Scientific researches, experimental and theoretical, in electricity, magnetism, galvanism, electro-magnetism, and electro-chemistry : With copper-plates / By William Sturgeon. Published by subscription.

  • Sturgeon, William, 1783-1850.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: Scientific researches, experimental and theoretical, in electricity, magnetism, galvanism, electro-magnetism, and electro-chemistry : With copper-plates / By William Sturgeon. Published by subscription. Source: Wellcome Collection.

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    The electro-magnetic Coil Machine, represented by Fig. 7, Plate XII, has already found more general employment amongst medical men than any other form of electrical apparatus whatever. Its external appearance has certainly undergone some change, more to enhance its elegance than its usefulness ; but the principles upon which it was first constructed remain unaltered.# A variety of modes for opening and closing the battery circuit have been devised by different persons, which is one indi¬ cation, at least, of the importance of the apparatus. It is not my business, however, to particularize either the inventors or their inventions, though I may be permitted to say, that the coil machines now made by Mr. Dancer, Optician, Manchester, are the most elegant that I have seen. The Magnetic Electrical Machine, represented by Figs. 1 and 7, Plate XII, has some years since found its way into the specification of a patent, by Mr. Woolrich, of Birmingham, for the purpose of electro-gilding and silvering, notwithstanding my having published the same plan a long time previously, and pointed out its superi¬ ority over that in which Voltaic batteries are used. The first announcement of my apparatus was in a paper read before the Royal Society, June 16th, 1836 (see twelfth Memoir), in which it was stated that I had coated metals from metallic solutions by means of the magnetic electrical apparatus; and in a small work on Electro- Gilding and Silvering, published March 1st, 1842, I particularly stated the application of the same machine in the process of gilding and silvering in the following words:—“ It is now more than seven years since I contrived a Magnetic Electrical Machine, that produced continuous electric currents, by means of which I coated metals with tin, copper, &c. and I have employed the same machine to great advantage in silvering, gilding, and platinizing various kinds of metal of inferior value ; and I have no doubt that in this capacity the magnetic electrical machine will become generally useful. I have pro¬ duced good electrotypes on a small scale by its employment.” I mention these par¬ ticulars to show that the original intention of placing this apparatus in the hands of the public, and alike available to all artizans wishing to employ it, can not be can¬ celled by any attempt to monopolize it by means of a patent of subsequent date. I may also mention the immediate advantages, in the structure and operations of Voltaic batteries, that have been derived from the discovery of the superiority of rolled zinc over cast zinc, whether amalgamated or otherwise. Many new forms of Voltaic battery have appeared since the first announcement of these facts in the year 1830 (see Abstract 12, page 39, also fifth Memoir, page 146), in all of which the inventors have availed themselves of the advantages alluded to. * Having been informed by several medical gentlemen, that, in some cases, it is desirable to transmit the pulsatory currents through those parts of the patient to which they are applied, in one and the same direction, the following simple modification of the apparatus will be the means of accomplishing that object. Let the coil-wire be all of one piece, and upwards of one, thousand feet long, with branch wires, if thought necessary, for regulating the electric force. The discharging apparatus of course, must always be situated between the usual medical directors. By these means no current can pass through the Patient but that which occurs on opening the battery circuit.