subject: Volta's discovery 2/2 [print this page] Effects of two different substances to the drug frog is stronger, the farther they are separated from each other in the following order: zinc, tin, lead, iron, brass, bronze, copper, platinum, gold, silver, mercury, graphite, charcoal.
From this enumeration contained in 1794, is seen as actively experimenting Volta. He is growing increasingly confident that the source of electricity in Galvani's experiments was not frog muscle, and those two metals, which Galvani to touch it.
But Galvani observed the contraction of muscles and using only one metal! Volta is exploring in detail and this incident also shows that two pieces of copper may contain various impurities that contaminate enough one end of the wire so that it operated as two different metals, a relatively small temperature differences at opposite ends of the same piece of metal that he played role of the stimulus and t,
Finally, the Volta makes the final conclusion: the contact of two different metals is a new source of electricity, which responds to the "live" electroscope. This explains the experiments of Galvani!
This finding reinforces the Volta a whole series of different experiments. For example, the Volta takes a wire of silver and tin, some ends of these wires connect to each other, and the other end for the language: one of the metal tip and the other a little further.
He finds that if the language is applied to the tip money, he felt an alkaline taste, and if the tin - it sour. If the source of electricity was very muscles of the tongue, the taste was not supposed to vary from changes in the closing of the metal, - argues Volta. But if a source of electricity are two dissimilar metals, it is clear that by changing their places, we change the position of "plus" and "minus". In some cases, the electric fluid enters the nerves of the tongue tip, and in the other - out of them. This leads to different tastes. Perhaps the work of all the senses associated with electricity? - Asked Volta (and as we now know, this is the case).
Volta's discovery verifies Galvani and "closes" it
You remember that we are describing an era it was fashionable to put the spectacular experiments. Such experiences are thought Galvani - "electric nerve pendulum" - when a frog leg, suspended on a copper hook, touched the silver casket. (All the matter here in the copper and silver "- would have said Volta.) And Volta also invented a spectacular experience.
Four people were "... form a chain with each other, one touches his finger to the tip of the neighboring languages, the other in the same way to the surface of the eyeball of his other neighbor, and the other two are kept wet fingers one by one leg, and another behind his back svezhepreparovannuyu .. . frog.
Finally, the first in the series of holds in the wet hand zinc plate, and the latter holds a silver plate, and then they bring those records into mutual contact.
At the same time on the top of the language to which touches man, holding in his hand, zinc, will feel the sour taste in the eye? to which a finger touches a neighbor, will feel a flash of light, and at the same time, the frog legs, which are in two hands, will greatly diminish.
All the nerves, which turned out the way of the electric fluid - Language nerves, nerves, eyes and nerves of the frog - are just very sensitive electrometer, and metals from the ground and where there is an effect, not mere conduits, and the "engines" of electricity.
"Thus, instead of talking about animal electricity, could be more right to talk about metal electricity (Volta, 1794). After all, if people in the chain of four people will not keep the silver and zinc, but just touch the hands of each other, then nothing will happen. In Galvani, the category of "living the Leyden jar, which is in the frog, should occur even more successful, in fact closes the circuit was shorter than it was removed from the site, added nothing, but the effect is not. So, this is not the frog, and in metals - in the contact of silver and zinc.
Already from the above examples it is clear that the Volta was right. In his famous treatise Galvani, there is no evidence of "animal electricity".
The observation made Galvani, 26 September 1786, the birthday electrobiology, was the cause of a purely physical phenomenon, based on which Volta invented the DC source: a galvanic cell, or Voltaic pile.
Voltaic pile
This invention will lead to intense development of the theory of electricity and electrical engineering and make XIX century a century of not only the couple, but also electricity.
Despite help from his friends and followers, support such large naturalists like Alexander von Humboldt, Galvani lost a dispute with Volta. Arguments Volta seemed quite convincing. In 1797 comes the final collapse: for political reasons Galvani expelled from the university. He lost his ability to work and after a year he died.
But this time the Volta mistaken. In all three experiments described above Galvani really had to deal with "animal electricity", which he finally managed to open.
Volta's discovery verifies Galvani and "closes" it
After the invention of DC Volta becomes famous and universally recognized. In 1801, Napoleon invited him to Paris, where the Academy of Sciences, he demonstrates his famous post-volt "Volta died in 1827, aged 82 years and illustrious.
