« ПредыдущаяПродолжить »
cutting or destroying the aqueduct, which Goza is about one-third as large as Malta ; from near the other extremity of the island its capital, of the same name, is in the brings water into all the works of Va- centre of the island, although the castle of letta; as the winter rains, being froin Goza is on the sea-lide. Goza is also every where directed to the refervoir, will reniarkable for a wall, said to be of Phæbe found adequate to supply the defi- nician or Carthaginian workmanship; for ciency.
a quarry of alabaster, similar to that in From the fuperior excellence of its har. Ana, and manufactured fiere, although bour, and its advantageous situation with little taste or elegance; and also for in the very centre of the Mediterranean, the fungus rock. The natives of Goza, Malta seems as if especially ordained by as well as the other islands, live princina:ure to favour and protect commerce'; pally on fish, fruits, and leguminous and accordingly it is, and ever has been, plants. The streight between Malta and an emporium and place of refreshment for Goza is about five miles in breadth į all the European vessels which trade in nearly in its centre stands the island of the Mediterranean. It may, in fact, be Cumino, which thus appears formed, as considered as the key and bulwark of this it were, for the defence of the streight, sea and of the Levant ; and, in the hands The breadth of the channel between Sicily of the French, or any other maritime and Malta is computed at froin 40 to 89 power, would certainly become very for- miles, and between Africa and Malta at midable. The utmost extent of the island about 270. is 12 miles in breadth, 20 in length, and The Phænicians first settled in these nearly 6o in circumference. The popula. iflands, about 1500 years before the tion has been constantly increasing, ever christian æra; and their colony here, in fince the establithment of the order there the lequel, became very flourishing: Seto this day; from 10 to go or 60, or, as ven or eight centuries afterwards, the fone say, 20,000 souls, the islands of Greeks, then masters of Sicily, reduced Goza and Cumino included.
the island, and gave it the name of Melité, Cumino, which is very small, and in (changed by the Romans to Melitas), failing by it seems little elle than a bar- on account of the excellent honey found ren rock, contains some inhabitants; and, here in abundance. At the end of about like Malta and Goza, produces the most two centuries, the Carthaginians, whom exquifite oranges and melons, and like the Greeks had suffered to establish them them is covered with citron-trees, date- selves here, made themselves masters of trees, vines, &c. It derives its name it; and they lost it themselves to the Ro. from the cummin it produces, which mans, on the destruction of Carthage. On grows apparently upon the very stones, the division of the Roman empire, it fell Near it is a small uninhabited rock, called to the eastern part, and afterwards beCuminotto.
came alternately the prey of the Goths Goza * is the highest of the three and Vandals. Belisarius drove them itlands, being discernible at tea at the away in 533. The Saracens conquered distance of thirty miles. Moft of the it from the Greek emperors in 870, and Maltese manufactures of cotton (stock- loft it about 200 years afterwards to the ings, coverlids, blankets, and other ituffs) Norman princes reigning in Sicily. It are carried' on in this island. The inhathen parled into the hands of the Gerbitants are accounted more industrious mans; and at length became subject, tothan those of Malta, being almost en- gether with the kingdom of Sicily, to the tirely fecluded froin the world ; and they Duke of Anjou, brother of Louis XI. here cultivate the sugar-cane fuccessfully, Charles of Anjou yielded it up to the though not in any considerable quantityt. kings of Caltile and Arragon, who fre
quently made a grant of it to their fons * Either Malta or Goza is supposed to be
or favourites, or borrowed money upon the celebrated inand of Calypso, firit called it by way of pledge or mortgage. The Hyperia, and afterwards Ogygia. According to inhabitants at length purchaled their fabie, the Pheacians, giants of whom Homer emancipation from this humiliating terspeaks, were the first inhabitants of one or vitude, on condition that their island both of theie ilands. At present, however, should become an unalienable fief of Sicily. they contain noting that resembles the flattering pictures of them to be found in Homer Sicily, inveighed against him, for having, and Fenelon.
among other extravagancies, procured a robe + These islands have been famous for many of cocron to be manufactured at Malta, at an ages for weaving cotton; as we find that Cicero, exorbitant price, to present to fome favourite when pleading against Verres, governor of female.
1799.] Authentic Experiments on the Phenomena of Galvanijin. 189 Under this last title, Charles V. became For the Monthly Magazine. poffeffor of it; and here he establihed the ACCOUNT of EXPERIMENTS made to religious order of St. John of Jerusalem. ascertain the phenomena of GALVAThe knights took possession of the island NISM, by a committee of the physical and in 1530, under the grand master, Villiers mathematical class of the NATIONAL de L'isle Adam, (having lost Rhodes a few INSTITUTE of France*, years before), and remained proprietors - Troveport of these experiments; very unexpected surrender to the French Ge- order in which they were made; but, in a neral BUONAPARTE*.
fort of classification, by means of which In testimony of the original concession their general results are more easily to be of this island, the Grand Master was understood. obliged every year to send a falcon to the The process for producing the very sinKing of Sicily, or his viceroy; and on gular and extraordinary phænomena of every new succession, to swear allegiance Galvanisin, is now well known to all the to the Sicilian monarch, and to receive physiologists in Europe. It consists in from his hands the investiture of these effecting, by the use of the exciting apiflands.
paratus, a mutual communication beThe Maltese nation has för many ages tween any two points of contact, more or kept up the spirit for commerce and ipe lefs distant from one another, in a system culation of its Phænician origin, together of nervous and muscular organs. The with the same fort of indifference for lite- sphere of this mutual communication rature and the fine arts. Of late years, may be regarded as a coinplete circle, however, they have begun to cultivate divided into two parts. That part of it the arts with some success; and they have which consists of the organs of the ani. Aow among them musicians, sculptors, mal under the experiment may be called and painters, not devoid of merit. About twenty years ago, one of the grand master's tion. They have been transated as follows, founded a museum, which was to be the by the Abbé Barthelemi:
“ Abdaffar and Afferemar, sons of Affeproperty of the order: in this were some
remar, son of Abdallar, have made this vow pictures and marble bas-reliefs, (Roman to our lord Melerat, titular God of Tyre: works) found in the country. They may he bless them, after having led them have since added to it a number of fpe- attray cimens of sculpture and medals found The second inscription is in Greek: here, so that it is now full of curiosities “ Dionyfius and Serapion, of the city of and antiques; and the palace of the grand Tyre, tons of Serapion; to Hercules, surmaster abounds with paintings of the most named Archegetes.” famous Italian masters : his library also These fragments were discovered in the contains a number of manuscripts, rare
Villa-Abela, at the bottom of the great hareditions, and beautiful designs. There bour, where formerly a temple' of Hercules is also a public library allere, which is al stood, of which nothing now remains._A
marble statue of that hero has also been found ready of some consequence, and was daily here, which is liighly valued at Malta : it is increasing by the additions of the private two feet in height, but has been injuriously collections of the knights, &ct.
handled by the sculptor who retouched it.
In the muleum are a great number of vafes, * The curious reader may find, in the lamps, and lachrymatories, which are either works of the Abbe de Vertot, and in the Phænician, or of the posterior ages, as they Modern Universal History, interesting details do not possess the elegance of the Grecian relative to the famous fioge in 1565, under vases. It likewise contains a beautiful glass Solyman, and the rest of their history. vase, found in the island, and exactly re
† Some of the copper coins of the Phæni- sembling those discovered at Pompeii; from cians are still to be found here, which
which it is supposed to be Roman.-Among fent a female head, and the deities Orus, las, the Grecian coins, one has been found of the and Osiris, upon the reverse. Carthaginian island of Goza itself; representing a head of coins have been also found here, 'with Punic Diana, with a cresceni upon it, and on the inscriptions. The Romans, when in poffef- reverse a soldier armed with a sword and fion of this island, struck coins with Greek buckler, in the very onset of attack. inscriptions on one side, and Latin on the re- * The members of the committee were verfe. In the museum are two monuments Citizens Coulomb, Sabatier, Pelletan, highly interesting and curious, on account of Charles, Fourcroy, Vauquelin, Guyton, their antiquity, viz. two broken pieces of and Hallé. Citizens Venturi, De Modene, marble candlesticks, with Phænician inscrip- and M. Humboldt, lifted in the experigions upon the pedestals in perfect preserva- menu.
the animal arc; that which is formed of be either mutually continuous, or at least the Galvanic instruments may be called contigu0118 to one another. the excitatory arc. The latter usually contiguity is sufficient to enable the Galconsists of more pieces than one, of which vanic phænomena to take place. some are named Rays, braces, &c. others, 4. The section or ligature of a nerve communicators, from their respective interrupts not the Galvanic phænomena, uses.
if the parts which are cut asunder, or In his report of these experiments, the bound up, still remain in close contiguity writer of it arranges his matter under to one another. thele fix heads : .ift. Results of the diffe. 5. No diversity of the parts forming rent combinations and difpofitions of the the animal arc, though thele be taken parts of the animal arc. 2d. Account of from different parts of the same animal, what has been observed of the nature and or even from different animals, will have the different dispositions of the excitatory power to impair its Galvanic susceptibi
30. Circunstances not entering inió lity, provided only, that these paris be the coinposition of the Galvanic circle, still mutually contiguous. which, nevertheleless, by their influence, 6. If the integrity or Galvanic suscepmodify, alter, or entirely prevent the tibility of the animal arc be suspended by fuccess of the experiments. 4. Means the léparation of any of its parts, to proposed for varying, diminishing, or
fome distance from one another ; it may Teltoring the sensibility to Galvanism. be restored by the interposition 'of fome 5th. Attempts to compare the phæno- substances, not of an animal nature, beniena of Galvanism with those of elec- tween the divided parts. Metallic lubtricity. 6th. Additional experiments, stances are in particular fit for this use. performed by M. HUMBOLDT, in the But the mutual contiguity of all the subpresence of the membets of the commit. Atances entering into the compolition of Tee; which have a referenee to leveral of the arc, inuit ever be carefully preserved. the proofs itated in the foregoing articles. 7. The inuscular organs which indi..
1. To the number of twenty experi- cate, by contraction, the presence of the ments were made on the ANIMAL ARC. Galvanic influence, are always those in The first leven of thele were directed to which the nerves of a complete animal arc ascertain the relations between the nerves have their ultimate termination.* and those muscles, over which they are From this it follows, that the muscles distributed. In the last thirteen, the affected by Galvanism are always those
cut asunder, or subjected corresponding to that extremity of the to ligatures; the fe&tion or ligature be- arc which is the most remote from the ing always between the extremities, of origin of the nerves of which it is com. the arc. Nerves taken from different posed. animals, or from different parts of the 8. When all the nerves of the animal faine animal, and joined in one and the arc originate towards one of its extrefame are, were among the particulas inities, then only those muscles which fubjects of these experiinents; as were correspond with the opposite extremity also the folitary nerve, and the folitary are susceptible of Galvanic convulsions. muscle, included between the extremities 9. When an animal arc consists of more of the excitatory arc. There were inter- than one system of different nerves, which posed too, in the course of these experi- have all their origin about the middle of ments, portions of nerves, and of muscles, the arc, then will the muscles of these distinct from those parts. And in foine several systems of nerves be moved alike of the experiments, the animal was with- at both the extreinities of the arc. out the skin and the epidermis.
10. It seems likewise to appear, from The following are the inferences which a variety of these experiments, that the have been deduced froń thele experi- opinion of those is inadmissible, who
aicribe the phænomena of Galvanism to 1. The animal arc may confilt either the concurrence of two different and reof nerves and muscles together, or of ciprocally correlponding influences, one nerves alone, without muscles.
belonging to the nerve, the other to the 2. Nerves are, therefore, the esential muscle, and who compare the relations part of the animal are; for the muscles between the nerve and the mutile, in these are always more or less interfecied by the phænomena, to those between the interior nerves ; and are, consequently, in part, and the exterior coating of the Leyden a nervous organ.
phiai. 3. All the parts of the animal arc muft 11. It appears, Tastly, that the cover
1799.] Authentic Experiments on the Phanomena of Galvanism. 191 ing of the epidermis, in the entire animal 1. The excitatory arc poteftes the body, acts as an obstacle to the decitive greatest power of Gálvanilm, when it is display of the effects of Galvanism; and composed of at least three distinct pieces; that, thougk from its extreme tenuity, it cach of a peculiar nature; the metals, may not altogether prevent these effects, water, and huinid substances, carboyet it cannot but very materially diminish naceous matters, and animal substances, them.
Atripped of the epidermis, being the only II. The EXCITATORY Arc is usually materials out of which thele pieces may be formed of three different pieces, made of forined. different metals. Of these, one must be 2. Nevertheless the excitatory arc apin contact with the nerve; the other must pears to be not destitute of exciting ener. touch the muscle; and the third must gy, even when it consists but of one piece form the mean of communication between or of several pieces, all of one proper subthese two. This arrangement, though Itance. In general it must be owned, not indispensibly necessary, is at least the identity of nature in the constituent most convenient.
pieces, and particularly in the fupports In respect to the EXCITATORY ARC, forming the extremities of the arc, dithe cominittee examined, ift. The ap- minishes, in a very fenfible manner, its
plication of metallic substances to forin Galvanic energy. it: in respect to which they endeavoured 3. The nightest difference of nature to ascertain the number and the diversity induced upon the parts, whether by any of the pieces of metal, of which this arc feeble alloy, or by friction with extramay be composed ; the metallic mixtures
neous fubitances, is, at any time, fuffior alloys which are capable of being em. cient to communicate to the excitatory ployed for this use; the particular de- aic, that full power in which the idengree of the friction of one metal upon tity of its composition may have made it another, which is favourable to the ex- defective. hibition of the phænomena; the different 4. As the animal arc is susceptible of ftates, in respect to Galvanism, of metais being in part inade up of metallic fube differently mineralized. 2dly, The ef- ftances, or such others as are adapted to fects of the use of carbonic lubstances in enter into the compulition of the excitaforming the excitatory arc. 3dly, The tory arc; lo, on the other hand, the exeffects in the same formation, of bodies, citatory arc admits of being in part which are either non-conductors, or elle formed of thotë substances which are the very imperfect conductors of electricity, proper components of the animal arc. such as jet, alphaltus, sulphur, amber, 5. The energies of both the excitatory sealing-wax, diamond, &c. 4thly, The and the animal arcs, are alike suspended consequences of the interpofition of water', by the separation of their component and of substances moistened with water, parts, or ai least by the reparation of these between the different parts of the excita- parts to a certain distance. tory arc. In forming their excitatory 6. Even the finallest degree of moisture arcs too they made themselves the chord is sufficient to join the parts of the excitaof the arc, they introduced into it animal tory arc, and to determine their effects substances which had loft their vitality; upon the animal arc. they rubbed the supporters with the dry 7. The influence of the state of the at. fingers, so as to mark them with notising moschere, and of Surrounding circumbut the traces of the perspiration from the stances, upon the success of the experiskin. They made, likewise, fome expe- menis of Galvanilin, is, confequentiya riments for the purpose of ascertaining very great. In order therefore to perthe relations between, on the one hand, form these experiments with due accuracy, the extent and magnitude of the surfaces the state of the hygrometer, and of other of the parts composing the arc, and on mettorological initruments, muit be vi. the other, the effects produced by its gilantly intpested, during their progress ; energy, From their experiments they and the intluence of the pertons inaking have allo drawn soine inferences concern- the experiment upon the tphere within ing the relative efficiencies of the several which it is made, milt, likewise, be constituent parts of the exciting arc. It carefully attended to. is impossible for us here to relate in detail 8. The experiments which were made all this train of experiments. The fol- to ascertain the nature of the animal arc, - lowing corollaries exprefs the subltance of together wit! those made upon the exthose general truths, which their authors citatory arc, with a view to the compawere led to infer from them,
rison of the effects of the field of animals, with or without tlre epidermis, and of the and a smart convulfion is, in all these different effects of this epidermis, when cafes, produced at the moment of the it is wet and when it is dry, appear to commencement of the mutual contact, or fuggest to us, that tlre epidermis is one of its ceffation. But, when the frog is of those substances which diminish or in- fatigued, the effects are different. These terrupt the efficacy of the excitatory arc: fuccessive experiments likewise affect the The epidermis is, as well as the hairs results of one another, by means even of and briities of animal bodies, among the their succession folely. And they are also number of those subítances which deserve naturally subject to be influenced by the the appellation of idio-electrics.
nature of the media, amidst which they 9. Examine the substances which are are performed; such as common air, fit for the formation of the excitatory arc, water, an electrical atmosphere. The and you will find that the greater part following are the inferences which have of those which have been successfully put been deduced from this class of these exto this use are substances capable of act- periments. ing as conductors of the 'electrical fluid; 1. In many cases the Galvanic energy but that the substances which interrupt is excited by exercise, is exhausted by the operation of Galvanism are generally continued inition, is renovated by rest. fuch as are well known alle to resist the
2. The multiplicity of the causes by transmission of electricity.
which the experiments of Galvanism are 10. Lastly, it appears, that the Gal. liable to be influenced to success or failvanic energy depends, not only upon the ure, is so great, that we cannot, as yet, nature and arrangenient of the component be too cautious in either rejecting or beparts of the excitatory arc, but on their lieving these accounts which we hear, of extent too, and on the inagnitudes of the success of any such experiments ; untheir transmitting surfaces.
leis when we are able accurately to apIII. The committee appear to have preciate all the influencing circumstances. ured no less care and discernment in ex- 3. This is remarkably confirmed by a periments upon those circumstances, which fact, which the committee have related in though different from the Itructure of the their paper, anıl which respects the conGalvanic circle and its two constituent tinuation of the Galvanic fpatin. arcs, have, however, a decisive influence The communicator being supported by upon the exhibiiion of the phenomena of the hand, and resting, seemingly, without Galvanism. Some curious obfervations change of position, ftill upon the same were made on the differences in the state point of contact, there is known to take of the parts exposed to the Galvanic action. place a real change in the Galvanic conIt was afcertained, that, frogs tres from tact; although the communicator have the ditches, did by no means exhibit the remained thus apparently motionless. fame phænomena as those which had been From this, it may be farther inferred, during some days preferved in the houte; that the smallest possible change in the renor did the limbs of animals, when re- lative situations of the parts of the Galcently stripped of the skin, present the vanic circle and the excitatory arc, is cafame appearances as after they had been pable of producing an effect upon the subjected to a variety of Galvanic experi- fuceptible animal, and of occasioning, ments; nor were the same effects to be mistakes in regard to the fuccefs of the produced upon the parts of animal bodies, experiment, if the utmost care be not which, after a certain number of trials, had taken to notice and estimate every varia. been left for a while at rest, and then taken tion that can happen. up again, as upon those which had been 4. The truth of the foregoing propo. subječted to one continued train of experi- sition is farther confirined, by the experiThe comınitiee next examined
ments upon the manner in which the the variations in the luccess of the expe- Galvanic movements are affected by the riments upon a strong lively frog, which advancing or the withdrawing of the com, may be produced by varying the mode in municator. For these experiments fully which the communicator is carried from the evince the necessity for the most vigilant one supporter to the other: when the com- obfervation of every moment in the promunicator is brought into contact with cols of an experiment, not only collecthe supporter, or is withdrawn from ac- tively, but in their finccession, and at the tual contact with it; wlien the communis different periods of the operation. cator is brought dowly, or when it is 5. It should seem that there are, in the brought rapidly, into contact with the formation of the excitatory arc, independe Supporter; the effects are nearly the same: ently of its modes of acting in the Gal.