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 . REPORT OP CttEMISTRY AND 



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EXPERlMENTALVHILbsOFHYi. 



M AMPERE continues his electro- 

 • mag:n<»tic researches, and has pub- 

 lished a memoir "on the action exerted 

 upoD an electrical current by another cur- 

 rent, by the terrestrial globe, or by a load- 

 stone." 



It is divided into three sections. 



1. On the mutual action of two electrical 

 currents. 



2. On the direction of electrical currents 

 by the action of the terrestrial globe. 



3. On the mutual action between an 

 electrical conductor and a loadstone. 



In this memoir M. Ampere, ascribes 

 the Dinmal Variation of the Needle to the 

 alternate change of temperature of the 

 two regions, during the diurnal rotation of 

 the earth, the influence of temperature on 

 electric actions having been established by 

 M. Dessaignes and others. " We must 

 add," says he, " among the electro-motive 

 actions of the different parts of the earth, 

 that of the magnetic minerals which it 

 contains, and which should be considered 

 as so many voltaic piles. Analogous opi- 

 nions to these have long since been pub- 

 lished by ovr Philosophical Enquirer, who 

 ascribed the phenomena generally to cur- 

 rents of rare media ; the variations, to 

 deflections of the currents by masses 

 through which it would not pass ; the pro- 

 gressive variations, to cycles of those de- 

 flections j and the diurnal variations to the 

 variable heat of the atmosphere. 



In the mutual action of two electrical 

 currents, the directive action, as well 

 as the attractive and repulsive ones, de- 

 pend on the same principle, and are only 

 different effects of one and the same action. 

 M. Ampere then proceeds to examine the 

 mutual action between an electric current 

 and the terrestrial globe, or a magnet, as 

 ■well as that of two magnets on one another, 

 and he shews that they are all referable to 

 the law of two electrical currents, by con- 

 ceiving on the surface and in the interior of 

 a loadstone, as many electrical currents in 

 planes perpendicular to the axis of the 

 loadstone, as we can conceive lines form- 

 ing without intersections shut curves. He 

 concludes, therefore, that the phenomena 

 of the loadstone are produced solely by 

 electricity, and that there is no other differ- 

 ence between the two poles of a loadstone 

 but their position with regard to the cur- 

 rents of which the loadstone consists, so 

 that the South Pole is that which is found 

 .to the right of the currents, and the North 

 Pole that which is found to the left. 

 • This idea of M. Ampere that loadstones 

 are an assemblage of electrical currents, 

 led him to coU-Ceive the plan of imitating 

 their action by spiral conductors, and after 

 ^ooaeiailurea he succeeded. Thus all the 



mystery of the loadstone is resolved, anfl 

 instead of an iiinate property tui generii, 

 the polarity appears to be a mere mechani- 

 cal effect of certain mundane circulations, 

 not of electricity however, but of the media, 

 which themselves produce the phenomena 

 called electric. Dr. WooUaston has been 

 writing on the same subject, but unable to 

 divest himself of the prejudices of educa- 

 tion and habit, seeks to involve JVl. Am- 

 pere's simple theory in some niodifica,tions 

 of repulsion and attraction ! 



A new diving machine, called a Dolphin, 

 has been invented by M. F. Farkas, ap 

 Hungarian. The continental papers have 

 described some of the advantages of the 

 instrument, but not its couslruction. An 

 experiment was made with it at Vienna in 

 the military swimmiug-school at the Prater.^ 

 Count Joseph Esterhazy de Galaiithy, 

 Count Fergas de Ghymes, the acting Cham- 

 berlain Nemes Slagod, and several English- 

 men and persons of distinction were pre- 

 sent. The servant of the inventor plunged 

 with the Dolphin in twenty-four fi^t Wftter, 

 and walked upon the bottom over the 

 whole square of the swimming-school. To 

 prove that there could be no want of light, 

 the inventor sent down a lantern, and when 

 it was taken up again the light wM Still 

 burning. After the man had remained one 

 hour under water, he returned to the sur- 

 face without assistance ; not because he 

 wanted air, but because all who wei-e pre- 

 sent were satisfied with the success of the 

 experiment, and directed that the 'man 

 might ascend. 



The Astronomical Society of London 

 have offered their gold medal and twenty 

 guineas for the best paper on the theory of 

 the motions and perturbation of the Satel- 

 lites of Saturn. The investigation to be so 

 conducted as to take expressly into consi- 

 deration the influence of the rings and the 

 figure of the planet as modified by the 

 attraction of the rings on the motions of 

 the satellites ; to furnish formula adapted 

 to the determination of the elements of 

 their orbits, and the constant eo-efBcient» 

 of their periodical and secular equations 

 from observation : likewise to point o«t the 

 observations best adapted to lead to a 

 knowledge of such determination. 



A substance, supposed to be a new vege- 

 table alkali, has been obtained from the 

 seeds of the datvrium stramonium by M. 

 R. Brandes, and distinguished by the name 

 Daturium- It is combined in the geeds 

 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 cool- 

 ing in flocculi. It has been obtained with 

 difficulty in crystals, which were quadran- 

 gular 



