervation, that the changes effected by the lunar fituations in the fix winter months precede, and in the fix fummer months follow them.