Volume 1

An introduction to the study of chemical philosophy ... a view of the forces which concur to the production of chemical phenomena / [J. Frederic Daniell].

  • Daniell, J. Frederic (John Frederic), 1790-1845
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of chemical philosophy ... a view of the forces which concur to the production of chemical phenomena / [J. Frederic Daniell]. Source: Wellcome Collection.

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    by the will of the Creator, for the maintenance of the order of his creation. Thus much the intellect of a child can comprehend, and to nothing more did that of a Newton attain. The effort which we feel that a mass of iron makes to fall to the ground, is due to an attractive force between it and the earth, which we denominate GRAViTy, and is an universal power of nature; that which we feel the spring make to recover its first position when we press upon it with the hand, is due to the repulsive force of pLasriciry, and is possessed in very different degrees by different kinds of matter. Before we proceed to inquire into the laws which limit the action of these forces, it will be well to indicate certain other varieties both of repulsion and attraction, which will come within the scope of our inquiry. § 14. It was observed by the ancients, and the fact is men- tioned by Theophrastus, that when a piece of amber is rubbed, it acquires the property of attracting light bodies. The Greek term for amber being electron, the unknown cause of this phenomenon has been called execrricrry. It was not till the commencement of the seventeenth century that the same property was found to be conferred, by friction, on various other bodies, as glass, sealing-wax, sulphur, &e.; and later still, that any two dissimilar substances, when rubbed together, with proper precautions, are capable of exerting the same attractive force. Further observation has shown, that after bodies have been thus attracted to the rubbed surface, they will be repelled from it by an equal but opposite force; and the phenomena will be presented to us in a striking light if we suspend a feather from a piece of silk, and approximate to it a tube of glass, which has been rubbed with a silk handkerchief; the feather will be attracted to the tube from a considerable distance, and after attaching itself to it will fly off, and cannot be made again to. approach it. Both this attraction and repulsion will overcome the force of gravitation in the feather, and by its opposition we can estimate the amount of either. § 15. Again, there is an ore of iron which is common in Sweden, which has received the name of Joadstone, from the property which it possesses of pointing, when freely suspended, to the polar star, or load-star, as it was formerly called; it has been known from remote antiquity to possess the property of attracting small pieces of iron; it is said to have abounded in Magnesia, a province of Lydia, and is mentioned by Pliny, under the name of magnes, hence the property derived the name of Maenetism. It 1s capable